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Question 1
Correct
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A 60-year-old man with trauma to his cervical spine suffers from damage to the ansa cervicalis, resulting to paresis of his infrahyoid muscles.
All of the following are considered infrahyoid muscles, except:Your Answer: Mylohyoid
Explanation:Infrahyoid muscles are also known as “strap muscles” which connect the hyoid, sternum, clavicle and scapula. They are located below the hyoid bone on the anterolateral surface of the thyroid gland and are involved in movements of the hyoid bone and thyroid cartilage during vocalization, swallowing and mastication. They are composed of four paired muscles, organized into two layers.
Superficial layer consists of the sternohyoid and omohyoid
Deep layer consists of the sternothyroid and thyrohyoid. -
This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 2
Correct
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A 33-year-old woman who is investigated for recurrent renal stones is discovered to have a markedly elevated parathyroid hormone (PTH) level.
Which of the following would stimulate PTH release under normal circumstances? Select ONE answer only.Your Answer: Decreased plasma calcium concentration
Explanation:Parathyroid hormone (PTH) is a polypeptide containing 84 amino acids. It is the principal controller of free calcium in the body.
PTH is synthesised by and released from the chief cells of the four parathyroid glands that are located immediately behind the thyroid gland.
PTH is released in response to the following stimuli:
Decreased plasma calcium concentration
Increased plasma phosphate concentration (indirectly by binding to plasma calcium and reducing the calcium concentration)
PTH release is inhibited by the following factors:
Normal/increased plasma calcium concentration
Hypomagnesaemia
The main actions of PTH are:
Increases plasma calcium concentration
Decreases plasma phosphate concentration
Increases osteoclastic activity (increasing calcium and phosphate resorption from bone)
Increases renal tubular reabsorption of calcium
Decreases renal phosphate reabsorption
Increases renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol (via stimulation of 1-alpha hydroxylase)
Increases calcium and phosphate absorption in the small intestine (indirectly via increased 1,25-dihydroxycholecalciferol) -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 3
Correct
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A 29-year-old volunteer returns from a recent trip to the middle east with profuse watery diarrhoea. You make a diagnosis of cholera and organize a hospital admission for rehydration with intravenous fluids.
What is the mechanism of action of cholera toxin?
Your Answer: ADP-ribosylation of the G regulatory protein
Explanation:Cholera is caused by Vibrio cholerae, a motile, Gram-negative, curved bacillus. It is transmitted through water and food (especially seafood) and is primarily a disease seen in developing countries where there is poor sanitation and lack of safe water supplies.
The cholera toxin leads to stimulation of adenyl cyclase, ADP-ribosylation of the G regulatory protein, inactivation of GTPase leading to active outpouring of NaCl.
The cholera toxin consists of an A (the toxin) and B subunit. The B subunit attaches to the gut mucosa and presents the A subunit to the cell. The toxin stimulates adenyl cyclase by irreversible ADP-ribosylation of the GTP binding domain of adenyl cyclase leading to the opening of chloride channels resulting in an outpouring of NaCl and water into the lumen of the gut and causing secretory diarrhoea.
Incubation period is between 2 and 5 days, but can be as short as just a few hours.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 4
Correct
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Which of the following is NOT one of the cardinal features of acute inflammation:
Your Answer: Discharge
Explanation:Classic signs:
Rubor (redness)
Calor (heat)
Dolour (pain)
Tumour (swelling)
Functio laesa (loss of function)
These classic signs are produced by a rapid vascular response and cellular events. The main function of these events is to bring elements of the immune system to the site of injury and prevent further tissue damage. -
This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 5
Correct
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A patient suffers an injury to the nerve that innervates piriformis.
The piriformis muscle is innervated by which of the following nerves? Select ONE answer only.Your Answer: Nerve to piriformis
Explanation:Piriformis is innervated by the nerve to piriformis, which is a direct branch from the sacral plexus (S1 and S2).
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 6
Incorrect
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Which type of collagen is initially laid down in early wound healing:
Your Answer: II
Correct Answer: III
Explanation:Fibroblasts migrate to the wound (about 2 – 5 days after wounding), proliferate and secrete extracellular matrix comprising mainly collagen (type III) and fibronectin to plug the gap.
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This question is part of the following fields:
- Pathology
- Wound Healing
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Question 7
Correct
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All of the following statements is considered true regarding Streptococcus pneumoniae, except:
Your Answer: It is the commonest cause of erysipelas
Explanation:Erysipelas is a rare infection of the skin and subcutaneous tissues observed frequently in elderly patients. It is characterized by an acute spreading skin lesion that is intensely erythematous with a plainly demarcated but irregular edge. It is most commonly caused by Streptococcus pyogenes or Group A Streptococcus (GAS).
GAS are susceptible to penicillin, which remains the drug of choice for treatment. For patients allergic to penicillin, erythromycin can be used.
S. pyogenes colonizes the throat and skin on humans, making these sites the primary sources of transmission. Infections resulting from S. pyogenes include pharyngitis, scarlet fever, skin or pyodermal infections, and other septic infections. In addition, the sequelae rheumatic fever and acute glomerulonephritis can occur as a result of infection with S. pyogenes.
Agammaglobulinemia is mostly associated with S. pneumoniae.
The M protein is attached to the peptidoglycan of the cell wall and extends to
the cell surface. The M protein is essential for virulence. The polysaccharide capsule is characteristic of S. pneumoniae. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 8
Incorrect
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A 67-year-old man with chronic breathlessness is sent for a lung function test.
Which statement concerning lung function testing is true?Your Answer: Severe airflow obstruction is defined as an FEV 1 of <55%
Correct Answer: In restrictive lung disease, the FEV 1 /FVC ratio is usually >0.7
Explanation:In restrictive lung disease, the FEV1/FVC ratio is usually >0.7%.
In obstructive lung disease, FEV1 is reduced to <80% of normal and FVC is usually reduced. The FEV1/FVC ratio is reduced to <0.7. Airflow obstruction is defined in the NICE guidelines as:
Mild airflow obstruction = an FEV 1 of >80% in the presence of symptoms
Moderate airflow obstruction = FEV 1 of 50-79%
Severe airflow obstruction = FEV 1 of 30-49%
Very severe airflow obstruction = FEV1<30%. Spirometry is a poor predictor of quality of life in COPD. However, it can be used as part of the assessment of severity of COPD. -
This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 9
Incorrect
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Regarding haemoglobin, which of the following statements is CORRECT:
Your Answer: Foetal haemoglobin remains the primary haemoglobin in infants up until about 1 year of age.
Correct Answer: In degradation of haemoglobin, the haem group is split from the haemoglobin and converted to biliverdin and ultimately to bilirubin.
Explanation:Haemoglobin is composed of four polypeptide globin chains each with its own iron containing haem molecule. Haem synthesis occurs largely in the mitochondria by a series of biochemical reactions commencing with the condensation of glycine and succinyl coenzyme A under the action of the key rate-limiting enzyme delta-aminolevulinic acid (ALA) synthase. The globin chains are synthesised by ribosomes in the cytosol. Haemoglobin synthesis only occurs in immature red blood cells.
There are three types of haemoglobin in normal adult blood: haemoglobin A, A2 and F:
– Normal adult haemoglobin (HbA) makes up about 96 – 98 % of total adult haemoglobin, and consists of two alpha (α) and two beta (β) globin chains.
– Haemoglobin A2 (HbA2), a normal variant of adult haemoglobin, makes up about 1.5 – 3.5 % of total adult haemoglobin and consists of two α and two delta (δ) globin chains.
– Foetal haemoglobin is the main Hb in the later two-thirds of foetal life and in the newborn until approximately 12 weeks of age. Foetal haemoglobin has a higher affinity for oxygen than adult haemoglobin.
Red cells are destroyed by macrophages in the liver and spleen after , 120 days. The haem group is split from the haemoglobin and converted to biliverdin and then bilirubin. The iron is conserved and recycled to plasma via transferrin or stored in macrophages as ferritin and haemosiderin. An increased rate of haemoglobin breakdown results in excess bilirubin and jaundice. -
This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 10
Incorrect
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A 30-year old male is taken to the emergency room after suffering a blunt trauma to the abdomen. He is complaining of severe abdominal pain, however all his other vital signs remain stable. A FAST scan is performed to assess for hemoperitoneum.
If hemoperitoneum is present, it is most likely to be observed in which of the following areas?Your Answer: Spleen
Correct Answer: Liver
Explanation:The Focused Assessment with Sonography in Trauma (FAST) is an ultrasound protocol developed to assess for hemoperitoneum and hemopericardium. Numerous studies have demonstrated sensitivities between 85% to 96% and specificities exceeding 98%.
The FAST exam evaluates four regions for pathologic fluid: (1) the right upper quadrant, (2) the subxiphoid (or subcostal) view, (3) the left upper quadrant, and (4) the suprapubic region.
The right upper quadrant (RUQ) visualizes the hepatorenal recess, also known as Morrison’s pouch, the right paracolic gutter, the hepato-diaphragmatic area, and the caudal edge of the left liver lobe. The probe is positioned in the sagittal orientation along the patient’s flank at the level of the 8 to 11 rib spaces. The hand is placed against the bed to ensure visualization of the retroperitoneal kidney. The RUQ view is the most likely to detect free fluid with an overall sensitivity of 66%. Recent retrospective evidence suggests the area along the caudal edge of the left lobe of the liver has the highest sensitivity, exceeding 93%.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 11
Incorrect
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A man presents to the emergency department with an injury that has damaged the opponens pollicis muscle.
Which of the following statements regarding the opponens pollicis muscle is considered correct?Your Answer: It receives its blood supply from the deep palmar arch
Correct Answer: It flexes the first metacarpal bone at the carpometacarpal joint
Explanation:Opponens pollicis is a muscle of thenar eminence, it is triangular in shape and lies deep to flexor pollicis brevis and abductor pollicis brevis. It originates from the flexor retinaculum, tubercles of scaphoid and trapezium, abductor pollicis longus tendon.
Its insertion is in the radial side of the base of proximal phalanx of thumb. It is supplied by the median nerve (C8, T1). It receives blood supply from superficial arch.
It flexes the metacarpal bone medially across the palm, also rotating it medially, causing opposition, the palmar aspect of the terminal segment of thumb contacts the flexor aspects of any other digit.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 12
Incorrect
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A 24-year-old female visits her family physician to complain of painless lumps in her neck. Her physician notes several enlarged, rubbery, non-tender cervical lymph nodes on examination. He immediately refers the patient for a lymph node biopsy, the results of which show the presence of Reed-Sternberg cells.
What is the diagnosis in this case based on the above scenario?Your Answer: Multiple myeloma
Correct Answer: Hodgkin’s lymphoma
Explanation:The presence of Reed-Sternberg cells is pathognomonic for Hodgkin’s Lymphoma, which is a disease-causing neoplastic transformation of lymphocytes. There is a bimodal age distribution with peaks in the 20s and 60s. Patients typically present with enlarged, rubbery, non-tender lymph nodes. Symptoms such as fever, night sweats and weight loss may be present.
Pain after alcohol consumption is a pathognomonic sign of Hodgkin’s lymphoma, it is, however, not a ‘B’ symptom. It is rare though, only occurring in 2-3% of patients with Hodgkin’s lymphoma.
The Ann Arbour clinical staging is as follows:
Stage I: one involved lymph node group
Stage II two involved lymph node groups on one side of the diaphragm
Stage III: lymph node groups involved on both sides of the diaphragm
Stage IV: Involvement of extra-nodal tissues, such as the liver or bone marrow
Diagnosis is made by lymph node biopsy, which should be taken from a sufficiently large specimen or excisional biopsy, as opposed to a fine needle biopsy.Multiple myeloma most commonly presents with bone pain, especially in the back and ribs.
In non-Hodgkin’s lymphoma, Reed-Sternberg cells are not present.
Acute lymphoblastic leukaemia will present with features of anaemia, thrombocytopenia and leukopenia.
The most common symptoms of chronic lymphocytic leukaemia are fatigue, night sweats and low-grade fever.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 13
Correct
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Which of the following occurs at the transverse thoracic plane:
Your Answer: Bifurcation of the trachea
Explanation:A way to help remember the structures transected by the transverse thoracic plane is CLAPTRAP:
C: cardiac plexus
L: ligamentum arteriosum
A: aortic arch (inner concavity)
P: pulmonary trunk
T: tracheal bifurcation (carina)
R: right-to-left movement of the thoracic duct (posterior to the oesophagus)
A: azygos vein drains into superior vena cava
P: pre-vertebral fascia and pre-tracheal fascia end -
This question is part of the following fields:
- Anatomy
- Thorax
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Question 14
Incorrect
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A known epileptic is transported in status epilepticus by ambulance. On the way to the hospital, she took some diazepam.
Which of the following statements about diazepam is correct?Your Answer: It is a short-acting benzodiazepine
Correct Answer: It crosses into breast milk
Explanation:Diazepam boosts GABA’s effects, giving it sedative, hypnotic, anxiolytic, anticonvulsant, and muscle-relaxing properties. It can be administered orally, rectally, or intravenously.
With a half-life of 20-100 hours, it is a long-acting benzodiazepine. Midazolam, oxazepam, and alprazolam are examples of short-acting benzodiazepines with a half-life of less than 12 hours (Xanax).
If used in the presence of hepatic impairment, benzodiazepines can cause coma. If treatment is necessary, benzodiazepines with shorter half-lives should be used in lower doses. Diazepam is a sedative that crosses into breast milk and should be avoided by breastfeeding mothers.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 15
Incorrect
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The myocardium is responsible for creating the force with which the atrial and ventricular muscles contract. It is made up of myocytes, which are heart muscle cells.
Which of the following statements about cardiac muscle anatomy is correct?Your Answer: Cardiac muscle is non-striated
Correct Answer: Cardiac myocytes have intercalated discs
Explanation:Typically, granuloma has Langerhan’s cells (large multinucleated cells ) surrounded by epithelioid cell aggregates, T lymphocytes and fibroblasts.
Antigen presenting monocytic cells found in the skin are known as Langerhan’s cells.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 16
Incorrect
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C3 deficiency leads to particular susceptibility of infection with which of the following:
Your Answer: Intracellular bacteria
Correct Answer: Encapsulated bacteria
Explanation:Macrophages and neutrophils have C3b receptors and they phagocytose C3b-coated cells. C3 deficiency thus leads to increased susceptibility of infection with encapsulated organisms (e.g. S. pneumoniae, H. influenzae).The early stages of the complement cascade leading to coating of the cells with C3b can occur by two different pathways:The classical pathway usually activated by IgG or IgM coating of cellsThe alternative pathway which is more rapid and activated by IgA, endotoxin and other factors
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 17
Incorrect
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Which of the following cervical nerves is likely to be affected if your patient is complaining of elbow extension weakness and loss of sensation in her middle finger? She also has pain and tenderness in her cervical region, which is caused by a herniated disc, all after a whiplash-type injury in a car accident.
Your Answer: C6
Correct Answer: C7
Explanation:A C7 spinal nerve controls elbow extension and some finger extension.
Damage to this nerve can result in a burning pain in the shoulder blade or back of the arms. The ability to extend shoulders, arms, and fingers may also be affected. Dexterity may also be compromised in the hands or fingers.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 18
Incorrect
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Which of the following clinical features would you NOT expect to see in a tibial nerve palsy:
Your Answer: Loss of flexion of the toes
Correct Answer: Weakened eversion of the foot
Explanation:Damage to the tibial nerve results in loss of plantarflexion of the ankle and weakness of inversion of the foot resulting in a shuffling gait, clawing of the toes and loss of sensation in its cutaneous distribution.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 19
Incorrect
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If the null hypothesis is wrongly rejected when it is actually true, this is an example of:
Your Answer: A test with high power
Correct Answer: A test with a type I error
Explanation:A type I error occurs when the null hypothesis is wrongly rejected when it is actually true and we conclude that there is a difference of effect when in reality there is none (a false positive result).
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 20
Correct
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Which of the following is NOT a side effect of phenytoin:
Your Answer: Ototoxicity
Explanation:Adverse effects of phenytoin include:
Nausea and vomiting
Drowsiness, lethargy, and loss of concentration
Headache, dizziness, tremor, nystagmus and ataxia
Gum enlargement or overgrowth
Coarsening of facial features, acne and hirsutism
Skin rashes
Blood disorders -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 21
Correct
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Na+ is reabsorbed via the Na+/K+/2Cl-symporter in which part of the loop of Henle?
Your Answer: Thick ascending limb
Explanation:In the thick ascending limb is the part of the loop of Henle in which there is active reabsorption of Na+and Cl- ions from the tubular fluid. This occurs via the Na+/K+/2Cl-symporter on the apical membrane.
This mechanism is by:
1. Na+ions are transported across the basolateral membrane by Na+pumps and the Cl-ions by diffusion.
2. K+leaks back into the tubular fluid via apical ROMK K+channels which creates a positive charge.
3. This positive charge drives the reabsorption of cations (Na+, K+, Ca2+, Mg2+) through paracellular pathways.
4. Due to the thick ascending limb being impermeable to water, the tubular fluid osmolality is reduced by ion reabsorption, the interstitial fluid osmolality is increased, and an osmotic difference is created. -
This question is part of the following fields:
- Physiology
- Renal
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Question 22
Incorrect
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A patient who is a known case of rheumatoid arthritis presents to the clinic as his grandson was recently diagnosed with chickenpox. His grandson spent the weekend with her, and he was in close contact with him. He takes 50 mg of prednisolone once daily and has been for the past six months. There is no history of chickenpox.
Out of the following, which is TRUE regarding the next plan of action for her care?Your Answer: She should be placed on a reducing regime to wean down her prednisolone
Correct Answer: She should receive prophylactic varicella-zoster Immunoglobulin (VZIG)
Explanation:Varicella-zoster immunoglobulin (VZIG) is indicated for post exposure prevention and treatment of varicella. It is recommended as prophylaxis for high-risk patients with no known immunity (i.e. no known previous chickenpox) who have had a significant exposure to varicella-zoster (considered >4 hours close contact).
The high-risk groups are:
1. Neonates
2. Pregnant women
3. The immunocompromised (e.g. cancer, immunosuppressive therapies)
4. Those on high dose steroids (children on more than 2 mg/kg/day for more than 14 days, or adults on 40 mg/day for more than a week)This patient is at high risk of developing adrenal insufficiency and may need a temporary increase in her steroid dose during infection or stress. It would be inappropriate to stop or wean down her dose of prednisolone and can cause side effects.
Since he is on steroids without immunity for chickenpox, he is at risk of developing severe varicella infection, with possible complications including pneumonia, hepatitis and DIC.
If he develops a varicella infection, he will need to be admitted and require a specialist review and intravenous Acyclovir.
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This question is part of the following fields:
- Immunological Products & Vaccines
- Pharmacology
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Question 23
Incorrect
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A 61-year-old woman returns to get the results of recent blood tests she had done for non-specific malaise, lethargy, and weight loss.
The only abnormality discovered during the blood tests was a 580 x 10 9 /l increase in platelets. Her platelets were also elevated on a blood test taken 6 months earlier, according to her previous results. You're aware of the recent emergence of elevated platelet levels as a cancer risk marker and decide to look into it.
Which of the following cancers is most likely to cause isolated thrombocytosis?Your Answer: Melanoma skin cancer
Correct Answer: Colorectal cancer
Explanation:Raised platelet levels have emerged as a cancer risk marker, according to a large population-based study published in 2017(link is external). According to the study, 12 percent of men and 6% of women with thrombocytosis were diagnosed with cancer within a year. These figures increased to 18% in men and 10% in women if a second platelet count was taken within 6 months of the first and showed an increased or stable elevated platelet count.
The researchers discovered that thrombocytosis linked to cancer is most common in colorectal and lung cancers, and it is linked to a worse prognosis. Furthermore, one-third of the cancer patients in the study had no other symptoms that would have prompted an immediate cancer referral.
The exact mechanism by which these cancers cause thrombocytosis is unknown, but one theory proposes the existence of pathogenic feedback loops between malignant cells and platelets, with a reciprocal interaction between tumour growth and metastasis, as well as thrombocytosis and platelet activation. Another hypothesis is that thrombocytosis occurs independently of cancer but aids in its spread and progression.
The findings show that routinely testing for thrombocytosis could cut the time it takes to diagnose colorectal and lung cancer by at least two months. In the UK, this could result in around 5500 earlier cancer diagnoses per year.
Because the positive predictive value of thrombocytosis in middle age for cancer (10%) is higher than the positive predictive value for a woman in her 50s presenting with a new breast lump (8.5%), this is clearly an important research paper that should be used to adjust future clinical practise. The current NICE guidelines predate these new research findings, so we’ll have to wait and see how they affect cancer referral guidelines in the UK.
Because there are so many possible cancers associated with thrombocytosis, the treating clinician should take a thorough history and perform a thorough clinical examination if a patient is diagnosed with it. Further investigation and the most appropriate referral route should be aided by this information.
It’s worth noting that the patients in the study had their blood tests done for a medical reason rather than as a random screening test.
If there are no other symptoms to guide investigation and referral (one-third of the patients in the study had no other symptoms), keep in mind that the two most common cancers encountered were colorectal and lung cancer, so a chest X-ray and a faecal immunochemical test (FIT) for faecal blood may be reasonable initial investigations.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 24
Incorrect
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What is the pathophysiology of Cushing's syndrome:
Your Answer: Hyperaldosteronism
Correct Answer: Glucocorticoid excess
Explanation:Cushing’s syndrome is the name given to the clinical symptoms and signs induced by chronic glucocorticoid excess.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 25
Correct
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All of the following statements regarding Helicobacter pylori is considered true, except:
Your Answer: Serum antibody levels should be used to check for successful eradication
Explanation:Helicobacter pylori is a curved, non-spore forming, Gram-negative bacteria that is primarily linked to gastric infections. Once acquired, it colonizes the stomach for a long time and can cause a low-grade inflammatory process, producing a chronic superficial gastritis.
H. pylori can be recovered from gastric biopsy materials. Samples must be transported quickly to the laboratory.
Helicobacter infections usually are identified by nonculture methods. H. pylori can be presumptively identified in a gastric biopsy specimen by testing for the presence of a rapid urease reaction.Serologic testing is an important screening method for the diagnosis of H. pylori infection. It can also be diagnosed by faecal antigen detection, microscopic examination of stained gastric tissue, and DNA amplification tests.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 26
Correct
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A somatostatinoma is diagnosed in a 74-year-old patient who has recently developed diabetes mellitus, recurrent episodes of gallstones, and Steatorrhoea. She also has a tumour in the head of her pancreas.
Which of the following is the most likely effect of this tumour?Your Answer: Inhibit gastric acid secretion
Explanation:Somatostatin-producing cells present in the pyloric antrum, duodenum, and pancreatic islets are known as D-cells or delta-cells. Somatostatin inhibits gastric acid secretion by acting directly on acid-producing parietal cells in the stomach via a G-protein coupled receptor.
Somatostatin affects hormones in the following ways:
Inhibits the anterior pituitary’s secretion of growth hormone.
Inhibits the anterior pituitary’s secretion of thyroid-stimulating hormone.The secretion of various gastrointestinal hormones is inhibited (including gastrin, CCK, secretin, motilin, VIP and GIP)
Reduces the rate at which the stomach empties.
Inhibits the release of insulin and glucagon from the pancreas.The pancreas’ exocrine secretory activity is inhibited.
Somatostatin can also slow the digestive process by suppressing the production of hormones such gastrin, secretin, and histamine, which reduces gastric acid secretion.A somatostatinoma is a cancerous tumour of the endocrine pancreas’ D-cells, which make somatostatin. Somatostatin inhibits pancreatic and gastrointestinal hormones when levels are high. The following clinical characteristics are related with somatostatinomas:
Insulin secretion blockage causes diabetes mellitus.
Gallstones by inhibition of CCK and secretin Steatorrhoea via inhibition of CCK and secretinHypochlorhydria is caused by the suppression of gastrin, a hormone that increases gastric acid output regularly.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 27
Incorrect
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The sensory innervation of the oropharynx is provided by which of the following nerves:
Your Answer: Maxillary nerve
Correct Answer: Glossopharyngeal nerve
Explanation:Each subdivision of the pharynx has a different sensory innervation:the nasopharynx is innervated by the maxillary nervethe oropharynx is innervated by the glossopharyngeal nervethe laryngopharynx is innervated by the vagus nerve.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 28
Incorrect
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After collapsing in his nursing home, a 70-year-old man is brought into the ER. He is a known case of diabetes mellitus and is on medication for it. An RBS of 2.5 mmol/L (3.9-5.5 mmol/L) is recorded in the ER.
Out of the following, which medication for diabetes mellitus is MOST likely responsible for his hypoglycaemic episode?Your Answer: Acarbose
Correct Answer: Pioglitazone
Explanation:Pioglitazone is used to treat type 2 diabetes mellitus. It selectively stimulates the nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-γ) and to a lesser extent PPAR-α.
Of the medications mentioned in this question, only pioglitazone is a recognized cause of hypoglycaemia.
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This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 29
Incorrect
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A 58-year-old man presented to the emergency room complaining of a chest pain that has been going on for the past 12 hours. Upon further investigation, a troponin test was ordered and the results came back negative. He was given a discharge order from the emergency department.
Which of the following aspects of this test is considered the most significant in the decision made that it was safe to send the patient home?Your Answer: Sensitivity
Correct Answer: Likelihood ratio
Explanation:The Likelihood Ratio (LR) is the likelihood that a given test result would be expected in a patient with the target disorder compared to the likelihood that that same result would be expected in a patient without the target disorder.
The LR is used to assess how good a diagnostic test is and to help in selecting an appropriate diagnostic tests or sequence of tests. They have advantages over sensitivity and specificity because they are less likely to change with the prevalence of the disorder, they can be calculated for several levels of the symptom/sign or test, they can be used to combine the results of multiple diagnostic test and they can be used to calculate post-test probability for a target disorder.
A LR greater than 1 produces a post-test probability which is higher than the pre-test probability. An LR less than 1 produces a post-test probability which is lower than the pre-test probability. When the pre-test probability lies between 30 and 70 per cent, test results with a very high LR (say, above 10) rule in disease. An LR below 1 produces a post-test probability les than the pre-test probability. A very low LR (say, below 0.1) virtually rules out the chance that the patient has the disease.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 30
Incorrect
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A man working as a waiter cuts his arm on a glass while he was working. The palmaris longus muscle was damaged as a consequence of his injury.
Which of the following statements regarding the palmaris longus muscle is considered correct?Your Answer: It arises from the lateral epicondyle of the humerus
Correct Answer: It receives its blood supply from the ulnar artery
Explanation:The palmaris longus is a small, fusiform-shaped muscle located on the anterior forearm of the human upper extremity. The palmaris longus muscle is commonly present but may be absent in a small percentage of the population, ranging from 2.5% to 26% of individuals, depending on the studied population.
The palmaris longus belongs to the anterior forearm flexor group in the human upper extremity. The muscle attaches proximally to the medial humeral epicondyle and distally to the palmar aponeurosis and flexor retinaculum. The blood supply to the palmaris longus muscle is via the ulnar artery, a branch of the brachial artery in the human upper extremity.
The palmaris longus muscle receives its innervation via branches of the median nerve containing nerve roots C5-T1. Median nerve injury at or above the elbow joint (including brachial plexus and nerve root injury) can lead to deficits in the palmaris longus and other forearm flexor muscles, leading to weakened elbow flexion, wrist flexion, radial deviation, finger flexion, thumb opposition, flexion, and abduction, in addition to the loss of sensory function in the distribution of the median nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 31
Correct
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A 67-year-old woman complains of general malaise, nausea, and vomiting. She is perplexed and declares that everything 'looks yellow.' Her potassium level is 6.8 mmol/l, according to a blood test.
Which of the drugs listed below is most likely to be the cause of her symptoms?Your Answer: Digoxin
Explanation:Because digoxin has a narrow therapeutic index, it can cause toxicity both during long-term therapy and after an overdose. Even when the serum digoxin concentration is within the therapeutic range, it can happen.
Acute digoxin toxicity usually manifests itself within 2-4 hours of an overdose, with serum levels peaking around 6 hours after ingestion and life-threatening cardiovascular complications following 8-12 hours.
Chronic digoxin toxicity is most common in the elderly or those with impaired renal function, and it is often caused by a coexisting illness. The clinical signs and symptoms usually appear gradually over days to weeks.
The following are characteristics of digoxin toxicity:
Nausea and vomiting
Diarrhoea
Abdominal pain
Confusion
Tachyarrhythmias or bradyarrhythmias
Xanthopsia (yellow-green vision)
Hyperkalaemia (early sign of significant toxicity)Some precipitating factors are as follows:
Elderly patients
Renal failure
Myocardial ischaemia
Hypokalaemia
Hypomagnesaemia
Hypercalcaemia
Hypernatraemia
Acidosis
Hypothyroidism
Spironolactone
Amiodarone
Quinidine
Verapamil
Diltiazem -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 32
Incorrect
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Needle thoracentesis in a patient with a tension pneumothorax is performed at which anatomical landmark?
Your Answer: 2nd intercostal space mid-axillary line
Correct Answer: 4th or 5th intercostal space mid-axillary line
Explanation:Tension pneumothorax is a fatal disease causing acute and severe compromise of patients’ ventilation and circulation, in which case immediate decompression is necessary for better prognosis [6]. A previous study has shown that the incidence of tension pneumothorax varies from 0.2% to 1.7% in patients with prehospital trauma. Several trauma guidelines recommend needle thoracostomy as a life-saving intervention, with placement in the second intercostal space at the midclavicular line (second ICS-MCL), the fourth intercostal space at the anterior axillary line (fourth ICS-AAL), or the fifth intercostal space at the midaxillary line (fifth ICS-MAL) for tension pneumothorax in a prehospital environment.
In 2018, according to newly issued the Advanced Trauma Life Support (ATLS) guidelines, the fifth ICS-MAL was suggested as the preferred place, and an 8 cm needle rather than the common 5 cm needle was proved to increase success rate of adults’ decompression.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 33
Incorrect
-
Regarding autoregulation of local blood flow, which of the following statements is CORRECT:
Your Answer: In the myogenic mechanism, arterial vasodilation occurs in response to stretching of the vessel wall.
Correct Answer: An increase in blood flow dilutes locally produced vasodilating factors causing vasoconstriction.
Explanation:Autoregulation is the ability to maintain a constant blood flow despite variations in blood pressure (between 50 – 170 mmHg). It is particularly important in the brain, kidney and heart. There are two main methods contributing to autoregulation:
The myogenic mechanism involves arterial constriction in response to stretching of the vessel wall, probably due to activation of smooth muscle stretch-activated Ca2+channels and Ca2+entry. A reduction in pressure and stretch closes these channels, causing vasodilation.
The second mechanism of autoregulation is due to locally produced vasodilating factors; an increase in blood flow dilutes these factors causing vasoconstriction, whereas decreased blood flow has the opposite effect. -
This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 34
Incorrect
-
A patent has weakness of humeral flexion and extension. A CT scan reveals that he has suffered damage to the nerve that innervates pectoralis major.
Pectoralis major receives its innervation from which of the following nerves? Select ONE answer only.Your Answer: Nerve to subclavius and medial pectoral nerve
Correct Answer: Lateral and medial pectoral nerves
Explanation:Pectoralis major is a thick, fan-shaped muscle situated in the chest. It makes up the bulk of the chest musculature in the male and lies underneath the breast in the female. It overlies the thinner pectoralis minor muscle.
Superficial muscles of the chest and arm showing pectoralis major (from Gray’s Anatomy)
Pectoralis major has two heads; the clavicular head and the sternocostal head. The clavicular head originates from the anterior border and medial half of the clavicle. The sternocostal head originates from the anterior surface of the sternum, the superior six costal cartilages and the aponeurosis of the external oblique muscle. It inserts into the lateral lip of the bicipital groove of the humerus.
Pectoralis major receives dual innervation from the medial pectoral nerve and the lateral pectoral nerve.
Its main actions are as follows:
Flexes humerus (clavicular head)
Extends humerus (sternocostal head)
Adducts and medially rotates the humerus
Draws scapula anteriorly and inferiorly -
This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 35
Incorrect
-
Herpes simplex encephalitis has a predilection for which of the following sites:
Your Answer: Occipital lobe
Correct Answer: Temporal lobe
Explanation:Herpes simplex virus is the most common cause of infective encephalitis and has a predilection for the temporal lobes. Herpes simplex is transmitted through direct contact. It invades skin locally producing skin vesicles by its cytolytic activity.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 36
Incorrect
-
A 45-year-old woman presents with persistent palpitations for the past two days. She has a good haemodynamic balance. An ECG is performed, which reveals that she has atrial flutter. The patient is examined by a cardiology registrar, who recommends using a 'rate control' strategy while she waits for cardioversion.
Which of the drugs listed below is the best fit for this strategy?Your Answer: Adenosine
Correct Answer: Bisoprolol
Explanation:In atrial flutter, ventricular rate control is usually used as a stopgap measure until sinus rhythm can be restored. A beta-blocker (such as bisoprolol), diltiazem, or verapamil can be used to lower the heart rate.
Electrical cardioversion, pharmacological cardioversion, or catheter ablation can all be used to restore sinus rhythm. Cardioversion should not be attempted until the patient has been fully anticoagulated for at least three weeks if the duration of atrial flutter is unknown or has lasted for more than 48 hours. Emergency electrical cardioversion is the treatment of choice when there is an acute presentation with haemodynamic compromise. For the treatment of recurrent atrial flutter, catheter ablation is preferred.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 37
Incorrect
-
Regarding box and whisker plots, which of the following statements is true?
Your Answer: They are used to display qualitative variables
Correct Answer: 25% of the values lie below the lower quartile
Explanation:A box and whisker plot is defined as a graphical method of displaying variation in a set of data. In most cases, a histogram analysis provides a sufficient display, but a box and whisker plot can provide additional detail while allowing multiple sets of data to be displayed in the same graph.
The procedure to develop a box and whisker plot comes from the five statistics below:
(1) Minimum value: The smallest value in the data set
(2) Second quartile: The value below which the lower 25% of the data are contained
(3) Median value: The middle number in a range of numbers
(4) Third quartile: The value above which the upper 25% of the data are contained
(5) Maximum value: The largest value in the data set
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This question is part of the following fields:
- Evidence Based Medicine
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Question 38
Correct
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Epigastric pain and haematemesis present in a 67-year-old man. In the emergency room, he is stabilised and referred to the on-call medical team. He has been scheduled for an endoscopy in the morning due to a suspected peptic ulcer. Before transferring him to the ward, you consider giving him a proton pump inhibitor (PPI).
Which of the following doses and routes are the best?Your Answer: A PPI should not be prescribed
Explanation:PPIs should not be used prior to endoscopic therapy when an early endoscopic examination is performed within 24 hours of admission, according to current recommendations.
High-dose PPI therapy reduces the risk of rebleeding and surgery after endoscopic treatment of severe peptic ulcer bleeding. Both oral and intravenous PPIs produce similar results, and there is no discernible benefit to using the intravenous formulation in patients who can tolerate oral medication. -
This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 39
Correct
-
All of the following cause bronchodilation, EXCEPT for:
Your Answer: Stimulation of irritant receptors
Explanation:Factors causing bronchodilation: Via beta2-adrenoceptors
Sympathetic stimulation:
Adrenaline (epinephrine)
Beta2-adrenergic agonists e.g. salbutamol
Anticholinergic and muscarinic antagonists e.g. ipratropium -
This question is part of the following fields:
- Physiology
- Respiratory
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Question 40
Incorrect
-
The following statements about cross-sectional studies are true EXCEPT?
Your Answer: They do not differentiate between cause and effect
Correct Answer: They can be used to determine the relative risk of a condition
Explanation:The UK national census is an example of a cross-sectional study.
Cross-sectional studies can be used to assess the prevalence of a condition, and support or refute inferences of cause and effect.
Cross-sectional studies are observations of the frequency and characteristics of a disease in a given population at one particular point in time.
Cross-sectional studies do not differentiate between cause and effect and also do not establish the sequence of events.
Cross-sectional studies cannot be used to calculate the relative risk of a condition.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 41
Correct
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After a work-related accident, a 33-year old male is taken to the emergency room with difficulty in adduction and flexion of his left arm at the glenohumeral joint. The attending physician is suspects involvement of the coracobrachialis muscle.
The nerve injured in the case above is?Your Answer: The musculocutaneous nerve
Explanation:The coracobrachialis muscle is innervated by the musculocutaneous nerve (C5-C7) a branch of the lateral cord of the brachial plexus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 42
Incorrect
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Streptococcus pyogenes is commonly implicated in all of the following infective diseases EXCEPT for:
Your Answer: Quinsy
Correct Answer: Gas gangrene
Explanation:Gas gangrene is a life-threatening infection caused by toxin-producing Clostridium species, primarily Clostridium perfringens, and characterised by rapidly progressive muscle necrosis, gas production and sepsis.
Gas gangrene is not a notifiable disease. -
This question is part of the following fields:
- Microbiology
- Pathogens
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Question 43
Incorrect
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A 45-year-old obese patient goes to the emergency department with a fever and significant right upper quadrant pain. The pain radiates to her right shoulder tip. Murphy's sign is positive and acute cholecystitis is diagnosed. The pain referred to the shoulder tip is caused by one of the following nerves:
Your Answer: Intercostal nerves
Correct Answer: Phrenic nerve
Explanation:Gallbladder inflammation can cause pain in the right upper quadrant and right shoulder, which is caused by irritation of the diaphragmatic peritoneum. Pain from areas supplied by the phrenic nerve is often referred to other somatic regions served by spinal nerves C3-C5.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 44
Incorrect
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The least likely feature expected to be seen in a lesion of the frontal lobe is which of the following?
Your Answer: Personality change
Correct Answer: Loss of two-point discrimination
Explanation:Lesions in different areas give rise to different symptoms.
Lesions of the parietal lobe give rise to loss of two-point discrimination.
Lesions to Broca’s area give rise to expressive dysphasia results from damage
Lesions to the primary motor cortex give rise to contralateral weakness of the face and arm.
Lesions to the prefrontal cortex give rise to personality change.
Lesions to the frontal eye field give rise to conjugate eye deviation towards side of lesion. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 45
Incorrect
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A 54-year-old woman presents with polyuria and polydipsia. She is known to suffer from bipolar disorder, which has been well controlled by the use of lithium for many years.
What is the SINGLE most likely diagnosis?Your Answer: Type 1 diabetes mellitus
Correct Answer: Nephrogenic diabetes insipidus
Explanation:Diabetes insipidus is the inability to produce concentrated urine. It is characterised by the presence of excessive thirst, polyuria and polydipsia. There are two distinct types of diabetes insipidus:
Cranial (central) diabetes insipidus and;
Nephrogenic diabetes insipidus
Cranial diabetes insipidus is caused by a deficiency of vasopressin (anti-diuretic hormone). Patients with cranial diabetes insipidus can have a urine output as high as 10-15 litres per 24 hours, but adequate fluid intake allows most patients to maintain normonatraemia. 30% of cases are idiopathic, and a further 30% are secondary to head injuries. Other causes include neurosurgery, brain tumours, meningitis, granulomatous disease (e.g. sarcoidosis) and drugs, such as naloxone and phenytoin. A very rare inherited form also exists that is associated with diabetes mellitus, optic atrophy, nerve deafness and bladder atonia.
Nephrogenic diabetes insipidus is caused by renal resistance to the action of vasopressin. As with cranial diabetes insipidus, urine output is markedly elevated. Serum sodium levels can be maintained by secondary polydipsia or can be elevated. Causes of nephrogenic diabetes insipidus include chronic renal disease, metabolic disorders (e.g. hypercalcaemia and hypokalaemia) and drugs, including long-term lithium usage and demeclocycline.
In view of the history of long-term lithium use, in this case, nephrogenic diabetes insipidus is the most likely diagnosis. -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 46
Incorrect
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A tumour is discovered behind the pectinate line during an examination of a 72-year-old patient with rectal bleeding. Which of the following is the lymphatic drainage of the pectinate line?
Your Answer: Deep inguinal nodes
Correct Answer: Superficial inguinal nodes
Explanation:The pectinate line is known as the watershed line because it divides the anal canal into two sections. Below the pectinate line, lymphatic drainage drains to the superficial inguinal lymph nodes.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 47
Correct
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Regarding amoxicillin, which of the following statements is INCORRECT:
Your Answer: It is used first line for bacterial tonsillitis.
Explanation:Amoxicillin is a derivative of ampicillin and has a similar antibacterial spectrum. It is better absorbed than ampicillin when given orally, producing higher plasma and tissue concentrations; unlike ampicillin, absorption is not affected by the presence of food in the stomach.
The adverse effects of amoxicillin are mainly gastrointestinal and mild and include nausea, vomiting and diarrhoea. Amoxicillin is used first line for low to moderate severity community acquired pneumonia, exacerbations of chronic bronchitis, for acute otitis media, for acute sinusitis, for oral infections/dental abscess, for Listeria meningitis (in combination with another antibiotic), for infective endocarditis (in combination with another antibiotic) and for H. Pylori eradication (in combination with metronidazole/clarithromycin and a PPI).
Penicillin V is used first line for bacterial tonsillitis; amoxicillin should be avoided in blind treatment of a sore throat as there is a high risk of a rash if glandular fever is present.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 48
Incorrect
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ACE inhibitors are indicated for all of the following EXCEPT for:
Your Answer: Heart failure
Correct Answer: Angina
Explanation:ACE inhibitors have many uses and are generally well tolerated. They are indicated for:
- Heart failure
- Hypertension
- Diabetic nephropathy
- Secondary prevention of cardiovascular events
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 49
Incorrect
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A patient presents with a gastrointestinal infection. Which of the following microbes attaches to gut mucosa via a specialised sucking disc:
Your Answer: Campylobacter jejuni
Correct Answer: Giardia lamblia
Explanation:Giardia lambliainfection occurs through the ingestion of dormant microbial cysts in contaminated water, food or via faceo-oral transmission via poor hygiene.
Following ingestion of the cysts, the trophozoite emerges to an active state of feeding and motility. After the feeding stage they undergo asexual replication through longitudinal binary fission.
They attach to the intestinal wall via a specialised sucking disc. The mechanism for diarrhoea in giardiasis remains unknown but could possibly be due to direct cytotoxicity.
Giardial trophozoites and cysts pass through the digestive system in the faeces and are excreted. While the trophozoites may be found in the faeces, only the cysts are adapted for long-term survival outside the host. -
This question is part of the following fields:
- Microbiology
- Principles
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Question 50
Correct
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Question 51
Incorrect
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At the start of the cardiac cycle, towards the end of diastole, all of the following statements are true EXCEPT for:
Your Answer: The AV valves are open.
Correct Answer: The semilunar valves are open.
Explanation:At the start of the cardiac cycle, towards the end of diastole, the whole of the heart is relaxed. The atrioventricular (AV) valves are open because the atrial pressure is still slightly greater than the ventricular pressure. The semilunar valves are closed, as the pressure in the pulmonary artery and aorta is greater than the ventricular pressures. The cycle starts when the sinoatrial node (SAN) initiates atrial systole.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 52
Correct
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Which of the following best describes the main sites of constriction of the ureters:
Your Answer: At the ureteropelvic junction, at the pelvic brim and where the ureters enter the bladder
Explanation:At three points along their course, the ureters are constricted denoting the most likely areas for renal calculi to lodge:the first point is at the ureteropelvic junction (where the renal pelvis becomes continuous with the ureter)the second point is where the ureter crosses the common iliac vessels at the pelvic brimthe third point is at the vesicoureteric junction (where the ureter enters the wall of the bladder)
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 53
Incorrect
-
Regarding forest plots, which of the following is the purpose of this graph?
Your Answer: To compare survival times amongst patients receiving different treatments
Correct Answer: To graphically display the relative strength of multiple studies attempting to answer the same question
Explanation:The results of meta-analysis are often displayed graphically in a forest plot. A properly constructed forest plot is the most effective way to graphically display the relative strength of multiple studies attempting to answer the same question. A typical meta-analysis consists of three main objectives that include estimation of effect sizes from individual studies and a pooled summary estimate with their confidence intervals (CIs), heterogeneity among the studies, and any publication bias. The forest plot illustrates the first two of these objectives. Forest plots visualize the effect measure and CI of individual studies, which provide the raw data for the meta-analysis, as well the pooled-effect measure and CI. The individual studies also can be grouped in the forest plot by some of their characteristics for ease of interpretation such as by study size or year of publication. When comparing the outcomes between an intervention and a control group, dichotomous outcome variables are expressed as ratios (i.e. odds ratios, ORs or risk ratios, RRs), while for continuous outcomes, a weighted mean difference is reported.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 54
Incorrect
-
Which of the following laboratory findings is NOT typical of Hodgkin lymphoma:
Your Answer: Raised LDH
Correct Answer: Basophilia
Explanation:Features may include:Normochromic normocytic anaemia is most common; bone marrow failure involvement is unusual in early disease, but if it occurs bone marrow failure may develop with leucoerythroblastic anaemiaOne-third of patients have a neutrophilia; eosinophilia is frequentAdvanced disease is associated with lymphopenia and loss of cell-mediated immunityPlatelet count is normal or increased in early disease and reduced in later stagesESR and CRP are usually raised (ESR is useful in monitoring disease progress)Serum LDH is raised initially in 30-40% of casesDiagnosis is made by histological examination of an excised lymph nodeThe distinctive multinucleate polypoid RS cell is central to the diagnosis of the four classic types of HL (95% of cases)
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This question is part of the following fields:
- Haematology
- Pathology
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Question 55
Incorrect
-
A 26-year old female comes to the Emergency Room with complaints of bloody stools. She reports that prior to the passage of bloody stools, she experienced a sharp pain during defecation. Medical history reveals that she has been experiencing constipation for the past 2 weeks. After completing her medical history and physical examination, the attending physician gives an initial diagnosis of an anal fissure.
Which of the following nerves transmit painful sensation from the anus, resulting in the pain associated with anal fissure?Your Answer: Superior rectal nerve
Correct Answer: Inferior rectal nerve
Explanation:A fissure in ano is a tear in the anoderm distal to the dentate line. The pathophysiology of anal fissure is thought to be related to trauma from either the passage of hard stool or prolonged diarrhoea. A tear in the anoderm causes spasm of the internal anal sphincter, which results in pain, increased tearing, and decreased blood supply to the anoderm. The site of the anal fissure in the sensitive lower half of the anal canal, which is innervated by the inferior rectal nerve, results in reflex spasm of the external anal sphincter, aggravating the condition. Because of the intense pain, anal fissures may have to be examined under local anaesthesia.
The inferior rectal nerve is a branch of the pudendal nerve. This nerve runs medially across the ischiorectal fossa and supplies the external anal sphincter, the mucous membrane of the lower half of the anal canal, and the perianal skin.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 56
Incorrect
-
When treating diabetic ketoacidosis (DKA), glucose should be given together with insulin as soon as the blood glucose concentration falls below 14 mmol/L in the form of:
Your Answer: 5% glucose intravenous infusion at a rate of 250 mL/hour
Correct Answer: 10% glucose intravenous infusion at a rate of 125 mL/hour
Explanation:In addition to the sodium chloride 0.9 percent infusion, glucose 10% should be given intravenously (into a large vein with a large-gauge needle) at a rate of 125 mL/hour once blood glucose concentration falls below 14 mmol/litre.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 57
Incorrect
-
Antidiuretic hormone (ADH) levels are found to be increased in a young lady with unexplained hyponatraemia.
In a healthy patient under normal circumstances, in which of the following conditions would ADH not be released?Your Answer: Increased circulating Angiotensin II
Correct Answer: Increased alcohol intake
Explanation:Antidiuretic hormone (ADH) is produced in the hypothalamus’s supraoptic nucleus and then released into the blood via axonal projections from the hypothalamus to the posterior pituitary.
It is carried down axonal extensions from the hypothalamus (the neurohypophysial capillaries) to the posterior pituitary, where it is kept until it is released, after being synthesized in the hypothalamus.
The secretion of ADH from the posterior pituitary is regulated by numerous mechanisms:
Increased plasma osmolality: Osmoreceptors in the hypothalamus detect an increase in osmolality and trigger ADH release.Hypovolaemia causes a drop in atrial pressure, which stretch receptors in the atrial walls and big veins detect (cardiopulmonary baroreceptors). ADH release is generally inhibited by atrial receptor firing, but when the atrial receptors are stretched, the firing reduces and ADH release is promoted.
Hypotension causes baroreceptor firing to diminish, resulting in increased sympathetic activity and ADH release.
An increase in angiotensin II stimulates angiotensin II receptors in the hypothalamus, causing ADH production to increase.Nicotine, Sleep, Fright, and Exercise are some of the other elements that might cause ADH to be released.
Alcohol (which partly explains the diuretic impact of alcohol) and elevated levels of ANP/BNP limit ADH release. -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 58
Incorrect
-
Regarding an avulsion fracture, a sudden contraction of which muscle may lead to fracture of the head of the fibula?
Your Answer: Semimembranosus
Correct Answer: Biceps femoris
Explanation:Avulsion fractures of the fibular head are rare and are so-called the arcuate signal. The “arcuate signal” is used to describe an avulsed bone fragment related to the insertion site of the tendon of the biceps femoris associated with the arcuate complex, which consists of the fabellofibular, popliteofibular, and arcuate ligaments. Such lesions are typically observed in direct trauma to the knee with excessive varus and internal rotation forces or indirect trauma with the same direction of the force.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 59
Incorrect
-
Regarding atracurium, which of the following statements is CORRECT:
Your Answer: Atracurium should be avoided in renal impairment.
Correct Answer: Effects such as flushing, tachycardia and hypotension can occur due to significant histamine release.
Explanation:Cardiovascular effects such as flushing, tachycardia, hypotension and bronchospasm are associated with significant histamine release; histamine release can be minimised by administering slowly or in divided doses over at least 1 minute. Atracurium undergoes non-enzymatic metabolism which is independent of liver and kidney function, thus allowing its use in patients with hepatic or renal impairment. Atracurium has no sedative or analgesic effects. All non-depolarising drugs should be used with care in patients suspected to be suffering with myasthenia gravis or myasthenic syndrome, as patients with these conditions are extremely sensitive to their effects and may require a reduction in dose.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 60
Incorrect
-
Which of the following globin chains makes up normal adult haemoglobin (HbA)?
Your Answer: Two alpha chains and two delta chains
Correct Answer: Two alpha and two beta chains
Explanation:Total adult haemoglobin comprises about 96 – 98 % of normal adult haemoglobin (HbA). It consists of two alpha (α) and two beta (β) globin chains.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 61
Incorrect
-
A patient with abdominal pain, vomiting and bloody diarrhoea develops a low platelet count and deranged renal function. A diagnosis of haemolytic uraemic syndrome is made.
Which of the following organisms is a recognised cause of haemolytic uraemic syndrome? Select ONE answer only.Your Answer: Streptococcus pyogenes
Correct Answer: Escherichia coli
Explanation:E.Colistrain 0157 causes enterohaemorrhagic diarrhoea and can be followed by haemolytic uraemic syndrome (renal failure, haemolytic anaemia and thrombocytopenia).
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 62
Incorrect
-
You review a sick patient in resus who has been prescribed mannitol as part of his treatment protocol.
Which SINGLE statement regarding mannitol is true?Your Answer: It is not filtered at the glomerulus
Correct Answer: It is irritant to veins and causes phlebitis
Explanation:Mannitol is a low molecular weight compound and is therefore freely filtered at the glomerulus and is not reabsorbed. It, therefore, increases the osmolality of the glomerular filtrate and tubular fluid, increasing urinary volume by an osmotic effect. It also does not cross the blood-brain barrier (BBB).
Mannitol is primarily used to reduce the pressure and volume of cerebrospinal fluid (CSF). It decreases the volume of CSF by:
Decreasing the rate of CSF formation,and;
Withdrawing extracellular fluid from the brain across the BBB
Other uses of mannitol include:
Short-term management of glaucoma
Treatment of rhabdomyolysis
Preserve renal function in peri-operative jaundiced patients
To initiate diuresis in transplanted kidneys
Bowel preparation prior to colorectal procedures
The recommended dose of mannitol for the reduction of CSF pressure/cerebral oedema is 0.25-2g/kg as an intravenous infusion over 30-60 minutes. This can be repeated 1-2 times after 4-8 hours if needed.
Circulatory overload and rebound increases in intracranial pressure may occur following the use of mannitol. It is irritant to tissues and veins and can cause inflammation and phlebitis.
Mannitol causes an expansion of the extracellular fluid space, which may worsen congestive cardiac failure. Contraindications to the use of mannitol include:
Anuria
Intracranial bleeding (except during craniotomy)
Severe cardiac failure
Severe dehydration
Severe pulmonary oedema -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 63
Incorrect
-
The tetanus vaccination contains inactivated tetanus toxoid, which induces the body to produce protective antibodies. How do these antibodies protect the body from tetanus?
Your Answer: Bind C. tetani cells and activate complement
Correct Answer: Neutralise the protein exotoxin of C. tetani
Explanation:C. Tetanospasmin, an exotoxin produced by tetani, is responsible for the neurotoxic consequences of tetanus.
The tetanus vaccination contains inactivated tetanus toxoid, which induces the body to produce protective antibodies that neutralize the tetanus toxin.
It induces active immunization against Clostridium tetani exotoxin via toxoid-induced Ab generation.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 64
Incorrect
-
On his stool culture, a patient with a diarrhoeal illness grows Escherichia coli.
What SINGLE statement about Escherichia coli is true?
Your Answer: It is a coccus
Correct Answer: Most serotypes are harmless
Explanation:Escherichia coli is a Gram-negative, non-spore forming, facultative anaerobic, rod-shaped bacterium.
Although some can cause serious food poisoning, most serotypes are harmless.
Escherichia coli is transmitted via the faeco-oral route.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 65
Incorrect
-
Antispasmodic drugs are primarily indicated in which of the following conditions:
Your Answer: Urinary retention
Correct Answer: Irritable bowel syndrome
Explanation:Antispasmodics, such as antimuscarinics, may be used in the management of irritable bowel syndrome. Other antispasmodics used include direct-acting smooth muscle relaxants such as mebeverine, alverine, and peppermint oil. Antispasmodics are contraindicated in bowel obstruction and severe inflammatory bowel disease. Antispasmodics are occasionally of value in treating abdominal cramp associated with diarrhoea but they should not be used for primary treatment. Antispasmodics should be avoided in young children with gastroenteritis because they are rarely effective and have troublesome side effects. Antimuscarinics are contraindicated in urinary retention.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 66
Incorrect
-
Which of the following conditions require IV Lidocaine administration?
Your Answer: Chemical cardioversion of atrial fibrillation
Correct Answer: Refractory ventricular fibrillation in cardiac arrest
Explanation:IV Lidocaine is indicated in Ventricular Arrhythmias or Pulseless Ventricular Tachycardia (after defibrillation, attempted CPR, and vasopressor administration)
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 67
Incorrect
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A 6-year-old girl is brought into the paediatric emergency room by her mother in a state of high-grade fever and extreme irritability. She is also reluctant to urinate as it is associated with lower abdominal pain and stinging. She has no history of any UTIs requiring antibiotics in the past 12 months.
The urine sensitivity test report is still unavailable. A clean catch urine sample is taken for urine dipstick, which reveals the presence of blood, protein, leukocytes and nitrites. Fresh blood tests were sent, and her estimated GFR is calculated to be 40 ml/minute.
Out of the following, which antibiotic is most appropriate to be prescribed to this patient?Your Answer: Ciprofloxacin
Correct Answer: Trimethoprim
Explanation:The NICE guidelines for children and young people under 16 years lower UTIs are:
1. Get a urine sample before antibiotics are taken, and do a dipstick test OR send for culture and susceptibility
2. Assess and manage children under 5 with lower UTI with fever as recommended in the NICE guideline on fever in under 5s.
3. Prescribe an immediate antibiotic prescription and take into account the previous urine culture and susceptibility results, previous antibiotic use, which may have led to resistant bacteria
4. If urine culture and susceptibility report is sent
– Review the choice of antibiotic when the results are available AND
– change the antibiotic according to susceptibility results if the bacteria are resistant and symptoms are not improving, using a narrow-spectrum antibiotic wherever possibleThe choice of antibiotics for non-pregnant young people under 16 years with lower UTI is summarised below:
1. Children under 3 months:
– Refer to paediatric specialist and treat with intravenous antibiotic in line with NICE guideline on fever in under 5s
2. Children over 3 months:
– First-choice
Nitrofurantoin – if eGFR >45 ml/minute
Trimethoprim – (if low risk of resistance*)
– Second-choice (no improvement in lower UTI symptoms on first-choice for at least 48 hours, or when first-choice not suitable)
Nitrofurantoin – if eGFR >45 ml/minute and not used as first-choice
Amoxicillin (only if culture results available and susceptible)
Cefalexin -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 68
Incorrect
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The least likely feature of anaemia is:
Your Answer: Flow murmurs
Correct Answer: Narrow pulse pressure
Explanation:Non-specific signs of anaemia include:
1. pallor of mucous membranes or nail beds (if Hb < 90 g/L),
2. tachycardia
3. bounding pulse
4. wide pulse pressure
5. flow murmurs
6. cardiomegaly
7. signs of congestive cardiac failure (in severe cases) -
This question is part of the following fields:
- Haematology
- Pathology
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Question 69
Incorrect
-
Regarding likelihood ratios, which of the following statements is INCORRECT:
Your Answer: Negative likelihood ratio = (1 - sensitivity)/specificity
Correct Answer: Likelihood ratios, like predictive values, are affected by the prevalence of the disease in the population.
Explanation:A likelihood ratio is a measure of the diagnostic value of a test. Likelihood ratios show how many times more likely patients with a disease are to have a particular test result than patients without the disease. Likelihood ratios are more useful than predictive values because they are calculated from sensitivity and specificity and therefore remain constant even when the prevalence of the disorder changes.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 70
Incorrect
-
The most common type of adult leukaemia is chronic lymphocytic leukaemia (CLL). It develops as a result of lymphocyte clonal proliferation. Which of the following statements about CLL is CORRECT?
Your Answer: > 90% of cases are of T-cell lineage
Correct Answer: It is most commonly discovered as an incidental finding
Explanation:CLL (chronic lymphocytic leukaemia) is the most common type of chronic lymphoid leukaemia, with a peak incidence between the ages of 60 and 80. It is the most common type of leukaemia in Europe and the United States, but it is less common elsewhere.
The CLL tumour cell is a mature B-cell with low immunoglobulin surface expression (IgM or IgD). The average age at diagnosis is 72 years, with only 15% of cases occurring before the age of 50.
The male-to-female ratio is about 2:1. Over 80% of cases are identified by the results of a routine blood test, which is usually performed for another reason.
Lymphocytic anaemia, thrombocytopenia, and normochromic normocytic anaemia are common laboratory findings. Aspiration of bone marrow reveals up to 95% lymphocytic replacement of normal marrow elements.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 71
Incorrect
-
Which of the following is a physiological function that is mediated by a hormone released by the posterior pituitary:
Your Answer: Increase in basal metabolic rate
Correct Answer: Water retention
Explanation:Antidiuretic hormone (ADH), released by the posterior pituitary, acts on the kidneys to increase water permeability in the distal nephron allowing greater water reabsorption and concentration of urine. Prolactin, from the anterior pituitary, is responsible for milk production. The thyroid hormones, from the thyroid gland, are responsible for an increase in basal metabolic rate (stimulated by TSH from the anterior pituitary). FSH/LH, from the anterior pituitary, are responsible for maturation of egg and sperm. Calcitonin, from the thyroid gland, is responsible for decreasing calcium levels.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 72
Incorrect
-
A paediatric patient comes to the emergency room with complaints of right lower quadrant pain. The attending physician is considering appendicitis. Inside the operating room, the surgeon asks the medical student to locate the McBurney's point prior to the first incision.
Which of the following is the surface anatomy of the McBurney's point?Your Answer: Two-thirds of the distance from the posterior superior iliac spine to the umbilicus
Correct Answer: One-third of the distance from the anterior superior iliac spine to the umbilicus
Explanation:Inflammation of the appendix is a significant public health problem with a lifetime incidence of 8.6% in men and 6.7% in women, with the highest incidence occurring in the second and third decade of life. While the rate of appendectomy in developed countries has decreased over the last several decades, it remains one of the most frequent emergent abdominal operations. Appendicitis can often result in anorexia, nausea, vomiting, and fever.
McBurney’s point, which is found one-third of the distance between the anterior superior iliac spine and the umbilicus, is often the point of maximal tenderness in a patient with an anatomically normal appendix. A McBurney’s incision is chiefly used for cecostomy and appendectomy. It gives a limited exposure only, and should any doubt arise about the diagnosis, an infraumbilical right paramedian incision should be used instead.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 73
Incorrect
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A p value < 0.05 obtained from a study with a significance level (α) of 0.05, means all of the following, EXCEPT:
Your Answer: the alternative hypothesis is accepted.
Correct Answer: the result is clinically significant.
Explanation:A p value < 0.05:is statistically significantmeans that the probability of obtaining a given result by chance is less than 1 in 20means the null hypothesis is rejectedmeans there is evidence of an association between a variable and an outcomeNote that this does not tell us whether the result is clinically significant.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 74
Incorrect
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The only statement that is correct regarding diffusion is which of the following?
Your Answer: Passive diffusion refers to movement from an area of low concentration to an area of high concentration.
Correct Answer: The permeability of a membrane is related to the membrane thickness and composition.
Explanation:Passive diffusion is a process that describes the movement down a concentration gradient. This process accounts for movement across small distances like within the cytosol or across membranes. Factors that affect the diffusion of a substance across a membrane are the permeability (p) of the membrane, a difference in concentration across the membrane and the membrane area over which diffusion occurs. The membrane thickness and composition, and the diffusion coefficient of the substance also affects the permeability. Fick’s law describes the rate of diffusion of a substance within a solution, which can be modified to describe the rate of diffusion across a membrane.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 75
Incorrect
-
A young male has presented to the Emergency Department with a sudden onset of severe palpitations, shortness of breath, and chest pain. A 12-lead ECG is recorded, and it shows a narrow complex tachycardia that points to a diagnosis of supraventricular tachycardia.
Vagal manoeuvres are attempted but are unsuccessful in eliminating the arrhythmia. The next action plan is to use a drug to revert to sinus rhythm.
Out of the following, which is the first-line treatment for supraventricular tachycardia?Your Answer: Flecainide
Correct Answer: Adenosine
Explanation:Paroxysmal supraventricular tachycardia is an intermittent tachycardia (HR > 100 bpm) and has the following characteristics:
1. Sudden onset/offset (Contrast with sinus tachycardia)
2. Electrical activity originates above the ventricle (Contrast with ventricular tachycardia)
3. Produces narrow QRS complex (<120ms) The most common cause of PSVT is Atrioventricular nodal re-entrant tachycardia (AVNRT), most common in young women with a mean age onset of 32 years old. There are recurrent episodes of palpitations, and most of the episodes spontaneously. Sometimes, some vagal manoeuvres are required:
1. Valsalva manoeuvre
2. immersing the face in ice-cold water
3. carotid sinus massage.If PSVT keeps persisting or is causing severe symptoms, the treatment of choice is intravenous adenosine. The patient’s ECG should be continuously monitored throughout the treatment.
The recommended doses in adults are as follows:
– Initial dose of adenosine is 6 mg by rapid IV bolus
– If unsuccessful, give another dose of adenosine 12 mg by rapid IV bolus
– If unsuccessful, give a further dose of adenosine 12 mg by rapid IV bolus
The latest ALS guidelines advocate 18 mg for the third dose, whereas the BNF/NICE guidelines advocate 12 mg.If adenosine fails or is contraindicated, intravenous verapamil can be used as an alternative, but it should be avoided in patients recently treated with beta-blockers.
Synchronized electrical cardioversion will be necessary with signs of hemodynamic instability or if drug treatment has failed to restore sinus rhythm.
Recurrent episodes of paroxysmal supraventricular tachycardia can be treated by catheter ablation or prevented with drugs such as flecainide, sotalol, diltiazem, or verapamil. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 76
Correct
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A 20-year-old patient had sustained a supracondylar fracture due to falling from a skateboard. The frequency of acute nerve injuries accompanying supracondylar humeral fractures ranges from 10 to 20%. The most common complication is injury to which nerve?
Your Answer: Median nerve
Explanation:According to various studies, the frequency of acute nerve damage associated with supracondylar humeral fractures in children ranges from 10% to 20%.
Median nerve injury and anterior interosseous nerve injury are the most common consequences.
Damage to this nerve indicated weakening or abnormal extension of the index finger’s distal interphalangeal joint and the thumb’s interphalangeal joint. The absence of sensibility is a distinguishing attribute.
A surgical neck humerus fracture may cause injury to the axillary nerve. A midshaft humerus fracture might cause injury to the radial nerve. A medial epicondylar fracture might cause injury to the ulnar nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 77
Incorrect
-
Innate, or non-specific, immunity is the immune system we are born with.
Which of the following is NOT an example of innate immunity? Select ONE answer only.Your Answer: Enzymes in tears
Correct Answer: T-lymphocytes
Explanation:Innate, or non-specific, immunity is the immune system we are born with.
There are three aspects of innate immunity:
1. Anatomical barriers, such as:
The cough reflex
Enzymes in tears and skin oils
Mucus – which traps bacteria and small particles
Skin
Stomach acid
2. Humoral barriers, such as:
The complement system
Interleukin-1
3. Cellular barriers, such as:
Neutrophils
Macrophages
Dendritic cells
Natural killer cells
Antibody production is part of the specific, or inducible immune response. T-lymphocytesare responsible for the cell mediated immune response which is part of specific, or inducible immunity. -
This question is part of the following fields:
- General Pathology
- Pathology
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Question 78
Incorrect
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A 19-year-old with a longstanding history of asthma presents to the ED with worsening symptoms of cough and wheeze and a peak expiratory flow rate (PEFR) measurement is taken.
Which statement concerning PEFR is true?Your Answer: PEFR is a useful measure in restrictive airways disease
Correct Answer: PEFR is dependent upon the patient's height
Explanation:The maximum flow rate generated during a forceful exhalation, after maximal inspiration is the peak expiratory flow rate (PEFR).
PEFR is dependent upon initial lung volume. It is, therefore, dependant on patient’s age, sex and height.
PEFR is dependent on voluntary effort and muscular strength of the patient.
PEFR is decreased with increasing airway resistance, e.g. in asthma, and it correlates well with the forced expiratory volume in one second (FEV1) value measured in spirometry. This correlation decreases in patients with asthma as airflow decreases.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 79
Correct
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Regarding bronchiolitis, which of the following statements is CORRECT:
Your Answer: Chest x-ray may show hyperinflation and increased peribronchial markings.
Explanation:Acute bronchiolitis is caused most commonly by respiratory syncytial virus, occurring mostly in children aged 6 months to 2 years. Children with bronchiolitis are febrile and tachypnoeic with a dry cough and difficulty feeding. Examination may reveal chest hyperinflation, respiratory distress, wheezing and fine end-inspiratory crepitations. Chest x-ray may show hyperinflation and increased peribronchial markings (although CXR should only performed if there is diagnostic uncertainty or an atypical course). Treatment is usually supportive, aerosolized ribavirin is reserved for severely ill or immunocompromised patients.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 80
Incorrect
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A 44 year old woman sustains an injury to the median nerve at the elbow after falling awkwardly. Which of the following clinical features are you LEAST likely to see on examination:
Your Answer: Weakness of wrist flexion
Correct Answer: Loss of flexion of the medial two digits
Explanation:Flexion of the index and middle fingers at the IPJs is lost due to paralysis of the flexor digitorum superficialis and the lateral half of the flexor digitorum profundus. Flexion of the MCPJs of the index and middle fingers are lost due to paralysis of the lateral two lumbrical muscles. Flexion of the ring and little fingers are preserved as these are supported by the medial half of the flexor digitorum profundus and the medial two lumbrical muscles, innervated by the ulnar nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 81
Incorrect
-
A patient presents with a cough, productive of green sputum and fever. He was commenced on antibiotics 4 days earlier, but his condition has worsened. There is a documented history of penicillin allergy, and the GP prescribed erythromycin.
Erythromycin exert its pharmacological effect by binding to?
Your Answer: DNA gyrase
Correct Answer: The 50S subunit of the bacterial ribosome
Explanation:Macrolides are bacteriostatic antibiotics. They act by binding to the 50S subunit of the bacterial ribosome and inhibit translocation, therefore, inhibiting protein synthesis.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 82
Correct
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You examine a 78-year-old man who has been diagnosed with chronic lymphocytic leukaemia (CLL).
What is the MAIN contributory factor in this condition's immunodeficiency?Your Answer: Hypogammaglobulinemia
Explanation:Immunodeficiency is present in all patients with chronic lymphocytic leukaemia (CLL), though it is often mild and not clinically significant. Infections are the leading cause of death in 25-50 percent of CLL patients, with respiratory tract, skin, and urinary tract infections being the most common.
Hypogammaglobulinemia is the most common cause of immunodeficiency in CLL patients, accounting for about 85 percent of all cases.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 83
Incorrect
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A 66-year-old male was admitted from the Emergency Department due to severe pain in the left forearm and hand, refractory to pain medication along with pallor and hypothermia of the affected limb. Ultrasound doppler showed an arterial embolism. Circulation was restored after vascular surgery, but there was extensive, irreversible muscle damage.
How will the muscle heal from an injury of this type?Your Answer: Volkmann’s ischaemic contracture
Correct Answer: Diffuse formation of fibrous tissue
Explanation:Once muscle tissue is damaged, there will be healing via diffuse formation of fibrous tissue, especially due to the widespread ischemia.
Callus formation takes place in the healing of bone, not muscle.
Organised scar formation occurs when a lacerated wound is approximated by sutures so that primary intention wound healing can occur.
Liquefaction degeneration occurs following ischemia in the brain.
Volkmann’s ischemic contracture may occur, but it is not the primary type of healing that will take place but rather the effect of the fibrous scar formation.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 84
Correct
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Regarding the hard palate, which of the following statements is CORRECT:
Your Answer: Lymphatic vessels from the palate usually drain into deep cervical lymph nodes.
Explanation:Lymphatic vessels from the pharynx and palate drain into the deep cervical lymph nodes.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 85
Incorrect
-
A 20-year-old male has an anaphylactic reaction following a wasp sting.
What type of hypersensitivity reaction is this?
Your Answer: Type V
Correct Answer: Type I
Explanation:Anaphylaxis is an example of a type I hypersensitivity reaction.
It is IgE mediated.
It requires a prior exposure to the antigen. The initial exposure sensitizes the body to the antigen and a second exposure to that antigen leads to an anaphylactic reaction.
Massive calcium influx into the cells leads to mast cell degranulation.
The Immunoglobulin antigen complex binds to Fc receptors on the surface of mast cells. The result is mast cell degranulation and release of histamine, proteoglycans and serum proteases from cytoplasmic granules.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 86
Incorrect
-
Haemophilia B results from a deficiency in:
Your Answer: Factor V
Correct Answer: Factor IX
Explanation:Haemophilia B is a bleeding disorder caused by a deficiency of clotting factor IX. It is the second commonest form of haemophilia, and is rarer than haemophilia A. Haemophilia B tends to be similar to haemophilia A but less severe. The two disorders can only be distinguished by specific coagulation factor assays.
The incidence is one-fifth of that of haemophilia A. Laboratory findings demonstrate prolonged APTT, normal PT and low factor IX.
Haemophilia B inherited in an X-linked recessive fashion, affecting males born to carrier mothers.
There is also a variation called Leyden, in which factor IX levels are below 1% until puberty, when they rise, potentially reaching as high as 40-60% of normal. This is thought to be due to the effects of testosterone at puberty. -
This question is part of the following fields:
- Haematology
- Pathology
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Question 87
Correct
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Regarding bicarbonate handling by the proximal tubule, which of the following statements is CORRECT:
Your Answer: For each H + secreted into the lumen, one Na + and one HCO 3 - is reabsorbed into the plasma.
Explanation:About 80% of bicarbonate is reabsorbed in the proximal tubule. HCO3-is not transported directly, tubular HCO3-associates with H+secreted by epithelial Na+/H+antiporters to form carbonic acid (H2CO3) which readily dissociates to form carbon dioxide and water in the presence of carbonic anhydrase. CO2and water diffuse into the tubular cells, where they recombine to form carbonic acid which dissociates to H+and HCO3-. This HCO3-is transported into the interstitium largely by Na+/HCO3-symporters on the basolateral membrane (and H+is secreted back into the lumen). For each H+secreted into the lumen, one Na+and one HCO3-are reabsorbed into the plasma. H+is recycled so there is little net secretion of H+at this stage.
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This question is part of the following fields:
- Physiology
- Renal
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Question 88
Incorrect
-
Flumazenil is a reversal agent for which of the following groups of drugs:
Your Answer: Barbiturates
Correct Answer: Benzodiazepines
Explanation:Flumazenil is a benzodiazepine antagonist used for the reversal of the sedative effects of benzodiazepines after anaesthesia, sedation and similar procedures.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 89
Incorrect
-
A 52-year-old woman visits her local pharmacy to get medication to help with mild dyspepsia symptoms. The pharmacist on duty suggests she uses an over-the-counter antacid. She purchases an antacid that contains magnesium carbonate, which relieves her symptoms, but she unfortunately also develops a side effect.
Out of the following, which side effect is she MOST likely to develop after using the antacid?Your Answer: Renal impairment
Correct Answer: Diarrhoea
Explanation:Magnesium carbonate is an over the counter antacid commonly used to relieve symptoms in ulcer dyspepsia and non-erosive gastro-oesophageal reflux.
Antacids containing magnesium also tend to work as a laxative, while the antacids with aluminium may cause constipation. There is no significant increased risk of anaphylaxis, hepatotoxicity or renal impairment.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 90
Correct
-
Which of the following statements accurately describes the extensor indicis muscle?
Your Answer: It lacks the juncturae tendinum
Explanation:Extensor indicis is a narrow, elongated muscle found in the posterior compartment of the forearm. It belongs to the deep extensors of the forearm, together with supinator, abductor pollicis longus, extensor pollicis longus, and extensor pollicis brevis muscles. It lacks the juncturae tendinum, which connects the extensor digitorum on the dorsal aspect of the hand.
Extensor indicis can be palpated by applying deep pressure over the lower part of the ulna while the index finger is extended. The main function of extensor indicis involves the extension of the index finger at the metacarpophalangeal and interphalangeal joints. As the index finger is one of the few fingers that have their own separate extensor muscle, it is able to extend independently from other fingers. Additionally, extensor indicis muscle produces a weak extension of the wrist.
Extensor indicis receives its nervous supply from posterior interosseous nerve, a branch of the radial nerve derived from spinal roots C7 and C8. The skin overlying the muscle is supplied by the same nerve, with fibres that stem from the spinal roots C6 and C7.
The superficial surface of the extensor indicis receives arterial blood supply from posterior interosseous branch of the ulnar artery, whereas its deep surface receives blood from perforating branches of the anterior interosseous artery.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 91
Incorrect
-
You investigated a patient with a chest infection and want to start antibiotics right away. The patient says they she can't take cephalosporins when you ask about allergies.
Choose the 'second-generation' cephalosporin from the following choices?Your Answer: Ceftazidime
Correct Answer: Cefuroxime
Explanation:Cephalosporins of the first generation include cephalexin, cefradine, and cefadroxil. Urinary tract infections, respiratory tract infections, otitis media, and skin and soft-tissue infections are all treated with them.
Second-generation cephalosporins include cefuroxime, cefaclor, and cefoxitin. These cephalosporins are less vulnerable to beta-lactamase inactivation than the ‘first-generation’ cephalosporins. As a result, they’re effective against germs that are resistant to other antibiotics, and they’re especially effective against Haemophilus influenzae.
Cephalosporins of the third generation include cefotaxime, ceftazidime, and ceftriaxone. They are more effective against Gram-negative bacteria than second generation’ cephalosporins. They are, however, less effective against Gram-positive bacteria such Staphylococcus aureus than second-generation cephalosporins.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 92
Incorrect
-
You examine a 48-year-old patient who has had proximal weakness, hypertension, and easy bruising in the past. She exhibits considerable face fullness and truncal obesity on examination. You diagnose her�with Cushing's syndrome.
When would her random cortisol level likely be abnormal?Your Answer: 1200 hrs
Correct Answer: 2400 hrs
Explanation:Cortisol levels fluctuate throughout the day, with the greatest levels occurring around 0900 hours and the lowest occurring at 2400 hrs during sleep.
The diurnal swing of cortisol levels is lost in Cushing’s syndrome, and levels are greater throughout the 24-hour period. In the morning, levels may be normal, but they may be high at night-time, when they are generally repressed.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 93
Incorrect
-
Gastric emptying is increased by all of the following EXCEPT for:
Your Answer: Distension of the pyloric antrum
Correct Answer: Secretin
Explanation:Gastric emptying is increased by:
Distension of the pyloric antrum
A fall in the pH of chyme in the stomach
Parasympathetic stimulation (via vagus)
Gastrin
The hormones secretin, cholecystokinin and gastric inhibitory polypeptide (GIP) inhibit gastric emptying. -
This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 94
Incorrect
-
Regarding the varicella zoster virus, which of the following statements is CORRECT:
Your Answer: Childhood chickenpox should be treated with oral antiviral medication.
Correct Answer: Contracting chickenpox infection while pregnant is associated with a higher risk of developing varicella pneumonitis.
Explanation:Chickenpox infection in neonates, adults/adolescents and pregnant women is associated with more severe disease. Varicella zoster pneumonitis typically occurs in pregnant women or immunocompromised individuals and is associated with a high mortality. A live attenuated-virus vaccine is available and recommended for non-immune healthcare workers but is not part of the routine childhood immunisation schedule. Antiviral treatment is not typically recommended in childhood chickenpox but is indicated for shingles.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 95
Incorrect
-
A 34-year-old man presented to the emergency room after being involved in a road traffic accident. Upon observation and examination, it was noted that he was hypotensive and has muffled heart sounds. It was suspected that he has pericardial effusion, so an emergency pericardiocentesis was to be performed.
In performing pericardiocentesis for suspected pericardial effusion, which of the following anatomical sites are at risk of being punctured?Your Answer: 1 cm below the right xiphocostal angle
Correct Answer: 1 cm below the left xiphocostal angle
Explanation:Pericardiocentesis is a procedure done to remove fluid build-up in the sac around the heart known as the pericardium. The pericardium can be tapped from almost any reasonable location on the chest wall. However, for the usual blind pericardiocentesis, the subxiphoid approach is preferred. Ideally, 2-D echocardiography is used to guide needle insertion and the subsequent path of the needle/catheter.
In the subxiphoid approach, the needle is inserted 1 cm inferior to the left xiphocostal angle with an angle of 30 degrees from the patient’s chest with a direction towards the left mid-clavicle.
The fingers may sense a distinct give when the needle penetrates the parietal pericardium. Successful removal of fluid confirms the needle’s position.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 96
Incorrect
-
Regarding Clostridium species, which of the following statements is INCORRECT:
Your Answer: They are rod-shaped.
Correct Answer: They are facultative anaerobes.
Explanation:Clostridium spp. are obligatory anaerobic spore-forming Gram-positive bacilli. Toxin production is the main pathogenicity mechanism.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 97
Incorrect
-
A 27-year-old female is brought to the Emergency Department by ambulance with extensive bleeding from her upper arm following a fall from a bicycle onto a fence. On inspection her biceps brachii muscle has been lacerated.
How will the muscle heal from this injury? Select ONE answer only.Your Answer: There will be formation of a large number of contractile myocytes
Correct Answer: Satellite cells will produce a small number of regenerated myocytes
Explanation:Muscle heals with fibrous tissue to form a scar. Once cut, it will never regain its previous bulk or power. Within the scar a small number of myocytes (muscle cells) may be seen, which are formed from satellite cells but they contribute little to the function of the muscle overall.
In more widespread ischaemic injury, such as critical ischaemic limb due to arterial compromise, or in compartment syndrome, damaged myocytes are replaced diffusely with fibrous tissue. This fibrous tissue contracts and reduces movement, and in extreme cases can pull the limb into abnormal positions such as in Volkmann’s ischaemic contracture of the forearm. -
This question is part of the following fields:
- General Pathology
- Pathology
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Question 98
Incorrect
-
Regarding Legionella species which of the following statements is CORRECT:
Your Answer: Legionella jeonii is the main human pathogen.
Correct Answer: They are Gram-negative organisms.
Explanation:Legionella pneumophilais a Gram negative bacterium that is found in natural water supplies and in the soil, transmitted predominantly via inhalation of aerosols generated from contaminated water (direct person-to-person spread of infected patients does not occur). It is the cause of Legionnaires’ disease. Outbreaks of Legionnaires’ disease have been linked to poorly maintained air conditioning systems, whirlpool spas and hot tubs.
The clinical features of the pneumonic form of Legionnaires’ disease include:
Mild flu-like prodrome for 1-3 days
Cough (usually non-productive and occurs in approximately 90%)
Pleuritic chest pain
Haemoptysis
Headache
Nausea, vomiting and diarrhoea
Anorexia
Legionella pneumophilainfections can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used.
The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur with Legionnaires’ disease and will result in hyponatraemia as is seen in this case.
Legionella pneumophilainfections are resistant to amoxicillin but can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used. The majority of cases of Legionnaires’ disease are caused by Legionella pneumophila, however many other species of Legionella have been identified.
Legionella longbeachae is another less commonly encountered species that has also been implicated in outbreaks. It is predominantly found in soil and potting compost, and has caused outbreaks of Pontiac fever, the non-respiratory and less severe variant of Legionnaires’ disease. -
This question is part of the following fields:
- Microbiology
- Pathogens
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Question 99
Incorrect
-
A 22-year-old man comes to the emergency department with a human bite injury to his hand received from a punch during a fight 3 hours earlier outside a bar. On closer inspection, you discover bite marks on his first and second knuckles. Which of the following is the best treatment option for this patient:
Your Answer: Oral metronidazole for 7 days
Correct Answer: Oral co-amoxiclav for 7 days
Explanation:Even if there is no evidence of infection, prophylactic antibiotics should be administered for all human bite wounds that are less than 72 hours old. The first-line therapy is 7 days of co-amoxiclav. In penicillin-allergic people, metronidazole + doxycycline is an option. Streptococcus spp., Staphylococcus aureus, Haemophilus spp., Eikenella corrodens, Bacteroides spp., and other anaerobes are the most prevalent organisms found in human bites.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 100
Incorrect
-
A 54-year-old man who is acutely unwell has his blood sent for test and the results come back with a CRP of 115.
Which of these statements about C-reactive protein is FALSE?
Your Answer: It rises in response to an increase in the plasma concentration of IL-6
Correct Answer: It is produced in the bone marrow
Explanation:C-reactive protein(CRP) is synthesized in the liver in response to increased interleukin-6 (IL-6) secretion by macrophages and T-cells.
Some conditions that cause CRP levels to a rise include: bacterial infection, fungal infection, severe trauma, autoimmune disease, Organ tissue necrosis, malignancy and surgery.It is useful in the clinical setting as a marker of inflammatory activity and can be used to monitor infections.
CRP levels start to rise 4-6 hours after an inflammatory trigger and reaches peak levels at 36-50 hours.
In the absence of a disease process, the normal plasma concentration is less than 5 mg/l.
CRP is useful for monitoring inflammatory conditions (e.g. rheumatoid arthritis and malignancy), can be used as a prognostic marker in acute pancreatitis, and serial measurement can be used to recognize the onset of nosocomial infections in the intensive care settling.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 101
Incorrect
-
The 'bucket handle' movement of the thoracic wall describes which of the following movements:
Your Answer: The sternum moving upwards and forwards
Correct Answer: The middles of the shafts of the ribs moving upwards and laterally
Explanation:Because the middles of the shafts of the ribs are lower than either the anterior or posterior end, elevation of the ribs also moves the middles of the shafts laterally. This ‘bucket handle’ upwards and lateral movement increases the lateral dimensions of the thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 102
Incorrect
-
A patient who is taking ramipril for high blood pressure complains of a dry persistent cough. What is the mechanism of cough in ACE inhibitor therapy:
Your Answer: Direct stimulation of irritant receptors
Correct Answer: Decreased bradykinin breakdown
Explanation:Blocking ACE also diminishes the breakdown of the potent vasodilator bradykinin which is the cause of the persistent dry cough. Angiotensin-II receptor blockers do not have this effect, therefore they are useful alternative for patients who have to discontinue an ACE inhibitor because of persistent cough.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 103
Correct
-
Which of the following is most true of the sinoatrial node:
Your Answer: Frequency of depolarisation is increased by sympathetic stimulation.
Explanation:Cardiac myocyte contraction is not dependent on an external nerve supply but instead the heart generates its own rhythm, demonstrating inherent rhythmicity. The heartbeat is initiated by spontaneous depolarisation of the sinoatrial node (SAN), a region of specialised myocytes in the right atrium close to the coronary sinus, at a rate of 100-110 beats/min. This intrinsic rhythm is primarily influenced by autonomic nerves, with vagal influences being dominant over sympathetic influences at rest. This vagal tone reduces the resting heart rate down to 60-80 beats/min. To increase heart rate, the autonomic nervous system increases sympathetic outflow to the SAN, with concurrent inhibition of vagal tone. These changes mean the pacemaker potential more rapidly reaches the threshold for action potential generation.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 104
Incorrect
-
Identify the type of graph described below:
A graph wherein the frequency distribution is represented by adjoining vertical bars and cases are stacked in adjoining columns. It can be used for continuous quantitative data, such as to analyse outbreak data to show an epidemic curve.Your Answer: Stem and leaf plot
Correct Answer: Histogram
Explanation:A histogram is used to demonstrate the distribution of continuous quantitative data. It is a very familiar graphical display device for representing the distribution of a single batch of data. The range of the data is divided into class intervals or bins, and the number of values falling into each interval is counted. The histogram then consists of a series of rectangles whose widths are defined by the class limits implied by the binwidths, and whose heights depend on the number of values in each bin. Histograms quickly reveal such attributes of the data distribution as location, spread, and symmetry. If the data are multimodal (i.e., more than one “hump” in the distribution of the data), this is quickly evident as well.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 105
Correct
-
Angiotensin II acts to cause all but which one of the following effects:
Your Answer: Inhibit release of ADH from the posterior pituitary gland
Explanation:Angiotensin II acts to:
Stimulate release of aldosterone from the zona glomerulosa of the adrenal cortex (which in turn acts to increase sodium reabsorption)
Cause systemic vasoconstriction
Cause vasoconstriction of the renal arterioles (predominant efferent effect thus intraglomerular pressure is stable or increased, thereby tending to maintain or even raise the GFR)
Directly increase Na+reabsorption from the proximal tubule (by activating Na+/H+antiporters)
Stimulate synthesis and release of ADH from the hypothalamus and posterior pituitary respectively
Stimulate the sensation of thirst
Potentiate sympathetic activity (positive feedback)
Inhibit renin production by granular cells (negative feedback) -
This question is part of the following fields:
- Physiology
- Renal
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Question 106
Incorrect
-
Which nerve supplies the muscle flexor hallucis longus?
Your Answer: Superficial peroneal nerve
Correct Answer: Tibial nerve
Explanation:Flexor hallucis longus is innervated by the tibial nerve, composed of spinal roots L4, L5, S1, S2, and S3.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 107
Incorrect
-
A patient is currently taking is glyceryl trinitrate among other chronic medications. Which of the following side effects is he LEAST likely to develop?
Your Answer: Cerebral ischaemia
Correct Answer: Syncope
Explanation:Nitrates are used in the treatment of angina pectoris and the prevention of myocardial ischaemia. Commonly used examples of nitrates are glyceryl trinitrate and isosorbide dinitrate. Unwanted effects, however, are common and can limit therapy, particularly when angina is severe or when patients are unusually sensitive to the effects of nitrates.
The following are common or very common side effects of nitrates:
- Arrhythmias
- Asthenia
- Cerebral ischaemia
- Dizziness
- Drowsiness
- Flushing
- Headache
- Hypotension
- Nausea and vomiting
- Diarrhoea, syncope and cyanosis can occur, but these are rare side effects.
Dry eyes, bradycardia and metabolic acidosis have not been reported.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 108
Incorrect
-
Which of the following statements is false regarding the biceps brachii muscle?
Your Answer: It weakly assists with flexion of the arm at the shoulder
Correct Answer: It pronates the radioulnar joint in the forearm
Explanation:The biceps brachii muscle is one of the chief muscles of the arm. The origin at the scapula and the insertion into the radius of the biceps brachii means it can act on both the shoulder joint and the elbow joint, which is why this muscle participates in a few movements of the arm. It derives its name from its two heads which merge in one unique distal body, defining the unusual structure of the muscle.
The biceps brachii muscle is supplied by the musculocutaneous nerve (C5-C6), a branch of the brachial plexus.
Arterial supply to the biceps brachii muscle varies considerably, coming from up to eight vessels originating from the brachial artery in the middle third of the arm.
In the shoulder joint both muscle heads partially enforce opposite movements. The long head pulls the arm away from the trunk (abduction) and turns it inwards (inward rotation) whereas the short head pulls the arm back towards the trunk (adduction). When both heads contract simultaneously it leads to an arm bend (flexion). In the elbow joint the muscle bends the forearm (flexion) and rotates it outwards (supination). The supination is most powerful in a flexed elbow. In addition to the movement functions, the biceps has the important task to support the humeral head within the shoulder joint. Its antagonist is the triceps brachii in the posterior compartment of the arm.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 109
Incorrect
-
A new chemotherapy drug is being tested. The intervention reduces the risk of death from 10 in 1000 to 5 in 1000. What is the number needed to treat to prevent one death:
Your Answer: 5
Correct Answer: 200
Explanation:Absolute risk reduction (ARR) of treatment
= risk of death in control group – risk of death in treatment group
ARR = (10/1000) – (5/1000)
= 5/1000 = 0.005
Number needed to treat (NNT)
= 1/ARR
= 1/0.005
= 200
Therefore 200 people would need to be treated to prevent one extra death. -
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 110
Incorrect
-
Reed-Sternberg cells are characteristic of which of the following malignancies:
Your Answer: Multiple Myeloma
Correct Answer: Hodgkin lymphoma
Explanation:Lymphomas are a group of diseases caused by malignant lymphocytes that accumulate in lymph nodes and other lymphoid tissue and cause the characteristic clinical feature of lymphadenopathy. The major subdivision of lymphomas is into Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) and this is based on the histological presence of Reed-Sternberg cells present in HL. Hodgkin lymphoma can present at any age but is rare in children and has a peak incidence in young adults. There is an almost 2 : 1 male predominance. Most patients present with painless, asymmetrical, firm and discrete enlargement of superficial lymph nodes. Cervical nodes are involved in 60-70% of cases, axillary nodes in 10-15% and inguinal nodes in 6-12%. Modest splenomegaly occurs during the course of the disease in 50% of patients; the liver may also be enlarged. Bone marrow failure involvement is unusual in early disease. The prognosis depends on age, stage and histology, but overall approximately 85% of patients are cured. Alcohol‐induced pain and pruritus are two well‐known but rare symptoms in HL.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 111
Incorrect
-
Following the administration of a medication for a heart condition, a 69-year-old man develops hypothyroidism.
Which of the following drugs is most likely to be the cause?Your Answer: Flecainide
Correct Answer: Amiodarone
Explanation:Amiodarone has a chemical structure that is similar to that of thyroxine and can bind to the nuclear thyroid receptor. It can cause both hypothyroidism and hyperthyroidism, though hypothyroidism is far more common, with 5-10% of patients suffering from it.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 112
Incorrect
-
A 22-year-old presents with acute severe asthma. He takes a drug prescribed by her GP but cannot recall the name and is receiving regular salbutamol nebulisers. His current potassium level is 2.8 mmol/l.
Which drug is least likely to have caused his hypokalaemia?
Your Answer: Uniphyllin continus
Correct Answer: Spironolactone
Explanation:Serious hypokalaemia can occur in severe asthma and the effect can be potentiated by concomitant treatment with theophyllines like aminophylline, corticosteroids, thiazide and loop diuretics, and hypoxia. Plasma-potassium concentration should be monitored in severe asthma.
Spironolactone, a potassium-sparing diuretic, is not likely to have contributed to patients hypokalaemia.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 113
Incorrect
-
Approximately what proportion of lymphocytes are B-cells:
Your Answer: 0.65
Correct Answer: 0.2
Explanation:B-cells (20% of lymphocytes) mature in the bone marrow and circulate in the peripheral blood until they undergo recognition of antigen. B-cell immunoglobulin molecules synthesised in the cell are exported and bound to the surface membrane to become the B-cell receptor (BCR) which can recognise and bind to a specific antigen (either free or presented by APCs). The BCR is also important for antigen internalisation, processing and presentation to T helper cells. Most antibody responses require help from antigen-specific T helper cells (although some antigens such as polysaccharide can lead to T-cell independent B-cell antibody production). When the B-cell is activated, the receptor itself is secreted as free soluble immunoglobulin and the B-cell matures into a memory B-cell or a plasma cell (a B-cell in its high-rate immunoglobulin secreting state). Plasma cells are non-motile and are found predominantly in the bone marrow or spleen. Most plasma cells are short-lived (1 – 2 weeks) but some may survive much longer. A proportion of B-cells persist as memory cells, whose increased number and rapid response underlies the augmented secondary response of the adaptive immune system.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 114
Incorrect
-
Regarding the factor V Leiden gene mutation, which of the following best describes the clinical effect:
Your Answer: It results in deficiency of factor V.
Correct Answer: It results in increased levels of activated factor V.
Explanation:Factor V Leiden gene mutation is the most common inherited cause of an increased risk of venous thrombosis. Activated protein C normally breaks down activated factor V and so should slow the clotting reaction and prolong the APTT, but a mutation in the factor V gene makes factor V less susceptible to cleavage by activated protein C, resulting in increased levels of activated factor V.Heterozygotes for factor V Leiden are at an approximately five- to eight- fold increased risk of venous thrombosis compared to the general population (but only 10% of carriers will develop thrombosis in their lifetime). Homozygotes have a 30 – 140-fold increased risk. The incidence of factor V Leiden in patients with venous thrombosis is approximately 20 – 40%. It does not increase the risk of arterial thrombosis.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 115
Incorrect
-
A 15-year-old male is admitted to a rehabilitation centre with a history of multiple strokes, myopathy and learning disabilities since childhood. He is under the care of a multidisciplinary team, and his genetic testing reports show the presence of a mitochondrial disorder.
Which one of the following diseases does this patient most likely have?Your Answer: Spinal muscular atrophy
Correct Answer: MELAS
Explanation:Mitochondrial diseases are a group of disorders caused by dysfunctional mitochondria. Most cases are maternally inherited, as we inherit our mitochondrial DNA from our mothers only, although mutations in nuclear DNA cause some cases.
Examples of Mitochondrial Diseases include:
1. Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS)
2. Mitochondrial epilepsy with ragged red fibres (MERRF)
3. Leber’s hereditary optic neuropathy (LHON)
4. Diabetes mellitus and deafness (DAD)
5. Neuropathy, ataxia, retinitis pigmentosa, and ptosis (NARP)
6. Leigh syndrome (subacute sclerosing encephalopathy).Red-green colour blindness and G6PD deficiency have an X-linked recessive pattern of inheritance.
Tay-Sachs Disease and spinal muscular atrophy have an autosomal recessive pattern of inheritance.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 116
Incorrect
-
A 49-year-old man known sickle cell disease patient received a blood transfusion and developed a mild fever and dark urine 6 days after transfusion. His investigations show raised bilirubin, raised LDH, and a positive Direct Antiglobulin Test (DAT).
Which transfusion reaction is most likely occurred?Your Answer: Acute haemolytic reaction
Correct Answer: Delayed haemolytic reaction
Explanation:Delayed haemolytic transfusion reactions (DHTRs) commonly occurs 4-8 days after blood transfusion, but can occur up to a month after. Signs and symptoms include jaundice, fever, an inadequate rise in PCV, reticulocytosis, a positive antibody screen and a positive Direct Antiglobulin Test (Coombs test). DHTRs usually have a benign course and require no treatment but sometimes, life-threatening haemolysis with severe anaemia and renal failure can occur so haemoglobin levels and renal function should be monitored.
Acute haemolytic reaction aka immediate haemolytic transfusion reaction presents with fever, chills, pain at transfusion site, nausea, vomiting, dark urine and feeling of ‘impending doom’. Often, it occurs due to ABO incompatibility.
Febrile transfusion reaction presents with a 1 degree rise in temperature from baseline during transfusion. Patient may have chills and malaise. It is the most common transfusion reaction (1 in 8 transfusions) and is usually caused by cytokines released from leukocytes in transfused red cell or platelet components.
Transfusion-associated circulatory overload (TACO) presents as acute or worsening respiratory distress within 6 hours of transfusion of a large volume of blood. It is common in patients with diminished cardiac reserve or chronic anaemia. Elderly patients, infants and severely anaemic patients are particularly susceptible. Clinical features of TACO include: Acute respiratory distress, Tachycardia, Hypertension, Acute/worsening pulmonary oedema on chest X-ray. The BNP is usually raised to at least 1.5 times the pre-transfusion baseline.
Graft versus host disease(GVHD) is an immune mediated condition that arises from a complex interaction between donor and recipients adaptive immunity. It presents as dermatitis, hepatitis and enteritis developing within 100 days after stem cell or bone marrow transplant.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 117
Correct
-
A 47-year-old woman comes in with palpitations that have been bothering her for the past four days. Her haemodynamics are normal, but her heart rate is currently 150 beats per minute. An ECG is performed, which reveals that she is experiencing atrial flutter. The patient is examined by a cardiology registrar, who recommends starting her on verapamil to control her ventricular rate while she waits for cardioversion.
In these circumstances, which of the following is a contraindication to the use of verapamil?Your Answer: Acute porphyria
Explanation:In most cases of atrial flutter, ventricular rate control is used as a stopgap measure until sinus rhythm is restored. A beta-blocker (e.g. bisoprolol), diltiazem, or verapamil can be used to reduce the rate of contractions in the heart.
Electrical cardioversion, pharmacological cardioversion, and catheter ablation can all be used to return the heart to a normal rhythm. Cardioversion should not be attempted until the patient has been fully anticoagulated for at least three weeks if the duration of atrial flutter is unknown or it has lasted longer than 48 hours. Emergency electrical cardioversion is the treatment of choice when there is a sudden onset of symptoms and haemodynamic compromise. For recurrent atrial flutter, catheter ablation is preferred.Verapamil is a calcium-channel blocker that is non-dihydropyridine phenylalkylamine and can be used to treat supraventricular arrhythmias. It’s a calcium channel blocker with a high negative inotropic effect that lowers cardiac output, slows the heart rate, and may impair atrioventricular conduction. At high doses, it can cause heart failure, exacerbate conduction disorders, and cause hypotension.
Adults should take 240-480 mg of verapamil in 2-3 divided doses. 5-10 mg IV over 30 seconds is the corresponding intravenous (IV) dose. After an IV injection, the peak effect lasts 3-5 minutes, and the action lasts 10-20 minutes.
Verapamil should not be taken with beta-blockers like atenolol or quinidine because the combination of their negatively inotropic and negatively chronotropic effects can result in severe hypotension, bradycardia, impaired atrioventricular conduction, heart failure (due to impaired cardiac contractility), and sinus arrest.
The use of verapamil is contraindicated in the following situations:
Acute porphyrias are a type of porphyria that occurs suddenly.
Accessory conducting pathways are linked to atrial flutter or fibrillation (e.g. Wolff-Parkinson-White-syndrome)
Bradycardia
Shock caused by the heart
Insufficiency of the heart (with reduced ejection fraction)
Left ventricular function has been significantly harmed in the past (even if controlled by therapy)
Hypotension (blood pressure less than 90 mmHg)
AV block in the second and third degrees
Sinusitis is a condition in which the sinuses become
Sino-atrial occlusion -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 118
Incorrect
-
Regarding acute lymphoblastic leukaemia (ALL), which of the following statements is CORRECT:
Your Answer: Bence-Jones protein is seen in urine.
Correct Answer: 75% of cases occur before the age of 6 years.
Explanation:Acute lymphoblastic leukaemia (ALL) is caused by an accumulation of lymphoblasts in the bone marrow and is the most common malignancy of childhood. The incidence of ALL is highest at 3 – 7 years, with 75% of cases occurring before the age of 6. 85% of cases are of B-cell lineage. Haematological investigations reveal a normochromic normocytic anaemia with thrombocytopenia in most cases. There is great variation in the chance of individual patients achieving a long-term cure based on a number of biological variables. Approximately 25% of children relapse after first-line therapy and need further treatment but overall 90% of children can expect to be cured. The cure rate in adults drops significantly to less than 5% over the age of 70 years.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 119
Incorrect
-
In adult advanced life support, which of the following best describes the correct administration of adrenaline for a non-shockable rhythm:
Your Answer: Give 0.5 mg of adrenaline as soon as intravenous access is achieved and every 3 - 5 minutes thereafter
Correct Answer: Give 1 mg of adrenaline as soon as intravenous access is achieved and every 3 - 5 minutes thereafter
Explanation:IV adrenaline 1 mg (10 mL of 1:10,000 solution) should be given after 3 shocks and every 3 – 5 minutes/after alternate shocks thereafter.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 120
Incorrect
-
When inserting a Seldinger chest drain for management of pneumothorax, the 'safe triangle' should be identified. Which of the following forms the inferior border of the 'safe triangle'?
Your Answer: 4 th intercostal space
Correct Answer: 5 th intercostal space
Explanation:Care and management of the thoracostomy tubes (chest tubes) are subject to the direction and practice pattern of the responsible physician. Therefore, it is difficult to make a “one size fits all” set of instructions about the specific management recommendations for all chest tubes. It is recommended to discuss specific expectations for management with the patient’s attending physician. Facility specific Clinical Practice Guidelines (CPGs) may provide further guidance for one’s practice.
Placement of the appropriately sized chest tube is performed on the affected side. The typical landmark for placement is the 4th or 5th intercostal space (nipple line for males, inframammary fold for females) at the anterior axillary line. The space above the 5th intercostal space and below the base of the axilla that is bordered posteriorly by the trapezius and anteriorly by the pectoralis muscle has recently been described as the safe triangle. Tubes are positioned anteriorly for pneumothoraces and posteriorly for fluid processes.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 121
Incorrect
-
Which of the following is NOT a benefit of low molecular weight heparin (LMWH) over unfractionated heparin therapy:
Your Answer: It has a greater ability to inhibit factor Xa directly rather than inhibit antithrombin III.
Correct Answer: Its effects can be rapidly and completely reversed with protamine sulfate.
Explanation:Advantages of LMWHGreater ability to inhibit factor Xa directly, interacting less with platelets and so may have a lesser tendency to cause bleedingGreater bioavailability and longer half-life in plasma making once daily subcutaneous administration possibleMore predictable dose response avoiding the need for routine anticoagulant monitoringLower associated risk of heparin-induced thrombocytopenia or of osteoporosis
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 122
Incorrect
-
Which of the following bacteria is a rod-shaped, oxidase-positive, opportunistic gram-negative bacteria that can cause a catheter-related urinary tract infection (UTI)?
Your Answer: Candida albicans
Correct Answer: Pseudomonas aeruginosa
Explanation:Listeria monocytogenes is a gram-positive bacteria that does not produce spores.
Staphylococcus aureus is a gram-positive bacteria, while Candida albicans is a gram-positive yeast with a single bud.
Among the choices, gram-negative bacteria include only Klebsiella pneumoniae and Pseudomonas aeruginosa.
Pseudomonas aeruginosa is an oxidase-positive bacterium, while Klebsiella pneumoniae is an oxidase-negative bacterium.
P. aeruginosa can cause urinary tract infections (UTIs) and is spread through poor hygiene or contaminated medical equipment or devices, such as catheters that haven’t been fully sterilized.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 123
Correct
-
You review the arterial blood gas (ABG) of a patient with lactic acidosis.
Which SINGLE statement regarding lactic acidosis is true?Your Answer: Type A lactic acidosis is typically due to tissue hypoxia
Explanation:Lactic acidosis is defined as a pH <7.35 and a lactate >5 mmol/L. It is a common finding in critically ill patients and is often associated with other serious underlying pathologies. The anion gap is raised in lactic acidosis.
There are major adverse consequences of severe acidaemia, which affect all body systems, and there is an associated increase in mortality of critically ill patients with a raised lactate. The mortality associated with lactic acidosis despite full supportive treatment remains at 60-90%.
Acquired lactic acidosis is classified into two subtypes:
Type A is due to tissue hypoxia
Type B is due to non-hypoxic processes affecting the production and elimination of lactate
Lactic acidosis can be extreme after a seizure but usually resolves spontaneously within a few hours.
Left ventricular failure typically results in tissue hypoperfusion and a type A lactic acidosis.
Some causes of type A and type B lactic acidosis are shown below:
Type A lactic acidosis
Type B lactic acidosis
Shock (including septic shock)
Left ventricular failure
Severe anaemia
Asphyxia
Cardiac arrest
CO poisoning
Respiratory failure
Severe asthma and COPD
Regional hypoperfusion
Renal failure
Liver failure
Sepsis (non-hypoxic sepsis)
Thiamine deficiency
Alcoholic ketoacidosis
Diabetic ketoacidosis
Cyanide poisoning
Methanol poisoning
Biguanide poisoning -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 124
Correct
-
While studying fluid homeostasis in the body, you encounter the term exudate. Exudate is a fluid that leaks out of the intravascular space due to changes in the permeability of the microcirculation secondary to inflammation.
Which ONE of the following conditions would not be listed among the causes of an exudate?Your Answer: Myxoedema
Explanation:An exudate is an inflammatory fluid that leaks out of the intravascular space due to increased vascular permeability and intravascular pressure. It is mostly caused by local processes and can occur in the following conditions:
1) Infection (e.g. pneumonia)
2) Malignancy
3) Pericarditis
4) Collagen vascular diseases, e.g., Rheumatoid ArthritisMyxoedema is a state of severe hypothyroidism in which deposition of mucopolysaccharides occurs in the dermis. This causes a transudative effusion, typically in the pretibial region.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 125
Incorrect
-
Which of the following is NOT a function of the commensal intestinal bacterial flora:
Your Answer: Convert primary bile acids to secondary bile acids
Correct Answer: Breakdown of haem into bilirubin
Explanation:Commensal intestinal bacterial flora have a role in:Keeping pathogenic bacteria at bay by competing for space and nutrientConverting conjugated bilirubin to urobilinogen (some of which is reabsorbed and excreted in urine) and stercobilinogen which is excreted in the faecesThe synthesis of vitamins K, B12, thiamine and riboflavinThe breakdown of primary bile acids to secondary bile acidsThe breakdown of cholesterol, some food additives and drugs
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 126
Incorrect
-
Loop diuretics primarily act on which Na+ transporter?
Your Answer: Na + /K + ATPase pump
Correct Answer: Na + /K + /2Cl - symporter
Explanation:The most potent diuretics are loop diuretics e.g. furosemide. They work by inhibiting the Na+/K+/2Cl-symporter in the thick ascending limb of the loop of Henle, which inhibits sodium, potassium, and chloride reabsorption. As a result, there is diuresis with loss of these electrolytes. There is a reduction in transcellular voltage difference, paracellular calcium and magnesium reabsorption.
The medullary interstitium becomes more concentrated by salt reabsorption in the ascending limb. Loop diuretics block this process and reduce the ability of the kidney to concentrate urine. In the collecting duct, there is increased sodium delivery to the principal cells, which increases potassium secretion in return for sodium reabsorption. -
This question is part of the following fields:
- Physiology
- Renal
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Question 127
Incorrect
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Which of the following ions is more abundant in extracellular fluid than in intracellular fluid:
Your Answer: Mg 2+
Correct Answer: Cl -
Explanation:Protein and phosphate are the primary intracellular anions, while chloride (Cl-) and bicarbonate are the predominant extracellular anions (HCO3-).
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 128
Incorrect
-
Which of the following is NOT a typical clinical feature of diabetic ketoacidosis:
Your Answer: Hypotension
Correct Answer: Cheyne–Stokes respiration
Explanation:Clinical features of DKA:
Symptoms: Polyuria, polydipsia, thirst, lethargy, weight loss, nausea, vomiting, anorexia, abdominal pain, dehydration, headache, altered mental state
Signs: Dry mucous membranes, ketotic breath, tachycardia, hypotension, Kussmaul breathing, focal signs of precipitant e.g. infection -
This question is part of the following fields:
- Endocrine
- Physiology
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Question 129
Incorrect
-
Regarding dermatophytes, which of the following statement is CORRECT:
Your Answer: The lesions of ringworm typically have a pale outer ring and a dark centre.
Correct Answer: Diagnosis is made from microscopy and culture of skin scrapings, hair samples or nail clippings.
Explanation:Diagnosis is made from microscopy and culture of skin scrapings, hair samples or nail clippings depending on the site of infection. The lesions of ringworm typically have a dark outer ring with a pale centre. Tinea capitis is ringworm affecting the head and scalp. Spread is via direct skin contact. Treatment is usually topical, oral antifungals are reserved for refractory infection.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 130
Incorrect
-
Regarding linear relationships between two variables, what does a positive correlation coefficient indicate:
Your Answer: As one variable decreases, the other variable increases
Correct Answer: The two variables are directly proportional
Explanation:A positive correlation coefficient means that the two variables are directly proportional e.g. height and weight in healthy growing children.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 131
Incorrect
-
The 'pump handle' movement of the thoracic wall describes which of the following movements:
Your Answer: The internal intercostal muscles elevating the ribs
Correct Answer: The anterior ends of the ribs moving upwards and forwards
Explanation:Because the anterior ends of the ribs are inferior to the posterior ends, when the ribs are elevated, the anterior end moves upwards and forwards, moving the sternum upwards and forwards in turn. This ‘pump handle’ upwards and forwards movement changes the anteroposterior (AP) dimension of the thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 132
Incorrect
-
A 2-day-old male is referred to a tertiary care hospital by the community midwife after a home visit due to jaundice and dyspnoea. After history and examination, the relevant blood work is performed, and the baby is found to have conjugated hyperbilirubinemia. The paediatric team suspects a hepatic origin for jaundice based on the findings.
Which one of the following aetiologies is the most likely cause of jaundice in this case?Your Answer: Hereditary spherocytosis
Correct Answer: Alpha 1-antitrypsin deficiency
Explanation:The presence of dyspnoea makes alpha-1 antitrypsin deficiency the more likely diagnosis as biliary atresia does not cause respiratory symptoms. Deficiency of the enzyme alpha-1 antitrypsin causes uninhibited elastase activity and a decrease in elastic tissue. This causes liver cirrhosis leading to an elevation of conjugated bilirubin and emphysema in the lungs.
Rhesus disease, hereditary spherocytosis and breast milk jaundice cause an elevation of unconjugated bilirubin thus ruling it out in this case. Breast milk jaundice occurs due to an inability of the newborn to metabolize the proteins in breast milk.
Rhesus disease occurs when an Rh negative mother gives birth to an Rh positive baby. The jaundice would have been accompanied by anaemia and oedema.
Hereditary spherocytosis occurs due to extravascular haemolysis as defective RBCs are removed by the spleen. The patient would present with jaundice, splenomegaly and possibly an aplastic crisis (if Parvovirus B19 infection).
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 133
Incorrect
-
A 43 year old lady who has a previous medical history of hyperthyroidism presents to the emergency room with sweating, palpitations and agitation. On examination, she is tachycardic, hypertensive and hyperpyrexic. She recently had a stomach bug and has not been able to take her medication regularly. The best medication to immediately treat her symptoms is which of the following?
Your Answer: Lithium
Correct Answer: Propranolol
Explanation:There is a high suspicion of a thyroid crisis in this patient and emergent treatment should be initiated even before the results of TFT’s have returned. Antiadrenergic drugs like IV propranolol should be administered immediately to minimise sympathomimetic symptoms. Antithyroid medications like propylthiouracil or carbimazole should be administered to block further synthesis of thyroid hormones. After thionamide therapy has been started to prevent stimulation of new hormone synthesis, there should then be delayed administration of oral iodine solution. Hydrocortisone administration is also recommended as it treats possible relative adrenal insufficiency while also decreases peripheral conversion of T4 to T3.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 134
Incorrect
-
A 6-year-old girl is brought to the nephrology clinic by her mother due to facial oedema. Her lab workup shows proteinuria of 7 g/24 hours and serum albumin levels of 15 g/L. A diagnosis of Nephrotic Syndrome is made, and corticosteroid therapy is initiated.
Which one of the following is the most likely cause of nephrotic syndrome in this patient?Your Answer: Hepatitis B infection
Correct Answer: Minimal change disease
Explanation:Minimal Change Disease is the most common cause of Nephrotic Syndrome in the paediatric population. It may be caused by NSAID use. Electron microscopy shows the fusion of foot processes while light microscopy will appear normal.
Focal segmental glomerulosclerosis causes Nephrotic Syndrome in adults. It is associated with Heroin use and HIV infection. There is a limited response to steroids, and the disease progresses to end-stage renal failure in 5-10 years.
Diabetic nephropathy occurs after a long period of diabetes due to the deposition of amyloid protein leading to a decrease in glomerular filtration.
There is no history of Hepatitis B in this patient and no symptoms of liver disease such as jaundice.
Membranous glomerulonephritis would present with features of Nephritic Syndrome. These would be oedema, haematuria; red blood cell casts in the urine and hypertension.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 135
Incorrect
-
Typically, granulomatous inflammation is associated with one of the following infections:
Your Answer: HIV
Correct Answer: Tuberculosis
Explanation:Granulomatous inflammation is typically seen when an infective agent with a digestion-resistance capsule (e.g. Mycobacterium tuberculosis) or a piece of inert foreign material (such as suture or glass) is introduced into the tissue. A transient acute inflammatory response occurs and when this is ineffective in eradicating the stimulus, chronic inflammation occurs.
Tuberculosis is the prototype of the granulomatous diseases, but sarcoidosis, cat-scratch disease, lymphogranuloma inguinale, leprosy, brucellosis, syphilis, some mycotic infections, berylliosis, reactions of irritant lipids, and some autoimmune diseases are also included
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 136
Incorrect
-
Fat necrosis is typically seen in which of the following:
Your Answer: Myocardial infarction
Correct Answer: Acute pancreatitis
Explanation:Fat necrosis typically occurs following either direct trauma or from enzymatic lipolysis in acute pancreatitis, where release of triglyceride elicits a rapid inflammatory response and fat is phagocytosed by neutrophils and macrophages with subsequent fibrosis.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 137
Incorrect
-
The juxtacapillary receptors, or J receptors, are sensory cells that play an important role in the control of respiration.
At which of the following anatomical sites are the J receptors located? Select ONE answer only.Your Answer: The carotid artery
Correct Answer: The alveolar walls
Explanation:Juxtacapillary receptors (J receptors) are sensory cells that are located within the alveolar walls in juxtaposition to the pulmonary capillaries of the lung.
The J receptors are innervated by the vagus nerve and are activated by physical engorgement of the pulmonary capillaries or increased pulmonary interstitial volume, for example, in the presence of pulmonary oedema, pulmonary embolus, pneumonia and barotraumas. They may also be stimulated by hyperinflation of the lung.
Stimulation of the J receptors causes a reflex increase in breathing rate and is also thought to be involved in the sensation of dyspnoea. The reflex response that is produced is apnoea, followed by rapid breathing, bradycardia, and hypotension. -
This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 138
Correct
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All of the following statements are correct regarding penicillin antibiotics except:
Your Answer: Penicillins are of no use in meningitis as they are unable to penetrate into the cerebrospinal fluid.
Explanation:Penicillin penetration into the cerebrospinal fluid is generally poor. However, when the meninges are inflamed, as in meningitis, penetration of penicillin is increased. Benzylpenicillin should be given before transfer to hospital if meningococcal disease (meningitis with non-blanching rash or meningococcal septicaemia) is suspected, once this does not delay transfer.
Benzylpenicillin is no longer the drug of first choice for pneumococcal meningitis.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 139
Incorrect
-
An 11-year-old boy was brought to the emergency room due to fever and pain in the ears. Upon physical examination, it was observed that the mastoid area is erythematous and there is a presence of a boggy, tender mass. A diagnosis of acute mastoiditis was made.
Which of the following parts of the temporal bone is most likely involved?Your Answer: Squamous part
Correct Answer: Petrous part
Explanation:Mastoiditis is the inflammation of a portion of the temporal bone referred to as the mastoid air cells. The mastoid air cells are epithelium lined bone septations that are continuous with the middle ear cavity.
The temporal bone is composed of four parts: the mastoid process, the petrous pyramid, the squamous, and tympanic portions. The mastoid process and the petrous pyramid are the portions of particular interest because of the prevalence of suppurations within these parts of the temporal bone.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 140
Incorrect
-
Which of the following is NOT a mineralocorticoid effect of corticosteroids:
Your Answer: Calcium loss
Correct Answer: Hyperglycaemia
Explanation:Mineralocorticoid side effects include:hypertensionsodium retentionwater retention and oedemapotassium losscalcium loss
Glucocorticoid side effects include:weight gainhyperglycaemia and diabetesosteoporosis and osteoporotic fracturesmuscle wasting (proximal myopathy)peptic ulceration and perforationpsychiatric reactions -
This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 141
Incorrect
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Regarding propofol, which of the following statements is INCORRECT:
Your Answer: Propofol reduces upper airway reflexes.
Correct Answer: A lower induction dose of propofol is required in children.
Explanation:Elderly patients have a reduced volume of distribution and slower clearance of the drug. They are therefore more sensitive to the effects of propofol and the drug wears off more slowly. They need less of the drug, which should be injected slowly, monitoring its effect on the patient. The opposite is true in children, who need larger doses of propofol. This is particularly so in children under three years of age. Propofol is not recommended for induction of anaesthesia in children under one month of age or for maintenance of anaesthesia in children under three years old.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 142
Correct
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An 11-year-old girl presents with a 5-day history of persistent fever despite regular paracetamol, throbbing left ear pain, ear discharge and deafness. Her parents have observed that she is not her usual self, not eating well, and has been lethargic. On examination there is a tender swelling in the post auricular region on the left hand side.
What is the most likely causative organism?
Your Answer: Streptococcus pneumonia
Explanation:Acute mastoiditis is a complication (rare) of acute otitis media (AOM) and the commonest causative organism is Streptococcus pneumoniae.
Generally, acute mastoiditis presents with:
Pyrexia
Recent history of AOM
Mastoid swelling and erythema
Otalgia
Otorrhoea and perforation of tympanic membrane
Post-auricular pain
Protrusion of the ears -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 143
Incorrect
-
A 55-year-old woman with mild dyspepsia seeks advice from her pharmacist on how to deal with her symptoms. In the first instance, the pharmacist advises her to take an over-the-counter antacid. She buys an antacid that contains aluminium hydroxide, which relieves her symptoms but has a negative side effect.
She's most likely to have developed which of the following side effects?Your Answer: Diarrhoea
Correct Answer: Constipation
Explanation:Aluminium hydroxide is a common antacid that is used to treat ulcer dyspepsia and non-erosive gastro-oesophageal reflux disease.
When antacids containing aluminium salts are given to patients with renal impairment, there is a risk of accumulation and aluminium toxicity. If renal function is normal, aluminium accumulation does not appear to be a risk.
Because it reduces gastrointestinal phosphate absorption, aluminium hydroxide can also be used to treat hyperphosphatemia in patients with renal failure.
Magnesium-based antacids are generally laxative, whereas aluminium-based antacids can be constipating. Renal impairment, angioedema, and anaphylaxis are not significantly increased.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 144
Incorrect
-
A 49-year-old woman with haemoglobin of 6 g/dL following persistent vaginal bleeding receives blood transfusion. She developed pain and burning at her cannula site and complains of a feeling of “impending doom”, nausea, and severe back pain shortly after transfusion was started. Her temperature is 38.9ºC.
What is the most appropriate treatment?Your Answer: Administer diuretics and slow the transfusion rate
Correct Answer: Stop the transfusion and administer IV fluids
Explanation:Acute haemolytic transfusion reactions present with: Feeling of ‘impending doom’ as the earliest symptom, fever and chills, pain and warmth at transfusion site, nausea and vomiting, back, joint, and chest pain. Transfusion should be stopped immediately and IV fluid (usually normal saline) administered.
Supportive measures and paracetamol can be given since patient has fever but it is not the immediate first step.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 145
Incorrect
-
Vitamin D is a group of secosteroids that play a role in calcium and phosphate control. Vitamin D's hormonally active metabolite is 1,25-dihydroxycholecalciferol.
Which enzyme hydroxylates 25-hydroxycholecalciferol to form 1,25-dihydroxycholecalciferol?Your Answer: UVA radiation
Correct Answer: 1-alpha-hydroxylase
Explanation:The hormone-active metabolite of vitamin D is 1,25-dihydroxycholecalciferol (commonly known as calcitriol). Its activities raise calcium and phosphate levels in the bloodstream.
In the presence of UVB light, 7-dehydrocholesterol is converted to cholecalciferol in the epidermal layer of the skin, resulting in 1,25-dihydroxycholecalciferol.
Cholecalciferol is then converted to 25-hydroxycholecalciferol in the endoplasmic reticulum of liver hepatocytes by 25-hydroxylase (calcifediol).
Finally, 1-alpha-hydroxylase converts 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol in the kidney. The key regulatory point in the formation of 1,25-dihydroxycholecalciferol is 1-alpha-hydroxylase, which is induced by parathyroid hormone or hypophosphatemia.
The following are the primary effects of 1,25-dihydroxycholecalciferol:
Calcium and phosphate absorption in the small intestine is increased.
Calcium reabsorption in the kidneys is increased.
Increases phosphate reabsorption in the kidneys.
Increases the action of osteoclastic bacteria (increasing calcium and phosphate resorption from bone)
Inhibits the action of 1-alpha-hydroxylase in the kidneys (negative feedback) -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 146
Incorrect
-
How does an action potential in the motor end plate rapidly spread to the central portions of the muscle cells?
Your Answer: Sarcoplasmic reticulum
Correct Answer: Transverse tubules
Explanation:When the concentration of intracellular Ca2+rises, muscle contraction occurs. The pathway of an action potential is down tube-shaped invaginations of the sarcolemma called T-tubules (transverse tubules). These penetrate throughout the muscle fibre and lie adjacent to the terminal cisternae of the sarcoplasmic reticulum. The voltage changes in the T-tubules result in the opening of sarcoplasmic reticulum Ca2+channels and there is there is release of stored Ca2+into the sarcoplasm. Thus muscle contraction occurs via excitation-contraction coupling (ECC) mechanism.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 147
Correct
-
Which of the following nerves provides cutaneous innervation to the posterior surface of the scrotum?
Your Answer: Branch of the perineal nerve
Explanation:The following nerves provide cutaneous innervation to the scrotum, and other anatomic structures:
The perineal nerve supplies the muscles in the urogenital triangle, and the skin on the posterior surface of the scrotum (or labia majora).
The genital branch of the genitofemoral nerve supplies the cremaster muscle, the skin over the anterior surface of the thigh, and the anterolateral surface of the scrotum.
The ilioinguinal nerve supplies the external oblique, internal oblique, transversus abdominis, skin of the upper medial aspect of thigh, the root of the penis and the anterior surface of the scrotum in the male, and the mons pubis and labia majora in the female.
The posterior cutaneous nerve of the thigh, or posterior femoral cutaneous nerve, supplies the skin over the lower medial quadrant of the buttock, the inferior skin of the scrotum or labium majus, and the back of the thigh and the upper part of the leg.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 148
Incorrect
-
Naloxone is a reversal agent for which of the following groups of drugs:
Your Answer: Depolarising muscle relaxants.
Correct Answer: Opioids
Explanation:Naloxone is a specific antagonist of mu(μ)-opioid receptors, the specific antidote for opioid overdose and will reverse respiratory depression and coma if given at sufficient dosage. The initial dose is usually 0.8 mg (2 mL) intravenously (the dose range suggested by BNF is 0.4-2 mg). It can also be given by intramuscular injection if the intravenous route is not feasible.
As naloxone has a shorter duration of action than most opioids, close monitoring and repeated injections are necessary according to the respiratory rate and depth of coma. The dose is generally repeated every 2-3 minutes to a maximum of 10 mg. When repeated doses are needed, naloxone may be given by a continuous infusion adjusted according to the vital signs. Initially, the infusion rate can be set at 60% of the initial resuscitative IV dose per hour.
In opioid addicts, naloxone administration may precipitate a withdrawal syndrome with abdominal cramps, nausea and diarrhoea, but these usually settle within 2 hours. -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 149
Incorrect
-
Which of the following occurs primarily to produce passive expiration:
Your Answer: Relaxation of internal and innermost intercostal muscles
Correct Answer: Relaxation of diaphragm and external intercostal muscles
Explanation:Passive expiration is produced primarily by relaxation of the inspiratory muscles (diaphragm and external intercostal muscles) and the elastic recoil of the lungs. In expiration, depression of the sternal ends of the ribs (‘pump handle’ movement), depression of the lateral shafts of the ribs (‘bucket handle’ movement) and elevation of the diaphragm result in a reduction of the thorax in an anteroposterior, transverse and vertical direction respectively. This results in a decreased intrathoracic volume and increased intrathoracic pressure and thus air is forced out of the lungs.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 150
Incorrect
-
Which of the following is NOT a notifiable disease:
Your Answer: Scarlet fever
Correct Answer: HIV
Explanation:HIV mainly infects CD4+ T helper cells. Viral replication results in progressive T-cell depletion and impaired cell-mediated immunity with subsequent secondary opportunistic infections and increased risk of malignancy. B-cell function is also reduced as a result of lack of T-cell stimulation.
HIV is not a notifiable disease. -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 151
Incorrect
-
Approximately how long is the duration of a lidocaine block (when given with adrenaline):
Your Answer: 30 minutes
Correct Answer: 90 minutes
Explanation:Lidocaine is a tertiary amine that is primarily used as a local anaesthetic but can also be used intravenously in the treatment of ventricular dysrhythmias.
Lidocaine works as a local anaesthetic by diffusing in its uncharged base form through neural sheaths and the axonal membrane to the internal surface of the cell membrane sodium channels. Here it alters signal conduction by blocking the fast voltage-gated sodium channels. With sufficient blockage, the membrane of the postsynaptic neuron will not depolarise and will be unable to transmit an action potential, thereby preventing the transmission of pain signals.
Each 1 ml of plain 1% lidocaine solution contains 10 mg of lidocaine hydrochloride. The maximum safe dose of plain lidocaine is 3 mg/kg. When administered with adrenaline 1:200,000, the maximum safe dose is 7 mg/kg. Because of the risk of vasoconstriction and tissue necrosis, lidocaine should not be used in combination with adrenaline in extremities such as fingers, toes, and the nose.
The half-life of lidocaine is 1.5-2 hours. Its onset of action is rapid within a few minutes, and it has a duration of action of 30-60 minutes when used alone. Its duration of action is prolonged by co-administration with adrenaline (about 90 minutes).
Lidocaine tends to cause vasodilatation when used locally. This is believed to be due mainly to the inhibition of action potentials via sodium channel blocking in vasoconstrictor sympathetic nerves. -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 152
Incorrect
-
You are attending to a patient that has presented with a severe headache in the Emergency Department. The patient has signs of cerebral oedema and raised intracranial pressure.
You discuss the case with the on-call neurology registrar and decide to prescribe Mannitol. The nurse assisting you asks you to reconsider this management plan as she suspects the patient has a contraindication to Mannitol.
Out of the following, what is a contraindication to mannitol?Your Answer: Hypokalaemia
Correct Answer: Severe cardiac failure
Explanation:Mannitol is the most widely used osmotic diuretic that is most commonly used to reduce cerebral oedema and intracranial pressure.
It is recommended to use mannitol for the reduction of CSF pressure/cerebral oedema in a dose of 0.25-2 g/kg as an intravenous infusion over 30-60 minutes. This can be repeated 1-2 times after 4-8 hours if needed.Mannitol has several contraindications and some of them are listed below:
1. Anuria due to renal disease
2. Acute intracranial bleeding (except during craniotomy)
3. Severe cardiac failure
4. Severe dehydration
5. Severe pulmonary oedema or congestion
6. Known hypersensitivity to mannitol -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 153
Incorrect
-
A patient suffers a stab wound to the neck. The entry point of the blade is situated within the anterior triangle of the neck.
Which of the following muscles is most likely to be involved? Select ONE answer only.Your Answer: Levator scapulae
Correct Answer: Sternothyroid
Explanation:The anterior triangle is the triangular area of the neck found anteriorly to the sternocleidomastoid muscle. It is formed by the anterior border of sternocleidomastoid laterally, the median line of the neck medially and by the inferior border of the mandible superiorly. The apex of the anterior triangle extends towards the manubrium sterni. The anterior triangle contains:
Muscles: thyrohyoid, sternothyroid, sternohyoid muscles
Organs: thyroid gland, parathyroid glands, larynx, trachea, esophagus, submandibular gland, caudal part of the parotid gland
Arteries: superior and inferior thyroid, common carotid, external carotid, internal carotid artery (and sinus), facial, submental, lingual arteries
Veins: anterior jugular veins, internal jugular, common facial, lingual, superior thyroid, middle thyroid veins, facial vein, submental vein, lingual veins
Nerves: vagus nerve (CN X), hypoglossal nerve (CN XII), part of sympathetic trunk, mylohyoid nerveThe posterior triangle is a triangular area found posteriorly to the sternocleidomastoid muscle. It has three borders; anterior, posterior and inferior borders. The anterior border is the posterior margin of the sternocleidomastoid muscle. The posterior border is the anterior margin of the trapezius muscle, while the inferior border is the middle one-third of the clavicle. The investing layer of deep cervical fascia and integument forms the roof of the space, while the floor is covered with the prevertebral fascia along with levator scapulae, splenius capitis and the scalene muscles. The inferior belly of omohyoid subdivides the posterior triangle into a small supraclavicular, and a large occipital, triangle.
Contents:
Vessels: the third part of the subclavian artery, suprascapular and transverse cervical branches of the thyrocervical trunk, external jugular vein, lymph nodes
Nerves: accessory nerve (CN XI), the trunks of the brachial plexus, fibers of the cervical plexus -
This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 154
Incorrect
-
A 40-year-old male presents to your clinic complaining of a cough with bloody sputum for the past three months. He has also had fever, night sweats, and has noticed some weight loss over the past three months.
Which ONE of the following statements regarding this disease is correct?Your Answer: Tuberculosis is spread by the faeco-oral route
Correct Answer: It can be diagnosed using the Ziehl-Neelson stain
Explanation:Tuberculosis is an infection caused by the microorganism Mycobacterium tuberculosis. TB can affect any organ system in the body, but it most commonly affects the lungs, followed by the lymph nodes.
Option Tuberculosis is spread by the faecal-oral route: It is spread by inhalation of droplet nuclei.
There are different methods to diagnose a tuberculosis infection.
1) Direct Microscopy: The organisms are visualised using Ziehl-Neelsen or Auramine staining. This is the quickest method to establish a diagnosis and start treatment.
2) Culture: M. tuberculosis can be grown on Lowenstein-Jensen or Ogawa mediums, but it can take up to 8 weeks; therefore, ZN staining is also performed to start treatment immediately.Option There are several types of vaccine currently available: The BCG vaccine is the only vaccine approved to prevent TB and is administered at birth.
Option Miliary tuberculosis refers to tuberculosis that affects the spine: Miliary tuberculosis refers to a tuberculosis infection disseminated throughout the body’s organ systems via the blood or lymphatics. Pott’s disease is extrapulmonary TB that affects the spine. It usually affects the lower thoracic and upper lumbar regions.
Option A Ghon focus typically appears at the apex of a lung: The Ghon focus is a primary sign of TB that forms in the lung of previously unaffected patients. It typically occurs in the mid or lower zones of the lung.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 155
Incorrect
-
Which patients are particularly susceptible to infection with herpes simplex, those with:
Your Answer: Reduced liver function
Correct Answer: T-cell deficiency
Explanation:Cell-mediated immunity, especially the action of cytotoxic T-cells, is essential in the control of herpesvirus infections and patients with T-cell deficiency are at particular risk of reactivation and severe infection. T-cell deficiency may follow HIV infection, chemotherapy, corticosteroid therapy or organ transplantation.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 156
Incorrect
-
Where on the body is the radial artery pulsation best palpated?
Your Answer: At the wrist just lateral to the palmaris longus tendon
Correct Answer: At the wrist just lateral to the flexor carpi radialis tendon
Explanation:The radial artery lies lateral to the large tendon of the flexor carpi radialis muscle and anterior to the pronator quadratus at the distal end of the radius. The flexor carpi radialis muscle is used as a landmark in locating the pulse.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 157
Incorrect
-
A 68-year-old female has presented to the Emergency Department with chest pain, palpitations, and breathlessness complaints. On ECG, she is diagnosed with ventricular arrhythmia and is administered lidocaine.
Which of the following is the correct mechanism of action of lidocaine?Your Answer: Opens K + channels in the heart
Correct Answer: Blocks Na+ channels in the heart
Explanation:Lidocaine is a tertiary amide local anaesthetic and also a class IV antiarrhythmic.
Like other local anaesthetics, lidocaine works on the voltage-gated sodium ion channel on the nerve cell membranes. It works in the following steps:
1. diffuses through neural sheaths and the axonal membrane into the axoplasm
2. binds fast voltage-gated Na+ channels in the neuronal cell membrane and inactivates them
3. With sufficient blockage, the membrane of the postsynaptic neuron will not depolarise and will be unable to transmit an action potential, thereby preventing the transmission of pain signalsThe same principle applies to Lidocaine’s actions in the heart as it blocks the sodium channels in the conduction system and the myocardium. This raises the threshold for depolarizing, making it less likely for the heart to initiate or conduct any action potential that can cause arrhythmia.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 158
Correct
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A 25-year-old guy who has had a knee-high plaster cast on his left leg for the past 5 weeks arrives at the emergency department complaining of numbness on the dorsum of his left foot and an inability to dorsiflex or evert his foot. You know that his symptoms are due to fibular nerve compression. Where is the fibular nerve located?
Your Answer: Neck of fibula
Explanation:Dorsiflexion and eversion of the foot are innervated by the deep fibular nerve and the superficial fibular nerve, respectively.
The common fibular nerve runs obliquely downward along the lateral border of the popliteal fossa (medial to the biceps femoris) before branching at the neck of the fibula.
Thus, it is prone to being affected during an impact injury or fracture to the bone or leg. Casts that are placed too high can also compress the fibular nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 159
Incorrect
-
A 23-year-old man is discovered to have an infection from Helicobacter pylori.
Which of the following types of cancer is mostly associated with Helicobacter pylori infection?Your Answer: Colon cancer
Correct Answer: Gastric cancer
Explanation:H. pylori is recognized as a major cause of type B gastritis, a chronic condition formerly associated primarily with stress and chemical irritants. In addition, the strong association between long-term H. pylori infection and gastric cancer has raised more questions regarding the clinical significance of this organism. There is speculation that long-term H. pylori infection resulting in chronic gastritis is an important risk factor for gastric carcinoma resulting in H. pylori being classified as a carcinogen.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 160
Incorrect
-
Regarding the trachea, which of the following statements is INCORRECT:
Your Answer: The trachea lies directly anterior to the oesophagus.
Correct Answer: A cricothyrotomy involves making an opening in the neck inferior to the cricoid cartilage.
Explanation:A cricothyrotomy involves making an opening in the median cricothyroid ligament (the medial part of the cricothyroid membrane), between the cricoid cartilage below and the thyroid cartilage above.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 161
Incorrect
-
Atrial natriuretic peptide (ANP) is primarily produced in response to:
Your Answer: An increase in Na+ concentration
Correct Answer: An increase in intravascular fluid volume
Explanation:Atrial natriuretic peptide (ANP) is released from cardiac atrial muscle cells in response to atrial stretch caused by an increase in intravascular fluid volume and is also produced in collecting duct cells.
Atrial natriuretic peptide acts to inhibit sodium reabsorption in the distal nephron. -
This question is part of the following fields:
- Physiology
- Renal
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Question 162
Correct
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You suspected a fungal nail infection in a 50-year-old man who presented with an itchy, scaly rash between his toes and a thicker, discoloured nail on his big toe that has been there for almost one month already. Which of the following tests is most likely to confirm your suspected diagnosis?
Your Answer: Nail clippings for microscopy and culture
Explanation:Nail clippings for microscopy and culture are a diagnostic test for fungal infection. Because some fungi are restricted to the lower parts of the nail, clippings should be taken from the discoloured or brittle parts and cut back as far as possible from the free edge.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 163
Incorrect
-
A 64-year-old man presents with an acute episode of gout. He has a history of chronic heart failure and hypertension. His current medications include ramipril and furosemide.
Which of the following statements regarding the treatment of gout is true? Select ONE answer only.Your Answer: NSAIDs are the treatment of choice for patients with a history of heart failure
Correct Answer: Colchicine has a role in prophylactic treatment
Explanation:In the absence of any contra-indications, high-dose NSAIDs are the first-line treatment for acute gout. Naproxen 750 mg as a stat dose followed by 250 mg TDS is a commonly used and effective regime.
Aspirin should not be used in gout as it reduces the urinary clearance of urate and interferes with the action of uricosuric agents. Naproxen, Diclofenac or Indomethacin are more appropriate choices.
Allopurinol is used prophylactically, preventing future attacks by reducing serum uric acid levels. It should not be started in the acute phase as it increases the severity and duration of symptoms.
Colchicine acts on the neutrophils, binding to tubulin to prevent neutrophil migration into the joint. It is as effective as NSAIDs in relieving acute attacks. It also has a role in prophylactic treatment if Allopurinol is not tolerated.
NSAIDs are contra-indicated in heart failure as they can cause fluid retention and congestive cardiac failure. Colchicine is the preferred treatment in patients with heart failure or those who are intolerant of NSAIDs. -
This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 164
Incorrect
-
An very unwell patient is receiving treatment in your hospital's HDU and is found to have an Escherichia coli O157 infection.
Which one of these statements about Escherichia coli O157 is true?Your Answer: It is enteroaggregative
Correct Answer: Haemolytic uraemic syndrome develops in approximately 6% of patients
Explanation:Escherichia coli O157 is a serotype of Escherichia coli.
The Escherichia coliO157 strain is ‘enterohaemorrhagic’ and causes severe forms of acute haemorrhagic diarrhoea. It can also cause non-haemorrhagic diarrhoea.Incubation period of Escherichia coli O157 is usually 3-4 days and bloody diarrhoea usually begins on the 3rd or 4th day of the infection.
Infections with Escherichia coliO157 are more common during the warmer months than in winter.
Haemolytic uraemic syndrome develops in approximately 6% of patients. It is commonly seen in children and in the elderly.
Escherichia coli O157 can also cause:
Haemorrhagic colitis
Haemolytic uraemic syndrome
Thrombotic thrombocytopenic purpura but not immune thrombocytopenic purpura. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 165
Correct
-
An analytical cohort study is done to compare the relationship between omega 3 intake and occurrence of myocardial infarction (MI) among males aged over 65 years. The following are the data from the study:
No. of subjects taking placebo: 100 men
No. of subjects taking placebo who suffered an MI: 15 men
No. of subjects taking omega 3: 100 men
No. of subjects taking omega 3 who suffered an MI: 5 men
Compute for the absolute risk in the treatment (omega 3) group.Your Answer: 0.05
Explanation:The absolute risk (AR) is the probability or chance of an event. It is computed as the number of events in treated or control groups, divided by the number of people in that group.
AR = 5/100 = 0.05
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This question is part of the following fields:
- Evidence Based Medicine
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Question 166
Incorrect
-
Which of the following clinical features would you least expect to see in a lesion of the frontal lobe:
Your Answer: Incontinence
Correct Answer: Contralateral homonymous hemianopia with macular sparing
Explanation:Contralateral homonymous hemianopia with macular sparing results from damage to the primary visual cortex of the occipital lobe. Incontinence may occur due to damage of the cortical micturition centre in the prefrontal cortex. Primitive reflexes and inability to problem solve may occur due to damage to the prefrontal cortex. Motor weakness of the contralateral limb with UMN signs may occur due to damage of the primary motor cortex.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 167
Incorrect
-
A patient suffered from a chest injury while working out in the gym. As a consequence of his injury, his pectoralis minor muscle was damaged.
Which of the following statements regarding the pectoralis minor muscle is considered correct?Your Answer: It flexes the humerus
Correct Answer: It stabilises the scapula
Explanation:The pectoralis minor, in comparison to the pectoralis major, is much thinner and triangular in shape and resides below the major. It originates from the margins of the third to fifth ribs adjacent to the costochondral junction. The fibres consequently pass upward and laterally to insert into the medial border and superior surface of the coracoid process. It is crucial in the stabilization of the scapula by pulling it downward and anteriorly against the thoracic wall.
Arterial supply to the pectoralis minor also derives from the pectoral branch of the thoracoacromial trunk. Nerve supply of the pectoralis minor is a function of the lateral pectoral nerve and the medial pectoral nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 168
Incorrect
-
Anatomical barriers to infection include all of the following EXCEPT:
Your Answer: Irritant receptors causing the cough reflex
Correct Answer: Mucociliary escalator in the gastrointestinal tract
Explanation:Anatomical barriers to infection include:tight junctions between cells of the skin and mucosal membranesthe flushing action of tears, saliva and urinethe mucociliary escalator in the respiratory tract (together with the actions of coughing and sneezing)the acidic pH of gastric and vaginal secretionsthe acidic pH of the skin (maintained by lactic acid and fatty acids in sebum)enzymes such as lysozyme found in saliva, sweat and tearspepsin present in the stomachbiological commensal flora formed on the skin and the respiratory, gastrointestinal and genitourinary tracts which protect the host by competing with pathogenic bacteria for nutrients and attachment sites and by producing antibacterial substances
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This question is part of the following fields:
- Microbiology
- Principles
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Question 169
Incorrect
-
Funnel plots are typically used to display:
Your Answer: The strength of evidence of constituent trials in a meta-analysis
Correct Answer: The existence of publication bias in meta-analysis
Explanation:Funnel plots are used to demonstrate the existence of publication bias in meta-analysis. Funnel plots are scatter plots of treatment effects estimated from individual studies on the x axis and some measure of study size on the y axis. Each point on the graph represents one of the studies. A symmetrical inverted funnel shape indicates an absence of publication bias. If there is publication bias, there will be asymmetry of the open wide end due to the absence of small negative results.
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This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
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Question 170
Incorrect
-
Which of the following neurotransmitter and receptor combinations is present at the neuromuscular junction:
Your Answer: Noradrenaline acting at alpha receptors
Correct Answer: Acetylcholine acting at nicotinic receptors
Explanation:At the neuromuscular junction, acetylcholine is released from the prejunctional membrane which acts on cholinergic nicotinic receptors on the postjunctional membrane.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 171
Incorrect
-
A study investigating the risk of suffering a stroke in patients with atrial fibrillation taking the new antiplatelet drug ticagrelor, compared with standard treatment with warfarin is done over a 2-year time period. 30 of the 300 patients taking ticagrelor and 20 of the 500 patients taking warfarin suffered a stroke over the 2-year period.
One of these statements is true regarding the outcomes of this study.
Your Answer: Ticagrelor has no effect on stroke
Correct Answer: Ticagrelor increases the risk of stroke
Explanation:Absolute risk and relative risk are used to assess the strength of a relationship between a disease and a factor that may affect it.
Absolute risk (AR) is the risk of developing a disease over a time period:
AR = the number of events that occur in a group / number of people in that groupThe absolute risk reduction (ARR) is the difference between the absolute risk in the control group (ARC) and the absolute risk in the treated group (ART).
ARR = ARC – ART
The control group is the warfarin group, therefore the ARC is 20/500 (0.04).
Treatment group is the ticagrelor group and ART = 30/300 (0.1).ARR = 0.04 – 0.1 = -0.06. This shows that treatment with ticagrelor increases risk of developing stroke. This is also termed a relative risk increase.
Relative risk, or risk ratio, (RR) is used to compare the risk in the two different groups. It is the ratio of the absolute risks of the disease in the treatment group (ART) to the absolute risk of the disease in the control group (ARC):
RR=ART /ARCTherefore RR = 0.1 / 0.04 = 2.5
RR < 1 means the intervention reduces the risk of the outcome being studied
RR = 1 means the treatment has no effect on the outcome being studied
RR > 1 means the intervention increased the risk of the outcome being studied
Since RR is 2.5, ticagrelor increases the risk of stroke.SUMMARY
Absolute risk reduction is -0.06
Absolute risk in warfarin group = 0.04
Relative risk = 2.5
Ticagrelor has no effect on stroke is incorrect because RR is not =1 -
This question is part of the following fields:
- Evidence Based Medicine
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Question 172
Incorrect
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Question 173
Incorrect
-
Through which of the following anatomical structures does an indirect inguinal hernia pass?
Your Answer: Pyramidalis
Correct Answer: External oblique
Explanation:Inguinal hernias are subdivided into direct and indirect.
An indirect hernia occurs when abdominal contents protrude through the internal inguinal ring and into the inguinal canal. This occurs lateral to the inferior epigastric vessels. The hernia contents may extend into the scrotum.
A direct inguinal hernia is protrusion of abdominal contents through the transversalis fascia within Hesselbach’s triangle. The borders of Hesselbach’s triangle are the inferior epigastric vessels superolaterally, the rectus sheath medially, and inguinal ligament inferiorly.
The deep (internal) inguinal ring is located above and halfway between the pubic tubercle and the anterior superior iliac spine. This serves as the entrance to the inguinal canal. The superficial (external) inguinal ring lies immediately above and medial to the pubic tubercle. This triangular opening is a defect in the external oblique aponeurosis, and forms the exit of the inguinal canal.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 174
Correct
-
Adenosine is primarily indicated for which of the following:
Your Answer: Paroxysmal supraventricular tachycardia
Explanation:Adenosine is usually the treatment of choice for terminating paroxysmal supraventricular tachycardia including those associated with accessory conduction pathways e.g. Wolff-Parkinson-White syndrome.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 175
Incorrect
-
A 29 year old patient with known inflammatory bowel disease presents to ED with surgical complications following his recent ileocaecal resection. Removal of the terminal ileum may result in the malabsorption of which of the following:
Your Answer: Vitamin D
Correct Answer: Vitamin B12
Explanation:On ingestion, vitamin B12 is bound to R protein found in saliva and gastric secretions, which protects it from digestion in the stomach. Intrinsic factor is secreted by gastric parietal cells. Receptors for the IF-B12 complex are present in the membrane of epithelial cells of the terminal ileum, which bind the complex and allow uptake of vitamin B12 across the apical membrane by endocytosis. Vitamin B12 is then transported across the basal membrane into the portal blood where it is bound to transcobalamin II and processed by the liver. In pernicious anaemia, there are autoantibodies against gastric parietal cells and intrinsic factor, resulting in vitamin B12 deficiency anaemia.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 176
Incorrect
-
Which of the following antibiotics may be used for malaria prophylaxis:
Your Answer: Azithromycin
Correct Answer: Doxycycline
Explanation:Doxycycline may be used for malaria prophylaxis and as an adjunct to quinine in the treatment of Plasmodium falciparum malaria.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 177
Incorrect
-
The risk of renal impairment in a patient on ACE inhibitor therapy is increased by concomitant treatment with which of the following drug classes:
Your Answer: Statins
Correct Answer: NSAIDs
Explanation:Concomitant treatment with NSAIDs increases the risk of renal damage, and with potassium-sparing diuretics (or potassium-containing salt substitutes) increases the risk of hyperkalaemia. Hyperkalaemia and other side effects of ACE inhibitors are more common in the elderly and in those with impaired renal function and the dose may need to be reduced.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 178
Incorrect
-
A 27-year-old man was sent to the emergency department by ambulance with suspected anaphylaxis. What is the best first-line treatment for this patient?
Your Answer: 5 mg of adrenaline intramuscularly
Correct Answer: 500 micrograms of adrenaline intramuscularly
Explanation:Anaphylaxis is the sudden onset of systemic hypersensitivity due to IgE-mediated chemical release from mast cells and basophils.
If anaphylaxis is suspected, 500 micrograms of adrenaline should be administered promptly (0.5 ml of 1:1000 solution).
In anaphylaxis, the intramuscular route is the most immediate approach; the optimal site is the anterolateral aspect of the middle part of the thigh.
Intravenous adrenaline should only be given by people who are well-versed in the use and titration of vasopressors in their routine clinical practice.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 179
Correct
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Which of the following data types does a pain-scoring system represent?
Your Answer: Ordinal
Explanation:Pain scoring systems are processes for assessing pain and the severity of illnesses that have been scientifically designed and tested. An example of ordinal categorical data is a pain scoring system.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 180
Incorrect
-
A 57-year-old woman has presented with cough and shortness of breath. Her GP had done some blood tests recently and told her that she had a positive ANA result.
Which of these statements is true about anti-nuclear antibodies (ANAs)? Select only ONE answer.
Your Answer: Speckled staining is suggestive of lupus
Correct Answer: The presence of ANAs in rheumatoid arthritis is suggestive of Felty’s syndrome
Explanation:Anti-nuclear antibodies are auto-antibodies directed against a variety of nuclear antigens. There are different staining patterns and each pattern is suggestive of a different disorder.
Speckled staining is suggestive of mixed connective tissue disease.
Nucleolar staining is suggestive of scleroderma, while homogenous staining is suggestive of lupus.
Anti-double stranded DNA is suggestive of SLE while anti-histone antibodies are suggestive of drug-induced lupus.
ELISA testing is cheaper but not the most accurate means of testing for ANAs. Indirect immunofluorescence testing is the most accurate.
The presence of ANAs in rheumatoid arthritis is suggestive of Felty’s syndrome. Felty’s syndrome is characterized by a combination of rheumatoid arthritis, splenomegaly and neutropenia.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 181
Incorrect
-
A 75-year-old man with rheumatoid arthritis had gained weight, developed resistant hypertension, muscle weakness, and ankle oedema. This patient is most likely suffering from what condition?
Your Answer: Renal artery stenosis
Correct Answer: Cushing's syndrome
Explanation:Overuse of cortisol medication, as seen in the treatment of patients with chronic asthma or rheumatoid arthritis, can cause Cushing’s syndrome.
Weight gain, thin arms and legs, a round face, increased fat around the base of the neck, a fatty hump between the shoulders, easy bruising, wide purple stretch marks primarily on the abdomen, breasts, hips, and under the arms, weak muscles, hirsutism, hypertension, erectile dysfunction, osteoporosis, frontal alopecia, acne, depression, poor wound healing, and polycythaemia are all clinical features of Cushing’s syndrome.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 182
Correct
-
Which statement regarding skeletal muscle is true?
Your Answer: Myosin is the major constituent of the thick filament
Explanation:Myosin is the major constituent of the thick filament.
Actin is the major constituent of the THIN filament.
Thin filaments consist of actin, tropomyosin and troponin in the ratio 7:1:1.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 183
Incorrect
-
The following structures all lie anteriorly to the oesophagus EXCEPT for the:
Your Answer: Pericardium
Correct Answer: Thoracic duct
Explanation:Posterior to the oesophagus, the thoracic duct is on the right side inferiorly but crosses to the left more superiorly (at T5).
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 184
Correct
-
A 55 year old man presents to ED complaining of leg weakness. Your colleague has examined the patient and suspects femoral nerve palsy. Which of the following clinical features would you LEAST expect to see on examination of this patient:
Your Answer: Weakness of hip extension
Explanation:Damage to the femoral nerve results in weakness of hip flexion and knee extension and loss of sensation over the anterior thigh and the anteromedial knee, medial leg and medial foot.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 185
Correct
-
A 32-year-old woman presents with abdominal pain and bloody diarrhoea that has been going on for 3 days.
Among the following microorganisms, which is considered to be a cause of infectious bloody diarrhoea?Your Answer: Entamoeba histolytica
Explanation:The following are organisms that are capable of producing acute, bloody diarrhoea:
– Campylobacter jejuni
– Escherichia coli O157:H7
– Salmonella species
– Shigella species
– Yersinia species
– Entamoeba histolyticaOther E. coli strains, Giardia, Vibrio, and other parasites are associated with watery, but not bloody, diarrhoea.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 186
Incorrect
-
Which of the following statements is correct regarding the partial pressure of oxygen during respiration?
Your Answer: Alveolar PO 2 > Inhaled PO 2
Correct Answer: Exhaled PO 2 > Alveolar PO 2
Explanation:Because of humidification, inspired PO2 in the airways is less than inhaled PO2.
Because of gas exchange, alveolar PO2 is less than inhaled or inspired PO2.
Because of mixing with anatomical dead space (air that has not taken part in gas exchange, exhaled PO2 is greater than alveolar O2, and therefore that has relatively higher PO2 on the way out, but is less than inhaled or inspired PO2.
Typical values for a resting young healthy male (in kPa) are shown below:
-Inhaled air: PO221.2, PCO20.0
-Inspired air in airways (after humidification): PO219.9, PCO20.0
-Alveolar air (after equilibrium with pulmonary capillaries): PO213.3, PCO25.3
-Exhaled air (after mixing with anatomical dead space air): PO215.5, PCO24.3 -
This question is part of the following fields:
- Physiology
- Respiratory
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Question 187
Incorrect
-
The qSOFA score is a bedside prompt designed to identify patients with suspected infection who are at greater risk for a poor outcome outside of the intensive care unit.
Which of the following is one of the criteria used in the qSOFA score? Select ONE answer only.Your Answer: Diastolic blood pressure <60 mmHg
Correct Answer: Respiratory rate >22
Explanation:In February 2016 the Society of Critical Care Medicine published a JAMA article reformatting the definitions of sepsis in an attempt to overcome the shortcomings of the old definitions.
The main changes are a new definition of sepsis, the replacement of the SIRS criteria with the quick Sepsis-related Organ Failure Assessment (qSOFA), and the complete removal of “severe sepsis” as an entity.
The new definition of sepsis is that it is “life-threatening organ dysfunction caused by a dysregulated host response to infection.”
Septic shock is “a subset of sepsis in which underlying circulatory and cellular metabolism abnormalities are profound enough to increase mortality.”
In essence this means that septic shock is sepsis plus the following, despite adequate fluid resuscitation:
Vasopressors required to maintain a MAP > 65 mmHg
Serum lactate > 2 mmol/l
The qSOFA score is a bedside prompt designed to identify patients with suspected infection who are at greater risk for a poor outcome outside of the intensive care unit. It uses the following three criteria:
Hypotension (SBP < 100 mmHg)
Tachypnoea (RR > 22)
Altered mental status (GCS < 15)
The presence of 2 or more of the qSOFA criteria near the onset of infection is associated with greater risk of death or a prolonged intensive care unit stay. -
This question is part of the following fields:
- Pathology
- Pathology Of Infections
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Question 188
Incorrect
-
A 32 year old woman presents with episodes of flushing, headaches and palpitations. On examination her blood pressure is significantly elevated. Which of the following is the most likely diagnosis:
Your Answer: Cushing's disease
Correct Answer: Pheochromocytoma
Explanation:Phaeochromocytomas are catecholamine-secreting tumours which occur in about 0.1% of patients with hypertension. In about 90% of cases they arise from the adrenal medulla. The remaining 10%, which arise from extra-adrenal chromaffin tissue, are termed paragangliomas. Common presenting symptoms include one or more of headache, sweating, pallor and palpitations. Less commonly, patients describe anxiety, panic attacks and pyrexia. Hypertension, whether sustained or episodic, is present in at least 90% of patients. Left untreated phaeochromocytoma can occasionally lead to hypertensive crisis, encephalopathy, hyperglycaemia, pulmonary oedema, cardiac arrhythmias, or even death.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 189
Correct
-
Regarding Clostridium perfringens, which of the following statements is CORRECT:
Your Answer: It can cause exotoxin-mediated food poisoning.
Explanation:Clostridium perfringens is an obligate anaerobe and has exotoxin mediated effects. It is the most common cause of gas gangrene. C. perfringens is also implicated in food poisoning, cellulitis, enteritis necrotican (life-threatening infection involving ischaemic necrosis of the jejunum), and rarely, CNS infections such as meningitis and encephalitis.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 190
Incorrect
-
The neurotransmitter in the synaptic cleft is either eliminated or deactivated after the postsynaptic cell responds to the neurotransmitter.
Which of the following enzymes catalyses the breakdown of noradrenaline?Your Answer: Gamma-aminobutyric acid (GABA)
Correct Answer: Catechol-O-methyltransferase (COMT)
Explanation:The neurotransmitter in the synaptic cleft is either eliminated or deactivated after the post-synaptic cell responds to the neurotransmitter.
This can be accomplished in a variety of ways:
Re-uptake
Breakdown
DiffusionSerotonin is an example of a neurotransmitter that is uptake. Serotonin is absorbed back into the presynaptic neuron via the serotonin transporter (SERT), which is found in the presynaptic membrane. Re-uptake neurotransmitters are either recycled by repackaging into vesicles or broken down by enzymes.
Specific enzymes found in the synaptic cleft can also break down neurotransmitters. The following enzymes are examples of these enzymes:
Acetylcholinesterase (AChE) catalyses the acetylcholine breakdown (ACh)
The enzyme catechol-O-methyltransferase (COMT) catalyses the breakdown of catecholamines like adrenaline , dopamine and noradrenaline.The breakdown of catecholamines, as well as other monoamines like serotonin, tyramine, and tryptamine, is catalysed by monoamine oxidases (MOA).
Diffusion of neurotransmitters into nearby locations can also be used to eliminate them. -
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 191
Incorrect
-
Regarding the glomerular filtration barrier, which of the following statements is CORRECT:
Your Answer: The solution that is filtered into the Bowman's capsule is called ultraplasma.
Correct Answer: The main factor determining whether a substance is filtered or not is molecular weight.
Explanation:Molecular weight is the main factor in determining whether a substance is filtered or not – molecules < 7 kDa in molecular weight are filtered freely e.g. glucose, amino acids, urea, ions but larger molecules are increasingly restricted up to 70 kDa, above which filtration is insignificant. Negatively charged molecules are further restricted, as they are repelled by negative charges, particularly in the basement membrane. Albumin has a molecular weight of 69 kDa and is negatively charged, thus only very small amounts are filtered (and all of the filtered albumin is reabsorbed in the proximal tubule), whereas small molecules such as ions, glucose, amino acids and urea pass the filter without hindrance. This means that ultrafiltrate is virtually protein free, but otherwise has an identical composition of that of plasma. The epithelial lining of the Bowman's capsule consists of a single layer of cells called podocytes. The glomerular capillary endothelium is perforated by pores (fenestrations) which allow plasma components with a molecular weight of < 70 kDa to pass freely.
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This question is part of the following fields:
- Physiology
- Renal
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Question 192
Incorrect
-
What is the primary route of transmission of Norovirus?
Your Answer: Direct skin contact
Correct Answer: Oral-faecal route
Explanation:Norovirus is spread primarily by faecal-oral contact, but it can also be spread through contact with an infected person, ingestion of contaminated food or water, or contact with contaminated surfaces or items.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 193
Incorrect
-
A 15-year-old boy was brought to the emergency room with complaints of a headache, stiffness of the neck, and photophobia. Upon observation, the following were noted: HR 124, BP 86/43, RR 30, SaO 95%, temperature 39.5 deg C. A recently developed non-blanching rash on his legs was also observed.
What is most likely the causative agent of the case presented above?Your Answer: Neisseria meningitidis group A
Correct Answer: Neisseria meningitidis group B
Explanation:The meningococcus is solely a human pathogen, and up to 50% of the population may carry meningococci in the nasopharynx. Factors that lead to invasion and production of disease include complex inter-relationships of genetic predisposition, host status, environmental conditions, and virulence of the organism.
Meningococcal disease is the most common infectious cause of death in childhood in developed countries. It presents as septicaemia, meningitis, or a combination. Septicaemia is the more dangerous presentation, especially with septic shock; meningitis is more likely to lead to neurodevelopmental sequelae. Classic features of septicaemia are a non-blanching rash in a feverish, ill child.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 194
Incorrect
-
In a 7-year-old child with chickenpox, which of the following would you advise the mother NOT to do?
Your Answer: Use topical emollients to help ease the itching
Correct Answer: Give ibuprofen for the fever
Explanation:Chickenpox (varicella zoster) is a highly contagious airborne disease and has an incubation period of between 7-21 days. It often has a prodromal phase when there is a fever, aches and headaches, dry cough, and sore throat before onset of rash.
Some recognized complications of chickenpox are:
Orchitis
Hepatitis
Pneumonia
Encephalitis
Infected spots
Otitis media
Myocarditis
Glomerulonephritis
Appendicitis
PancreatitisTreatment is symptomatic and includes using paracetamol to manage fever. There is a link between use of ibuprofen in patients with chicken-pox and necrotizing fasciitis so Ibuprofen should NOT be used.
An emollient and antihistamine can be used to ease the itchy rash and oral hydration is encouraged.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 195
Incorrect
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You suspect an anaphylactic reaction in a patient who is hypotensive, with trouble breathing after eating peanuts. Which of the following diagnostic tests will confirm this?
Your Answer: Complement function assays
Correct Answer: Mast cell tryptase
Explanation:The concentration of serum tryptase rises in anaphylaxis and anaphylactoid responses.
Because tryptase is a significant component of mast cell granules, mast cell degranulation causes elevated tryptase levels in the blood.
Although tryptase levels are not always high during anaphylaxis, it is considered a particular marker.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 196
Correct
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At rest, saliva is produced predominantly by which of the following:
Your Answer: Submandibular gland
Explanation:At rest, most saliva is produced by the submandibular gland (65%). When stimulated by the autonomic nervous system, about 50% of saliva is produced by the parotid gland with only 30% produced by the submandibular gland.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 197
Incorrect
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A novel anti-tuberculosis medicine was compared to standard treatment and shown to cut the risk of death from 30 to 10 per 1000 people. How many patients would need to be treated (number need to treat (NNT)) in order to prevent 10 additional tuberculosis deaths:
Your Answer: 100
Correct Answer: 500
Explanation:The risk of mortality in the control group (usual therapy) minus the risk of death in the treatment group equals the absolute risk reduction (ARR) of treatment.
30/1000 minus 10/1000 = 20/1000 = 0.02NNT = 1/ARR = 1/0.02 = 50
As a result, 50 people would need to be treated in order to prevent one additional fatality, and 500 people would need to be treated in order to avoid 10 additional deaths. -
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 198
Incorrect
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A 25-year-old girl just got back from a trip to Northern India. She complains of headaches and intermittent fever. The fever starts with intense chills, then feels very hot, followed by profuse sweating. She is drowsy and is running a fever of 39.0°C. On examination, there are no palpable lymph nodes or rash seen. She has hepatosplenomegaly.
Which one of the following is the most likely diagnosis?Your Answer: Chagas disease
Correct Answer: Malaria
Explanation:Malaria is a protozoal infection of red blood cells and the liver. It is caused by the parasite belonging to the genus Plasmodium. It is transmitted by the female mosquito Anopheles.
Several species with distinct features:
P. vivax/P. ovale
P. malariae
P. falciparumThe common symptoms of malaria are:
Paroxysms of fever – a cyclical occurrence of:
1) a cold phase – the patient experiences intense chills
2) a hot stage – the patient feels extremely hot
3) a sweating stage – the fever declines and the patient sweats profusely
– Fever recurs at regular intervals (48hrs, 72hrs): Variable by species of PlasmodiumAnaemia (RBC infection)
– Severity varies by species of Plasmodium
– Haemolytic: sometimes jaundiceSplenomegaly
Also nonspecific symptoms:
– Sweating
– fatigue
– malaise
– arthralgias
– headache
– Sometimes cough, vomiting, diarrhoea -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 199
Incorrect
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The pathophysiology of Addison's disease is as follows:
Your Answer:
Correct Answer: Adrenocortical insufficiency
Explanation:Primary adrenal insufficiency, also known as Addison’s disease, occurs when the adrenal glands cannot produce an adequate amount of hormones despite a normal or increased corticotropin (ACTH) level.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 200
Incorrect
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The renal corpuscle, consisting of the Bowman's capsule and the glomerulus is found where in the kidney:
Your Answer:
Correct Answer: The cortex
Explanation:All nephrons have their renal corpuscles in the renal cortex. Cortical nephrons have their renal corpuscles in the outer part of the cortex and relatively short loops of Henle. Juxtamedullary nephrons have their corpuscles in the inner third of the cortex, close to the corticomedullary junction, with long loops of Henle extending into the renal medulla.
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This question is part of the following fields:
- Physiology
- Renal
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