-
Question 1
Incorrect
-
Fatigue, dizziness upon standing, muscle weakness, weight loss, nausea, and sweating are all symptoms that a patient may experience in Addison's disease.
Which of the following claims about Addison's disease is correct?Your Answer: Men are more commonly affected than women
Correct Answer: ACTH levels are elevated in primary insufficiency
Explanation:The adrenal glands produce too little steroid hormones, which causes Addison’s disease. The production of glucocorticoids, mineralocorticoids, and sex steroids are all altered. The most prevalent cause is autoimmune adrenalitis, which accounts for 70-80 percent of cases.
It affects more women than males and occurs most frequently between the ages of 30 and 50.
The following are some of the clinical signs and symptoms of Addison’s disease:
Weakness and sluggishness
Hypotension is a condition in which the blood pressure (notably orthostatic hypotension)
Vomiting and nausea
Loss of weight
Axillary and pubic hair loss
Depression
Hyperpigmentation is a condition in which a person’s (palmar creases, buccal mucosa and exposed areas more commonly affected)
The following are the classic biochemical hallmarks of Addison’s disease:
Hyponatraemia
Hyperkalaemia
Hypercalcaemia
Hypoglycaemia
Acidosis metabolica
When ACTH levels are combined with cortisol levels, it is possible to distinguish between primary and secondary adrenal insufficiency:
In primary insufficiency, levels rise.
In secondary insufficiency, levels are low or low normal. -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 2
Incorrect
-
A 30-year old male is brought to the emergency room after a terrible fall during a photoshoot. The patient reported falling on his right forearm. There is evident swelling and tenderness on the affected area, with notable weakness of the flexor pollicis longus muscle. Radiographic imaging showed a fracture on the midshaft of the right radius.
Which of the following nerves is most likely injured in the case above?Your Answer: The median nerve
Correct Answer: The anterior interosseous nerve
Explanation:Flexor pollicis longus receives nervous supply from the anterior interosseous branch of median nerve, derived from spinal roots C7 and C8.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 3
Incorrect
-
A 65-year-old female presents to the Emergency Department with complaints of chest pain pointing to angina. A dose of glyceryl trinitrate (GTN) was administered, rapidly resolving her symptoms. Unfortunately, she develops a side-effect of the drug.
Which one of the following is the side effect she is most likely to have developed?Your Answer: Syncope
Correct Answer: Flushing
Explanation:Angina pectoris is the most common symptom of ischemic heart disease and presents with chest pain relieved by rest and nitro-glycerine.
Nitrates are the first-line treatment to relieve chest pain caused by angina. The commonly used nitrates are:
1. Glyceryl trinitrate
2. Isosorbide dinitrateSide effects to nitrate therapy are common especially
The most common side effects are:
1. Headaches
2. Feeling dizzy, weak, or tired
3. Nausea
4. FlushingThe serious but less likely to occur side effects are:
1. Methemoglobinemia (rare)
2. Syncope
3. Prolonged bleeding time
4. Exfoliative dermatitis
5. Unstable angina
6. Rebound hypertension
7. ThrombocytopeniaDry eyes, bradycardia, and metabolic acidosis have not been reported.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 4
Incorrect
-
Which of the following is where the rectovesical fascia is located:
Your Answer: Between the rectum and the seminal vesicle
Correct Answer: Between the fundus of the bladder and the ampulla of the rectum
Explanation:In a triangular area between the vasa deferentia, the bladder and rectum are separated only by rectovesical fascia, commonly known as Denonvillier’s fascia.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 5
Correct
-
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: Escherichia coli
Explanation:E.Colistrain 0157 causes enterohaemorrhagic diarrhoea and can be followed by haemolytic uraemic syndrome (renal failure, haemolytic anaemia and thrombocytopenia).
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 6
Correct
-
A 12-year-old boy presents to the ED with symptoms suggesting an anaphylactic reaction.
Which of these statements about anaphylaxis is true?Your Answer: The immunoglobulin-antigen complex binds to Fc receptors on the surface of mast cells.
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.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 7
Correct
-
In the treatment of bradyarrhythmias with adverse characteristics or risk of asystole, what is the initial suggested dose of atropine?
Your Answer: 500 micrograms
Explanation:Atropine 500 mcg IV bolus should be administered if there are any adverse features or risk of asystole. If the reaction is not adequate, repeat the steps every 3 to 5 minutes up to a maximum dose of 3 mg. In the case of acute myocardial ischemia or myocardial infarction, atropine should be taken with caution since the increased heart rate may aggravate the ischemia or increase the size of the infarct.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 8
Correct
-
Which of the following clinical features is most suggestive of a lesion of the occipital lobe:
Your Answer: Homonymous hemianopia
Explanation:Homonymous hemianopia is a visual field defect involving either the two right or the two left halves of the visual fields of both eyes. It is caused by lesions of the retrochiasmal visual pathways, ie, lesions of the optic tract, the lateral geniculate nucleus, the optic radiations, and the cerebral visual (occipital) cortex
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 9
Incorrect
-
You've been asked to visit a 20-year-old patient who has been complaining of stomach pain, diarrhoea, and bloating. The GP recently saw the patient and is now looking into numerous possible reasons for stomach hypermotility.
Which of the following factors contributes to increased stomach motility?Your Answer: Calcitonin
Correct Answer: Gastrin
Explanation:Gastrin is a peptide hormone that aids in gastric motility by stimulating the generation of gastric acid by the parietal cells of the stomach. G-cells in the stomach’s pyloric antrum, the duodenum, and the pancreas release it.
The following stimuli cause the release of gastrin:
Stimulation of the vagus nerve
Hypercalcaemia
stomach bloating
Proteins that have been partially digested, particularly amino acids.
The presence of acid and somatostatin inhibits the release of gastrin.
Gastrin’s main actions are as follows:
Gastric parietal cells are stimulated to release hydrochloric acid.
ECL cells are stimulated to produce histamine.
Gastric parietal cell maturation and fundal growth stimulation
Causes the secretion of pepsinogen by the gastric chief cells.
Improves antral muscle mobility
stimulates gastric contractions
Increases gastric emptying rate and stimulates pancreatic secretion
Gallbladder emptying is induced. -
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
-
-
Question 10
Correct
-
The correct statement about the glomerular filtration barrier is which of the following?
Your Answer: The basement membrane is negatively charged, restricting filtration of negatively charged molecules.
Explanation:The main factor in determining whether a substance is filtered or not is molecular weight. Molecules < 7 kDa in molecular weight e.g. glucose, amino acids, urea, ions are filtered freely, but larger molecules are increasingly restricted up to 70 kDa, and there is very little filtration for anything above this.
There is further restriction of negatively charged molecules because they are repelled by negative charges, particularly in the basement membrane. Albumin, which has a molecular weight of 69 kDa and is negatively charged, is filtered but only in very small amounts. All of the filtered albumin is reabsorbed in the proximal tubule. Small molecules such as ions, glucose, amino acids and urea pass the filter without hindrance. Other than the ultrafiltrate being essentially protein free, it has an otherwise identical composition of plasma. Bowman’s capsule consists of:
– an epithelial lining which consists of a single layer of cells called podocytes
– endothelium which is perforated by pores or fenestrations – this allows plasma components with a molecular weight of < 70 kDa to pass freely. -
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 11
Incorrect
-
Regarding macrolide antibiotics, which of the following statements is CORRECT:
Your Answer: Macrolides interfere with bacterial DNA synthesis.
Correct Answer: Macrolides are first line for treatment of whooping cough.
Explanation:A macrolide antibiotic is recommended first line for whooping cough (if onset of cough is within the previous 21 days)
Prescribe clarithromycin for infants less than 1 month of age.
Prescribe azithromycin or clarithromycin for children aged 1 month or older, and non-pregnant adults.
Prescribe erythromycin for pregnant women.
Macrolides interfere with bacterial protein synthesis and are mainly active against Gram-positive organisms. They have a similar antibacterial spectrum to penicillin and are thus a useful alternative in penicillin-allergic patients. Erythromycin is commonly associated with gastrointestinal upset. -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 12
Incorrect
-
A 1-year-old male is brought to the paediatrician by his mother due to swelling of the right knee after a minor fall. On examination, the right knee is swollen, fluctuant and tender. Ultrasound-guided aspiration reveals a massive hemarthrosis. Family history shows that his older brother also has a bleeding disorder.
Which one of the following conditions does the patient most likely have?Your Answer: Von Willebrand disease
Correct Answer: Haemophilia A
Explanation:A diagnosis of Haemophilia is supported in this patient by the family history and the presence of hemarthrosis-both characteristics of Haemophilia. Haemophilia A is caused by Factor VIII deficiency, leading to impaired coagulation. This disease typically presents after six months when the child starts crawling.
Von Willebrand disease presents with nosebleeds and hematomas. Idiopathic thrombocytopenic purpura presents with bruises that resemble a rash.
Glucose-6-phosphate dehydrogenase (G6PD) deficiency presents with haemolytic anaemia induced by specific drugs or foods.
Factor V Leiden mutation causes blood clotting rather than bleeding.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 13
Incorrect
-
A 38-year-old woman is investigated for Addison's disease. She had low blood pressure, weakness, weight loss, and skin discoloration. An adrenocorticotropic hormone (ACTH) stimulation test is scheduled as part of her treatment.
Which of the following statements about ACTH is correct?Your Answer: It is secreted by the posterior pituitary
Correct Answer: It is released in response to the release of CRH
Explanation:The anterior pituitary gland produces and secretes a peptide hormone called adrenocorticotropic hormone (ACTH) (adenohypophysis). It is secreted in response to the hypothalamus’s secretion of the hormone corticotropin-releasing hormone (CRH).
ACTH promotes cortisol secretion via binding to cell surface ACTH receptors in the zona fasciculata of the adrenal cortex.
ACTH also promotes the production of beta-endorphin, which is a precursor to melanocyte-releasing hormone (MRH).
-
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 14
Correct
-
A 68-year-old man with multiple myeloma presents with complaints of abdominal pain and malaise. A series of blood tests is done and his calcium level is 2.96 mmol/l.
What effect will this blood test result have on gastric secretions?
Your Answer: Stimulate the release of gastrin
Explanation:Hypercalcaemia stimulates the release of gastrin from the G-cells in the pyloric antrum of the stomach, the duodenum and the pancreas.
Gastrin is also released in response to:
Stomach distension
Vagal stimulation
The presence of amino acids.Gastrin release is inhibited by the presence of acid and somatostatin.
-
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
-
-
Question 15
Correct
-
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: 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.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 16
Incorrect
-
In the small intestine, there is a deep gap between each villus that leads to the crypt of Lieberkühn, a tubular intestinal gland.
What is the primary function of these glands?
Your Answer: Secretion of cholecystokinin
Correct Answer: Production of an alkaline intestinal juice
Explanation:In the small intestine, there is a deep gap between each villus that leads to the crypt of Lieberkühn, a tubular intestinal gland. These glands create an alkaline intestinal juice that is a mixture of water and mucus with a pH of 7.4-7.8. Intestinal juice is released in a volume of 1-2 litres per day in response to distention of the small intestine or the irritating effects of chyme on the intestinal mucosa.
-
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
-
-
Question 17
Correct
-
A patient presents complaining of visual loss. On examination you note a contralateral homonymous hemianopia. Where is the most likely site of the lesion:
Your Answer: Optic tract
Explanation:At the optic chiasm, fibres from the medial (nasal) half of each retina crossover, forming the right and left optic tracts.
The left optic tract contains fibres from the left lateral (temporal) retina and the right medial retina.
The right optic tract contains fibres from the right lateral retina and the left medial retina.
Each optic tract travels to its corresponding cerebral hemisphere to reach its lateral geniculate nucleus (LGN) located in the thalamus where the fibres synapse.
A lesion of the optic tract will cause a contralateral homonymous hemianopia. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 18
Incorrect
-
Gastrin is secreted by which of the following cell types in the stomach:
Your Answer: Chief cells
Correct Answer: G-cells
Explanation:Gastrin is secreted by antral G-cells and acts on cholecystokinin B (CCKB) receptors.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 19
Correct
-
The most important Complement protein for antigen opsonization is:
Your Answer: C3b
Explanation:Phagocytosis is largely responsible for depletion of cells coated with antibodies. Cells opsonized by IgG antibodies are recognized by phagocyte Fc receptors, which are specific for the Fc portions of some IgG subclasses. In addition, when IgM or IgG antibodies are deposited on the surfaces of cells, they may activate the complement system by the classical pathway. Complement activation generates by-products, mainly C3b and C4b, which are deposited on the surfaces of the cells and recognized by phagocytes that express receptors for these proteins. The net result is phagocytosis of the opsonized cells and their destruction.
-
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 20
Incorrect
-
Question 21
Incorrect
-
In a ward round, you come across a patient's treatment chart prescribed an antibiotic to fight his infection. This antibiotic disrupts cell membrane function.
Which of the following antimicrobial drugs is prescribed to this patient?Your Answer: Flucloxacillin
Correct Answer: Nystatin
Explanation:Nystatin binds ergosterol (unique to the fungi cell membrane) and forms membrane pores that allow K+ leakage, acidification, and subsequent death of the fungus.
Vancomycin inhibits cell wall peptidoglycan formation by binding the D-Ala-D-Ala portion of cell wall precursors.
Flucloxacillin inhibits the synthesis of bacterial cell walls. It inhibits cross-linkage between the linear peptidoglycan polymer chains that make up a major component of the cell wall of Gram-positive bacteria.
Trimethoprim inhibits bacterial dihydrofolate reductase.
Isoniazid decreases the synthesis of mycolic acids in mycobacteria.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 22
Correct
-
An 8-year-old boy was brought to the emergency room with complaints of a rash and fever that have been present for the past 3 days. Upon history taking and observation, it was noted that the rash started behind the ears and then spread to the face and body. The presence of coryzal symptoms, dry cough, and conjunctivitis was also observed.
What is most likely the diagnosis of the case presented above?Your Answer: Measles
Explanation:The measles virus is an enveloped virus classified in the genus
Morbillivirus.
Measles is highly contagious and spreads by aerosol. Initial replication takes place in the mucosal cells of the respiratory tract; measles virus then replicates in the local lymph nodes and spreads systemically. The virus circulates in the T and B cells and monocytes, until eventually the lungs, gut, bile duct, bladder, skin, and lymphatic organs are involved. After an incubation period of 7 to 10 days, there is an abrupt onset, with symptoms of sneezing, runny nose and cough, red eyes, and rapidly rising fever. About 2 to 3 days later, a maculopapular rash appears on the head and trunk. Koplik spots, lesions on the oral mucosa consisting of irregular red spots, with a bluish white speck in the centre, generally appear 2 to 3 days before the rash and are diagnostic.Measles is easily diagnosed clinically, so few requests for laboratory identification are made. The virus is fragile and must be handled carefully. The specimens of choice are from the nasopharynx and urine, but the virus can only be recovered from these sources in the early stages of infection. The virus grows on PMK cells, causing the formation of distinctive spindle-shaped or multinucleated cells.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 23
Correct
-
Which of the following is NOT a typical clinical feature of diabetic ketoacidosis:
Your 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
-
-
Question 24
Incorrect
-
Regarding local anaesthetics, which of the following statements is INCORRECT:
Your Answer: Bupivacaine takes up to 30 minutes for a full effect.
Correct Answer: Adrenaline should be used in digital nerve blocks to create a bloodless field.
Explanation:It is not advisable to give adrenaline/epinephrine with a local anaesthetic injection in digits or appendages because of the risk of ischaemic necrosis.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 25
Correct
-
A 58-year-old man with a long history of depression presents with a deliberate overdose of verapamil tablets, which he is prescribed for a heart condition.
What is verapamil's mechanism of action?Your Answer: L-type calcium channel blockade
Explanation:Overdosing on calcium-channel blockers should always be taken seriously and regarded as potentially fatal. Verapamil and diltiazem are the two most lethal calcium channel blockers in overdose. These work by binding the alpha-1 subunit of L-type calcium channels, preventing calcium from entering the cell. In cardiac myocytes, vascular smooth muscle cells, and islet beta-cells, these channels play an important role.
The standard ABC approach should be used to resuscitate all patients as needed. If life-threatening toxicity is expected, intubation and ventilation should be considered early on. If hypotension and shock are developing, early invasive blood pressure monitoring is recommended.
The primary goal of specific treatments is to support the cardiovascular system. These are some of them:
1. Fluid resuscitation: Give up to 20 mL of crystalloid per kilogramme of body weight.
2. Calcium supplementation
This can be a good way to raise blood pressure and heart rate temporarily.
via central venous access: 10% calcium gluconate 60 mL IV (0.6-1.0 mL/kg in children) or 10% calcium chloride 20 mL IV (0.2 mL/kg in children)
Boluses can be given up to three times in a row.
To keep serum calcium >2.0 mEq/L, consider a calcium infusion.3. Atropine: 0.6 mg every 2 minutes up to 1.8 mg is an option, but it is often ineffective.
4. HIET (high-dose insulin-euglycemic therapy):
The role of HIET in the step-by-step management of cardiovascular toxicity has changed.5. Vasoactive infusions:
This was once thought to be a last-ditch measure, but it is now widely recommended that it be used sooner rather than later.
Insulin with a short half-life 50 mL of 50 percent glucose IV bolus plus 1 U/kg bolus (unless marked hyperglycaemia present)
Short-acting insulin/dextrose infusions should be continued.
Glucose should be checked every 20 minutes for the first hour, then hourly after that.
Regularly check potassium levels and replace if they fall below 2.5 mmol/L.
Titrate catecholamines to effect (inotropy and chronotropy); options include dopamine, adrenaline, and/or noradrenaline infusions.6. Sodium bicarbonate: Use 50-100 mEq sodium bicarbonate (0.5-1.0 mEq/kg in children) in cases where a severe metabolic acidosis develops.
7. Cardiac pacing: It can be difficult to achieve electrical capture, and it may not improve overall perfusion.
Bypass AV blockade with ventricular pacing, which is usually done at a rate of less than 60 beats per minute.8. Intralipid transport
Calcium channel blockers are lipid-soluble agents, so they should be used in refractory cases. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 26
Incorrect
-
A 24 year old male sustained an insect bite and presents with a red hot arm and acute cellulitis has been diagnosed. The predominant white cells in this type of acute inflammation are:
Your Answer: Macrophages
Correct Answer: Neutrophils
Explanation:Neutrophil polymorphs are the predominant type of white cells in an acute reaction. They pass between endothelial cell junctions to invade damaged tissue so that the effects of injury can be combated. Extravasation occurs with the movement of leukocytes out of the vessel lumen, and is achieved in five phases which are margination, ‘rolling’, adhesion, transmigration and chemotaxis.
-
This question is part of the following fields:
- Inflammatory Responses
- Pathology
-
-
Question 27
Incorrect
-
Which of the following statements is considered correct regarding Hepatitis B vaccination?
Your Answer: The vaccine is prepared from the viral core antigen
Correct Answer: The vaccine should be stored between 2 and 8 degrees Centigrade
Explanation:Hepatitis B vaccine should be stored at 35°-46° F (2°-8° C) and should not be frozen.
There is no association between hepatitis B vaccination and Guillain-Barre syndrome. Infection with the bacterium Campylobacter jejuni is one of the most common risk factors for GBS. People can also develop GBS after having the flu or other infections (such as cytomegalovirus and Epstein Barr virus).
Hepatitis B vaccine is prepared from initial concentration of surface antigen.
To ensure adequate immunity, anti-HBs (HBsAb) titres may be checked 4-8 weeks following the last shot of the hepatitis B vaccine series.
-
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
-
Question 28
Correct
-
A 27-year-old man has been diagnosed with testicular cancer and has spread to the regional lymph nodes.
The lymph from the testes will drain to which of the following nodes?Your Answer: Para-aortic lymph nodes
Explanation:Testes are retroperitoneal organs and its lymphatic drainage is to the lumbar and para-aortic nodes along the lumbar vertebrae.
The scrotum is the one which drains into the nearby superficial inguinal nodes.
The glans penis and clitoris drains into the deep inguinal lymph nodes.
-
This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
-
-
Question 29
Correct
-
A 45-year old man presented to the emergency room with complains of chest pain and breathlessness. Upon history taking and examination, it was discovered that he had a right-sided spontaneous pneumothorax and had a failed attempt at pleural aspiration. The pneumothorax is still considerable in size, but he remains breathless. A Seldinger chest drain was inserted but it started to drain frank blood shortly after.
Which of the following complications is most likely to have occurred?Your Answer: Intercostal artery laceration
Explanation:Injury to the intercostal artery (ICA) is an infrequent but potentially life-threatening complication of all pleural interventions.
Traditional anatomy teaching describes the ICA as lying in the intercostal groove, protected by the flange of the rib. This is the rationale behind the recommendation to insert needles just above the superior border of the rib. Current recommendations for chest drain insertion suggest that drains should be inserted in the ‘safe triangle’ in order to avoid the heart and the mediastinum and be above the level of the diaphragm.
The safe triangle is formed anteriorly by the lateral border of the pectoralis major, laterally by the lateral border of the latissimus dorsi, inferiorly by the line of the fifth intercostal space and superiorly by the base of the axilla. Imaging guidance also aids in the safety of the procedure.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 30
Correct
-
A 25-year-old patient requires procedural sedation for reduction of an open fracture of his tibia and fibula. You plan on using ketamine as the sedative agent.
Ketamine works as a result of action on what type of receptor? Select ONE answer only.Your Answer: N-methyl-D-aspartate (NMDA)
Explanation:Ketamine is the only anaesthetic agent available that has analgesic, hypnotic, and amnesic properties. When used correctly it is a very useful and versatile drug.
Ketamine acts by non-competitive antagonism of the NMDA receptor Ca2+ channel pore and also inhibits NMDA receptor activity by interaction with the phencyclidine binding site.
Ketamine can be used intravenously and intramuscularly. The intramuscular dose is 10 mg/kg, and when used by this route, it acts within 2-8 minutes and has a duration of action of 10-20 minutes. The intravenous dose is 1.5-2 mg/kg administered over a period of 60 seconds. When used intravenously, it acts within 30 seconds and has a duration of action of 5-10 minutes. Ketamine is also effective when administered orally, rectally, and nasally.
Ketamine causes tachycardia, an increase in blood pressure, central venous pressure, and cardiac output, secondary to an increase in sympathetic tone. Baroreceptor function is well maintained, and arrhythmias are uncommon.
The main disadvantage to the use of ketamine is the high incidence of hallucinations, nightmares, and other transient psychotic effects. These can be reduced by the co-administration of a benzodiazepine, such as diazepam or midazolam.
The main side effects of ketamine are:
Nausea and vomiting
Hypertension
Nystagmus
Diplopia
Rash -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 31
Incorrect
-
Which of the following statements is incorrect regarding the Na+/K+ATPase pump?
Your Answer: The Na + /K + ATPase pump facilitates movement by primary active transport.
Correct Answer: The Na + /K + ATPase pump moves 3 Na + ions into the cell for every 2 K + ions out.
Explanation:In order for primary active transport to pump ions against their electrochemical gradient, chemical energy is used in the form of ATP. The Na+/K+-ATPase antiporter pump uses metabolic energy to move 3 Na+ions out of the cell for every 2 K+ions in, against their respective electrochemical gradients. As a result, the cell the maintains a high intracellular concentration of K+ions and a low concentration of Na+ions.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 32
Incorrect
-
All of the following statements are incorrect about insulin except:
Your Answer: Insulin is secreted from pancreatic alpha cells.
Correct Answer: Proinsulin is cleaved into insulin and C peptide.
Explanation:Proinsulin is synthesised as a single-chain peptide. A connecting peptide (C peptide) within storage granules is removed by proteases to yield insulin.
Insulin:
1. is a polypeptide hormone consisting of two short chains (A and B) linked by disulphide bonds.
2. is produced by beta cells, located centrally within the islets of Langerhans, in the endocrine tissues of the pancreas.
3. release is stimulated initially during eating by the parasympathetic nervous system and gut hormones such as secretin. However, most output is driven by the rise in plasma glucose concentration that occurs after a meal.
4. effects are mediated by the receptor tyrosine kinase. -
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 33
Incorrect
-
Damage to this nerve affects the flexor digitorum longus.
Your Answer: Sciatic nerve
Correct Answer: Tibial nerve
Explanation:Like all muscles in the deep posterior compartment of the leg, flexor digitorum longus muscle is innervated by branches of the tibial nerve (root value L5, S1 and S2) which is a branch of sciatic nerve.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 34
Incorrect
-
A 70-year-old patient is diagnosed with Cushing's disease. She has a history of weight gain, hypertension, and easy bruising.
In this patient, which of the following is the MOST LIKELY UNDERLYING CAUSE?Your Answer: Adrenal adenoma
Correct Answer: Pituitary adenoma
Explanation:Cushing’s syndrome is a collection of symptoms and signs caused by prolonged exposure to elevated levels of either endogenous or exogenous glucocorticoids.
The most common cause of Cushing’s syndrome is the iatrogenic administration of corticosteroids. The second most common cause of Cushing’s syndrome is Cushing’s disease.
Cushing’s disease should be distinguished from Cushing’s syndrome and refers to one specific cause of the syndrome, an adenoma of the pituitary gland that secretes large amounts of ACTH and, in turn, elevates cortisol levels. This patient has a diagnosis of Cushing’s disease, and this is, therefore, the underlying cause in this case.
The endogenous causes of Cushing’s syndrome include:
Pituitary adenoma (Cushing’s disease)
Ectopic corticotropin syndrome, e.g. small cell carcinoma of the lung
Adrenal hyperplasia
Adrenal adenoma
Adrenal carcinoma -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 35
Incorrect
-
A patient sustains an injury to the proximal median nerve after falling through a glass door. Which of the following muscles would you not expect to be affected:
Your Answer: Flexor pollicis longus
Correct Answer: Flexor carpi ulnaris
Explanation:All of the muscles in the anterior forearm are innervated by the median nerve, except for the flexor carpi ulnaris and the medial half of the flexor digitorum profundus which are innervated by the ulnar nerve.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 36
Correct
-
A 15-year-old girl took 20 tablets of paracetamol almost 4 hours ago after her mother for refused to provide her permission for her to go on a girl's trip. The girl is healthy and has no known comorbidities or drug history. Which one of the following is TRUE regarding paracetamol?
Your Answer: It is excreted renally
Explanation:Acetaminophen is an acetanilide derivative and is a widely used non-prescription analgesic and antipyretic medication for mild-to-moderate pain and fever.
The route of elimination: Paracetamol is metabolised extensively in the liver and excreted in the urine mainly as inactive glucuronide and sulfate conjugates, <5% is excreted as free (unconjugated) acetaminophen, and >90% of the dose administered is excreted within 24 hours.
It is thought to work by selectively inhibiting COX-1 receptors in the brain and spinal cord: It is categorized by the FDA as an NSAID as it is believed to selectively inhibit cyclo-oxygenase 3 (COX-3) receptors in the brain and spinal cord.
COX-3 is a unique variant of the more known COX-1 and COX-2. It is responsible for the production of prostaglandins in central areas, which sensitizes free nerve endings to the chemical mediators of pain. Therefore, by selectively inhibiting COX-3, paracetamol effectively reduces pain sensation by increasing the pain threshold.
Toxicity is primarily due to glutathione production: Acetaminophen metabolism by the CYP2E1 pathway releases a toxic metabolite known as N-acetyl-p-benzoquinoneimine (NAPQI). NAPQI primarily contributes to the toxic effects of acetaminophen. NAPQI is an intermediate metabolite that is further metabolized by fast conjugation with glutathione. The conjugated metabolite is then excreted in the urine as mercapturic acid. High doses of acetaminophen (overdoses) can lead to hepatic necrosis due to depleting glutathione and high binding levels of reactive metabolite (NAPQI) to important parts of liver cells.
Acetaminophen can be administered orally, rectally, or intravenously. It is predominantly metabolized in the liver, and the elimination half-life is 1-3 hours after a therapeutic dose. But maybe greater than 12 hours after an overdose.
It is primarily metabolized via the cytochrome p450 enzyme system: It is predominantly metabolized in the liver by three main metabolic pathways:
1. Glucuronidation (45-55%)
2. Sulphate conjugation (30-35%)
3. N-hydroxylation via the hepatic cytochrome p450 enzyme system (10-15%) -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 37
Correct
-
Which law describes the rate of diffusion in a solution?
Your Answer: Fick’s law
Explanation:Fick’s law describes the rate of diffusion in a solution. Fick’s law states that:
Jx = -D A (ΔC / Δx)
Where:
Jx = The amount of substance transferred per unit time
D = Diffusion coefficient of that particular substance
A = Surface area over which diffusion occurs
ΔC = Concentration difference across the membrane
Δx = Distance over which diffusion occurs
The negative sign reflects movement down the concentration gradient -
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
-
-
Question 38
Incorrect
-
A 68-year-old man with BPH presents to the emergency department in significant pain secondary to urinary retention. What is the location of the neuronal cell bodies that are responsible for urinary bladder discomfort sensation?
Your Answer: Dorsal root ganglia of spinal cord levels T10 - T12
Correct Answer: Dorsal root ganglia of spinal cord levels S2, S3 and S4
Explanation:The activation of stretch receptors with visceral afferents relayed through the pelvic nerve plexus and into the pelvic splanchnic nerves causes bladder pain. The sensory fibres of spinal nerves S2 – S4 enter the dorsal root ganglia.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 39
Correct
-
A 67-year-old female is admitted under your care with the complaint of shortness of breath and massive pedal oedema. There are fine crepitations up to the mid zones on both lung fields on chest auscultation. When questioned about her medication, she doesn't remember everything she takes but knows that there is a tablet to get rid of excess water.
Out of the following medications, which one increases the osmolality of the filtrate in the glomerulus and the tubule, creating an osmotic effect?Your Answer: Mannitol
Explanation:Mannitol is an osmotic diuretic that stops the absorption of water throughout the tubule, thus increasing the osmolality of both glomerular and tubular fluid. It is used to:
1. decrease intraocular pressure in glaucoma
2. decrease intracerebral pressure
3. oliguria.Furosemide is a loop diuretic that inhibits the Na/K/2Cl transported in the ascending limb of the Loop of Henle.
Bendroflumethiazide is a thiazide diuretic which inhibits the Na/Cl transporter.
Spironolactone is a potassium-sparing diuretic that acts as an aldosterone receptor antagonist.
Acetazolamide is a carbonic anhydrase inhibitor.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 40
Incorrect
-
A 64-year-old woman with a history of chronic breathlessness is referred for lung function testing.
Which of the following statements regarding lung function testing is FALSE? Select ONE answer only.Your Answer: COPD can only be diagnosed on spirometry if the FEV 1 is <80% and FEV 1 /FVC ratio is <0.7
Correct Answer: In restrictive lung disease, the FVC is increased
Explanation:In restrictive lung disorders there is a reduction in the forced vital capacity (FVC) and the forced expiratory volume in one second (FEV1). The decline in the FVC is greater than that of the FEV1, resulting in preservation of the FEV1/FVC ratio (>0.7%).
In obstructive lung disease, FEV1is reduced to <80% of normal and FVC is usually reduced but to a lesser extent than FEV1. The FEV1/FVC ratio is reduced to <0.7.
According to the latestNICE guidelines(link is external), airflow obstruction is defined as follows:
Mild airflow obstruction = an FEV1 of >80% in the presence of symptoms
Moderate airflow obstruction = FEV1 of 50-79%
Severe airflow obstruction = FEV1 of 30-49%
Very severe airflow obstruction = FEV1<30%.
Spirometry is a poor predictor of durability and quality of life in COPD but can be used as part of the assessment of severity.
COPD can only be diagnosed on spirometry if the FEV1 is <80% and FEV1/FVC ratio is < 0.7. -
This question is part of the following fields:
- Physiology
- Respiratory Physiology
-
-
Question 41
Incorrect
-
The following statements about cross-sectional studies are true EXCEPT?
Your Answer: They provide a ‘snapshot’ of the frequency and characteristics of a disease in a population at a particular point
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.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 42
Incorrect
-
Regarding Clostridium perfringens, which of the following statements is CORRECT:
Your Answer: It has endotoxin-mediated effects in tissue causing severe tissue damage.
Correct 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.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 43
Incorrect
-
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: Increase growth hormone levels
Correct 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.
-
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
-
-
Question 44
Incorrect
-
Which of the following statements is correct with regards to heparin-induced thrombocytopaenia (HIT)?
Your Answer: HIT only occurs with unfractionated heparin.
Correct Answer: HIT typically develops 5-10 days after starting heparin.
Explanation:Heparin-induced thrombocytopenia (HIT) is a prothrombotic disorder caused by antibodies that recognize complexes of platelet factor 4 (PF4) and heparin. HIT is frequently considered in the differential diagnosis of thrombocytopenia occurring in patients on heparin therapy. HIT is a challenging diagnosis because of routine heparin use in hospitalized patients, the common occurrence of thrombocytopenia. The process of heparin dependent IgG antibodies binding to heparin/platelet factor 4 complexes activates platelets and produces a hypercoagulable state. This syndrome typically develops 5-10 days (range 4-15 days) after heparin is commenced. It can occur with unfractionated heparin, low molecular weight heparin, or, rarely, fondaparinux. The diagnosis of HIT requires the combination of a compatible clinical picture and laboratory confirmation of the presence of heparin dependent platelet activating HIT antibodies. Discontinuation of heparin alone or initiation of a vitamin K antagonist alone like warfarin, is not sufficient to stop the development of thrombosis in patients with acute HIT. If there is moderate clinical suspicion for HIT, all sources of heparin must be discontinued and there must be consideration of anticoagulant treatment with a non-heparin drug.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 45
Correct
-
You've been summoned to a young man in the resus area who is experiencing an SVT. You decide to use adenosine after trying several vagal manoeuvres without success.
Which of the following is the correct adenosine mechanism of action?Your Answer: Opens K + channels in the heart
Explanation:The purine nucleoside adenosine is used to diagnose and treat paroxysmal supraventricular tachycardia. Adenosine works by stimulating A1-adenosine receptors and opening potassium channels that are sensitive to acetylcholine. This causes the atrioventricular (AV) node’s cell membrane to become hyperpolarized, slowing conduction by inhibiting calcium channels.
Patients who have had a heart transplant are extremely sensitive to the effects of adenosine and should start with a lower dose of 3 mg, then 6 mg, and finally 12 mg.Dipyridamole potentiates the effects of adenosine, so it should be used with caution in patients who are taking it.
The use of adenosine is contraindicated in the following situations:
Asthma
COPD (chronic obstructive pulmonary disease)
Decompensated heart failure
Long QT syndrome
AV block in the second or third degree
Sinusitis is a condition in which the sinuses become (unless pacemaker fitted)
Hypotension that is severe -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 46
Incorrect
-
A patient presents with an adducted eye at rest which cannot abduct past the midline, which of the following cranial nerves is most likely to be affected:
Your Answer: Oculomotor nerve
Correct Answer: Abducens nerve
Explanation:Abducens nerve palsies result in a convergent squint at rest (eye turned inwards) with inability to abduct the eye because of unopposed action of the rectus medialis. The patient complains of horizontal diplopia when looking towards the affected side. With complete paralysis, the eye cannot abduct past the midline.
-
This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
-
-
Question 47
Correct
-
A patient presents with pain in the wrist and a tingling in the hand. On examination Tinel's test is positive and you diagnose carpal tunnel syndrome. Regarding the carpal tunnel, which of the following statements is INCORRECT:
Your Answer: The tendons of the flexor digitorum profundus, flexor digitorum superficialis and flexor pollicis longus lie within a single synovial sheath.
Explanation:Free movement of the tendons in the carpal tunnel is facilitated by synovial sheaths, which surround the tendons. All of the tendons of the flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) are contained within a single synovial sheath with a separate sheath enclosing the tendon of the flexor pollicis longus (FPL).
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 48
Incorrect
-
Regarding iron handling, which of the following statements is CORRECT:
Your Answer: Most iron in the body is stored in the liver.
Correct Answer: Iron is taken across the enterocyte apical membrane by the divalent metal transporter (DMT1).
Explanation:Dietary iron may be in the form of haem or non-haem iron. Haem iron is degraded after absorption through the cell surface to release Fe2+. Most non-haem iron is in the form Fe3+, which is reduced at the luminal surface to the more soluble Fe2+, facilitated by hydrochloric acid in gastric secretions (and enhanced by ascorbic acid). Fe2+is taken across the enterocyte apical membrane by the divalent metal transporter (DMT1). In the enterocyte, Fe2+is then either stored in enterocyte epithelial cells as ferritin, or released into portal plasma via the molecule ferroportin at the basolateral membrane.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 49
Correct
-
How does aspirin mediate its antiplatelet effect:
Your Answer: It irreversibly inhibits cyclo-oxygenase
Explanation:Aspirin irreversibly inhibits cyclooxygenase and blocks the platelet production of thromboxane A2 (TXA2), thus inhibiting platelet aggregation.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 50
Incorrect
-
Regarding a cohort study, which of the following statements is INCORRECT:
Your Answer: It is observational.
Correct Answer: It is useful for rare diseases.
Explanation:A cohort study is a longitudinal, prospective, observational study that follows a defined group (cohort) matched to unexposed controls for a set period of time and investigates the effect of exposure to a risk factor on a particular future outcome. The usual outcome measure is the relative risk (risk ratio). A large sample size is required for a rare outcome of interest so it is not useful for rare diseases.
-
This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
-
-
Question 51
Incorrect
-
Regarding NSAIDs, which of the following statements is CORRECT:
Your Answer: Mefenamic acid has very potent anti-inflammatory properties.
Correct Answer: Diclofenac is contraindicated in people with ischaemic heart disease.
Explanation:Due to their increased risk of cardiovascular adverse events, coxibs and diclofenac are contraindicated in people with ischaemic heart disease, cerebrovascular disease, peripheral arterial disease and mild, moderate, or severe heart failure. Other NSAIDs are only contraindicated in people with severe heart failure. Selective inhibition of COX-2 is associated with less gastrointestinal intolerance. In single doses NSAIDs have analgesic activity comparable to that of paracetamol, therefore given their side effect profile, paracetamol is preferred, particularly in the elderly. Pain relief starts soon after taking the first dose and a full analgesic effect should normally be obtained within a week, whereas an anti-inflammatory effect may not be achieved (or may not be clinically assessable) for up to 3 weeks. Mefenamic acid has only very mild anti-inflammatory properties.
-
This question is part of the following fields:
- Musculoskeletal
- Pharmacology
-
-
Question 52
Incorrect
-
CSF is reabsorbed from subarachnoid space via which of the following structures:
Your Answer: Choroid plexus
Correct Answer: Arachnoid granulations
Explanation:From the subarachnoid cisterns in the subarachnoid space, CSF is reabsorbed via arachnoid granulations which protrude into the dura mater, into the dural venous sinuses and from here back into the circulation.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 53
Incorrect
-
Infection with Campylobacter jejuni is one of the most common risk factors for which of the following conditions?
Your Answer: Haemolytic uraemic syndrome
Correct Answer: Guillain-Barre syndrome
Explanation:One of the most common risk factors for GBS is infection with Campylobacter jejuni, which causes diarrhoea.
Guillain-Barré syndrome (GBS) is a rare autoimmune disorder in which the body’s immune system attacks the nerves, resulting in muscle weakness and paralysis.
Infection with Streptococcus pyogenes can cause acute glomerulonephritis and rheumatic fever.
Haemolytic uraemic syndrome is commonly linked to E. coli infection.
Following measles infection, subacute sclerosing panencephalitis develops.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 54
Correct
-
Swelling of the lips, tongue, and face is observed in a 59-year-old African-American woman. In the emergency room, she is given intramuscular adrenaline, but her symptoms do not improve. Her GP recently started her on a new medication.
Which of the following drugs is most likely to have caused her symptoms?Your Answer: Ramipril
Explanation:Angiotensin-converting enzyme (ACE) inhibitors are the most common cause of drug-induced angioedema in the United Kingdom and the United States, owing to their widespread use.
Angioedema is caused by ACE inhibitors in 0.1 to 0.7 percent of patients, with data indicating a persistent and relatively constant risk year after year. People of African descent have a five-fold higher chance of contracting the disease.
Swelling of the lips, tongue, or face is the most common symptom, but another symptom is episodic abdominal pain due to intestinal angioedema. Itching and urticaria are noticeably absent.
The mechanism appears to be activated complement or other pro-inflammatory cytokines like prostaglandins and histamine, which cause rapid vasodilation and oedema.
Other medications that are less frequently linked to angioedema include:
Angiotensin-receptor blockers (ARBs)
Nonsteroidal anti-inflammatory drugs (NSAIDs)
Bupropion (e.g. Zyban and Wellbutrin)
Beta-lactam antibiotics
Statins
Proton pump inhibitorsThe majority of these reactions are minor and can be treated by stopping the drug and prescribing antihistamines.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 55
Correct
-
This anatomic part lies at the heart of the tooth.
Your Answer: The pulp cavity
Explanation:Within the central portion of the tooth lies the dental pulp. The pulp chamber provides mechanical support and functions as a barrier from external stimuli and the oral microbiome. The dental pulp is a unique tissue that is richly innervated and has an extensive microvascular network. Maintaining its vitality increases both the mechanical resistance of the tooth and the long-term survival. The junctional epithelium forms a band around the tooth at the base of the gingival sulcus, sealing off the periodontal tissues from the oral cavity.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 56
Incorrect
-
A 56-year-old female presents at the hospital with a diabetic foot ulcer that has become infected. She has a longstanding history of type 2 diabetes mellitus and diabetic polyneuropathy. She has trouble controlling her blood sugar levels, and recently, she was converted to a new insulin regimen that includes intermediate-acting insulin.
Out of the following, which one is the intermediate-acting insulin?Your Answer: Insulin aspart
Correct Answer: Isophane insulin
Explanation:Insulin is used mainly in type 1 diabetes, where the pancreas makes no insulin and can sometimes be prescribed in type 1 diabetes. There are different types of insulin categorized by their onset of action:
1. Intermediate-acting insulins (isophane insulin NPH):
– intermediate duration of action, designed to mimic the effect of endogenous basal insulin
– starts their action in 1 to 4 hours
– peaks in 4 to 8 hours
– dosing is usually twice a day and helps maintain blood sugar throughout the day
– Isophane insulin is a suspension of insulin with protamine2. Short-acting insulins (regular insulin)
– starts the action in 30 to 40 minutes
– peaks in 90 to 120 minutes
– duration of action is 6 to 8 hours
– taken before meals, and food is necessary within 30 minutes after its administration to avoid hypoglycaemia3. Long-acting insulins (glargine, detemir, degludec)
– start action in 1 to 2 hours
– plateau effect over 12 to 24 hours
– Dosing is usually during the night-time after meals. Their long duration of action helps in reducing the frequency of dosing throughout the day.4. Rapid-acting insulins (lispro, aspart, glulisine)
– start their action in 5 to 15 minutes
– peak in 30 minutes
– The duration of action is 3 to 5 hours
– generally used before meals and always used along with short-acting or long-acting insulins to control sugar levels throughout the day. -
This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
-
-
Question 57
Correct
-
A 55-year-old male diabetic patient presents to the Emergency Room complaining of severe chest pain. His medical record shows that he had coronary angioplasty one week ago, during which he was administered abciximab.
Which of the following haematological diseases has a similar mechanism of action to this drug?Your Answer: Glanzmann’s thrombasthenia
Explanation:Abciximab is glycoprotein IIb/IIIa receptor antagonist that decreases aggregation of platelets by prevent their cross-linking. In Glanzmann’s thrombasthenia there are low levels of these same receptors leading to decreased bridging of platelets as fibrinogen cannot attach. There is increased bleeding time both in this disease and when there is use of abciximab.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 58
Correct
-
Which of the following statements is true regarding a pleural aspiration?
Your Answer: The needle should be inserted just above the upper border of the chosen rib
Explanation:Pleural aspiration describes a procedure whereby pleural fluid or air may be aspirated via a system inserted temporarily into the pleural space. This may be for diagnostic purposes (usually removing 20–50 ml fluid) or therapeutic to relieve symptoms. In the literature it is varyingly called thoracocentesis, thoracentesis or pleural aspiration.
In determining the correct patient position and site of insertion, it is important for the operator to be aware of the normal anatomy of the thorax and the pathology of the patient. Patient position is dependent on the operator preference and the site of the pathology. In the case of a posterior lying locule, this may be specific to the image-guided spot where fluid is most likely to be obtained. In most circumstances, however, the site of insertion of the needle is either in the triangle of safety or the second intercostal space in the midclavicular line. The patient may therefore either sit upright leaning forward with arms elevated but resting on a table or bed, thereby exposing the axilla, or lying on a bed in a position. The needle is inserted in the space just above the chosen rib to avoid damaging the neurovascular bundle. It is common practice to insert the needle more posteriorly for a pleural aspiration, but it should be noted that the neurovascular bundle may not be covered by the lower flange of the rib in this position and a more lateral or anterior site of insertion is considered safer.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 59
Incorrect
-
Regarding the cardiac cycle, which of the following statements is INCORRECT:
Your Answer: During systole, contraction of the ventricles compresses the coronary arteries and suppresses blood flow.
Correct Answer: The second heart sound occurs in late diastole caused by closure of the atrioventricular valves.
Explanation:Diastole is usually twice the length of systole at rest, but decreases with increased heart rate. During systole, contraction of the ventricles compresses the coronary arteries and suppresses blood flow. This is particularly evident in the left ventricle, where during systole the ventricular pressure is the same as or greater than that in the arteries and as a result more than 85% of left ventricular perfusion occurs during diastole. This becomes a problem if the heart rate is increased as the diastolic interval is shorter and can result in ischaemia. The second heart sound, caused by closure of the semilunar valves, marks the end of systole.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 60
Incorrect
-
Regarding folate requirements, which of the following statements is CORRECT:
Your Answer: Absorption of folate is primarily from the terminal ileum.
Correct Answer: Dietary folate is found particularly in leafy green vegetables and liver.
Explanation:Megaloblastic anemia results from inhibition of DNA synthesis during red blood cell production. When DNA synthesis is impaired, the cell cycle cannot progress from the growth stage to the mitosis stage. This leads to continuing cell growth without division, which presents as macrocytosis, with an increase in mean corpuscular volume (MCV). The defect in red cell DNA synthesis is most often due to hypovitaminosis, specifically vitamin B12 deficiency or folate deficiency.
Folate is an essential vitamin found in most foods, especially liver, green vegetables and yeast. The normal daily diet contains 200 – 250 μg, of which about 50% is absorbed. Daily adult requirements are about 100 μg. Absorption of folate is principally from the duodenum and jejunum. Stores of folate are normally only adequate for 4 months and so features of deficiency may be apparent after this time. -
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 61
Incorrect
-
What is the recommended dosing regime for amiodarone in the treatment of a stable regular broad-complex tachycardia:
Your Answer: 150 mg IV bolus, followed by two further 300 mg IV boluses if no response
Correct Answer: 300 mg IV over 10 - 60 minutes, followed by an IV infusion of 900 mg over the next 24 hours
Explanation:A ventricular tachycardia (or broad-complex tachycardia of uncertain origin) should be treated with amiodarone 300 mg IV over 10 – 60 min, followed by an infusion of 900 mg over the next 24 hours.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 62
Incorrect
-
Which of the following virulence factors of E. coli is important for attachment to host epithelial cells in the pathogenesis of urinary tract infections:
Your Answer: Toxin A
Correct Answer: Pili
Explanation:Escherichia coli is the most common cause of urinary tract infection. Uropathic strains are characterised by pili with adhesion proteins that bind to specific receptors on the urinary tract epithelium. The motility of E. coli aids its ability to ascend the urethra into the bladder or ascend the ureter into the kidney.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 63
Incorrect
-
Which of the following statements accurately describes the extensor indicis muscle?
Your Answer: It receives its blood supply from the ulnar artery
Correct 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.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 64
Incorrect
-
A 68-year-old man has a very fast heartbeat' and is out of breath. He has had a heart transplant in the past. His electrocardiogram reveals supraventricular tachycardia.
Which of the following is the most appropriate adenosine dose for him to receive as a first dose?Your Answer: Adenosine 6 mg IV
Correct Answer: Adenosine 3 mg IV
Explanation:A rapid IV bolus of adenosine is given, followed by a saline flush. The standard adult dose is 6 mg, followed by 12 mg if necessary, and then another 12 mg bolus every 1-2 minutes until an effect is seen.
Patients who have had a heart transplant, on the other hand, are extremely sensitive to the effects of adenosine and should start with a lower dose of 3 mg, then 6 mg, and finally 12 mg.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 65
Correct
-
Typically, granulomatous inflammation is associated with one of the following infections:
Your 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
-
This question is part of the following fields:
- Inflammatory Responses
- Pathology
-
-
Question 66
Incorrect
-
An 80-year-old female complains of chest pain characteristic of angina. A dose of glyceryl trinitrate (GTN) is administered that resolves the chest pain rapidly.
Which ONE of the following is released on the initial metabolism of GTN?Your Answer: Nitric oxide
Correct Answer: Nitrite ions
Explanation:Angina pectoris is the most common symptom of ischemic heart disease and presents with chest pain relieved by rest and nitro-glycerine.
Nitrates are the first-line treatment to relieve chest pain caused by angina. The commonly used nitrates are:
1. Glyceryl trinitrate
2. Isosorbide dinitrateThe nitrate drugs are metabolized in the following steps:
1. Release Nitrite ions (NO2-), which are then converted to nitric oxide (NO) within cells.
2. NO activates guanylyl cyclase, which causes an increase in the intracellular concentration of cyclic guanosine-monophosphate (cGMP) in vascular smooth muscle cells.
3. Relaxation of vascular smooth muscle.Although nitrates are potent coronary vasodilators, their principal benefit in the management of angina results from a predominant mechanism of venous dilation:
– Bigger veins hold more blood
– Takes blood away from the left ventricle
– Lowers LVEDV (preload), LA pressure
– Less pulmonary oedema → improved dyspnoea -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 67
Incorrect
-
If a patient dislocated his right shoulder and has been referred to the orthopaedic outpatient department for a follow-up after a successful reduction, which of the following is the most important position for him to avoid holding his arm in until he is seen in the clinic?
Your Answer:
Correct Answer: Arm at 90 degrees to side with palm up
Explanation:The arm should be placed in a poly-sling that should be worn for about two weeks. A physiotherapist may give gentle movements for the arm to help in reducing stiffness and in relieving the pain. It is important that the patient must avoid positions that could cause re-dislocation.
The most important position to avoid is the arm being held out at 90 degrees to the side with the palm facing upwards, especially if a force is being applied. -
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 68
Incorrect
-
You examine a child who has been admitted to the paediatric emergency department with a flu-like illness. His parents tell you that he was born with an inborn defect of steroid metabolism and that he was treated for it with hormone replacement therapy.
Which of the following is classified as a steroid hormone?
Your Answer:
Correct Answer: Aldosterone
Explanation:Hormones can be classified into three categories depending on their chemical composition: amines, peptides (and proteins), and steroids. Amines are made up of single amino acids (for example, tyrosine), peptide hormones are made up of peptides (or proteins), and steroid hormones are made up of cholesterol.
The table below lists some prominent instances of each of these three hormone classes:1. Peptide hormone:
Adrenocorticotropic hormone (ACTH)
Prolactin
Vasopressin
Oxytocin
Glucagon
Insulin
Somatostatin
Cholecystokinin2. Amine hormone:
Adrenaline (epinephrine)
Noradrenaline (norepinephrine)
Dopamine3. Steroid hormone:
Mineralocorticoids (e.g. aldosterone)
Glucocorticoids (e.g. cortisol)
Progestogens
Androgens
Oestrogens -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 69
Incorrect
-
A 38-year-old man returns from an overseas business trip with a fever and a headache. Following investigations a diagnosis of Plasmodium falciparum malaria is made.
Which of the following statements regarding Plasmodium falciparum malaria is true? Select ONE answer only.Your Answer:
Correct Answer: There may be a continuous fever
Explanation:Plasmodium falciparum malaria is transmitted by female of the Anopheles genus of mosquito. The Aedes genus is responsible for transmitting diseases such as dengue fever and yellow fever.
Plasmodium falciparumis found globally but is mainly found in sub-Saharan Africa.
The incubation period of Plasmodium falciparum malaria is 7-14 days.
Sporozoites invade hepatocytes. Within the hepatocyte asexual reproduction occurs producing merozoites, which are released into the blood stream and invade the red blood cells of the host.
Artesunate is the drug treatment of choice for Plasmodium falciparum malaria. Quinine can still be used where artesunate is not available. Often combination therapy with drugs such as doxycycline or fansidar is also required.
The classic symptom of malaria is the malarial paroxysm, a cyclical occurrence of a cold phase, where the patient experiences intense chills, a hot stage, where the patient feels extremely hot and finally a sweating stage, where the fever declines and the patient sweats profusely. There may also, however, be a continuous fever. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 70
Incorrect
-
Oculomotor (CN III) palsy with sparing of the pupillary reflex is most likely caused by which of the following:
Your Answer:
Correct Answer: Diabetes mellitus
Explanation:Compressive causes of CN III palsy cause early pupillary dilatation because the parasympathetic fibres run peripherally in the nerve and are easily compressed. In diabetes mellitus the lesions are ischaemic rather than compressive and therefore typically affect the central fibres resulting in pupillary sparing.
-
This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
-
-
Question 71
Incorrect
-
A blood transfusion is given to a 52-year-old woman. She develops chills and rigours shortly after the transfusion begins.
The following are her observations: Temperature 40°C, HR 116 bpm, BP 80/48, SaO 2 97 percent on air.
Which of the following treatments is the most appropriate?Your Answer:
Correct Answer: Stop the transfusion and administer antibiotics
Explanation:Bacterial infections are common in the following situations:
Platelet transfusions are associated with a higher risk of bacterial infection (as platelets are stored at room temperature)
Immersion in a water bath thawed previously frozen components.
Components of red blood cells that have been stored for several weeks
Gram-positive and Gram-negative bacteria have both been linked to transfusion-transmitted bacterial infection, but Gram-negative bacteria are linked to a higher rate of morbidity and mortality.
Yersinia enterocolitica is the most common bacterial organism linked to transfusion-transmitted bacterial infection. This organism can multiply at low temperatures while also utilising iron as a nutrient. As a result, it’s well-suited to proliferating in blood banks.The following are some of the most common clinical signs and symptoms of a bacterial infection transmitted through a blood transfusion. These symptoms usually appear shortly after the transfusion begins:
Fever is very high.
Rigours and chills
Vomiting and nausea
Tachycardia
Hypotension
Collapse of the circulatory systemIf a bacterial infection from a transfusion is suspected, the transfusion should be stopped right away. Blood cultures and a Gram stain should be requested, as well as broad-spectrum antibiotics. In addition, the blood pack should be returned to the blood bank for an urgent culture and Gram-stain.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 72
Incorrect
-
Regarding fat digestion, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Chylomicrons consist of a cholesterol and triglyceride core with a phospholipid coat studded with apolipoproteins.
Explanation:Dietary fat is chiefly composed of triglycerides. In the duodenum fat is emulsified by bile acids, a process where larger lipid droplets are broken down into much smaller droplets providing a greater surface area for enzymatic digestion. Once inside the epithelial cell, lipid is taken into the smooth endoplasmic reticulum where much of it is re esterified. Dietary and synthesised lipids are then incorporated into chylomicrons in the Golgi body, which are exocytosed from the basolateral membrane to enter lacteals. Chylomicrons consist mainly of triglyceride with small amounts of cholesterol and cholesteryl esters in the centre with a phospholipid coat studded with apolipoproteins. Fat-soluble are absorbed into enterocytes from micelles by simple diffusion together with the products of fat digestion.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 73
Incorrect
-
Regarding linear relationships between two variables, what does a positive correlation coefficient indicate:
Your Answer:
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.
-
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 74
Incorrect
-
The interquartile range (IQ) is often displayed using which of the following:
Your Answer:
Correct Answer: Box and whisker plot
Explanation:A boxplot is a vertical or horizontal rectangle used to display the interquartile range, with the ends of the rectangle corresponding to the upper and lower quartiles of the data values. The box contains 50% of the data values. A line drawn through the rectangle corresponds to the median value. Whiskers, starting at the ends of the rectangle usually indicate the minimum and maximum values, therefore the entire box and whisker plot represents the range. Any outliers can be plotted independent of the box and whisker plot.
-
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 75
Incorrect
-
Regarding the tongue, which of the following statements is CORRECT:
Your Answer:
Correct Answer: The lymphatic supply of the tongue drains to the jugulo-omohyoid node of the deep cervical chain.
Explanation:All lymphatics from the tongue ultimately drain into the deep cervical chain of nodes along the internal jugular vein, particularly the jugulo-omohyoid lymph node.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 76
Incorrect
-
Question 77
Incorrect
-
A dermatological examination of a patient presenting with a lump shows a visible collection of fluid measuring 0.3 cm in diameter.
Which one of these best describes the lump you have found on examination?Your Answer:
Correct Answer: Vesicle
Explanation:A vesicle is a visible collection of fluid measuring less than 0.5 cm in diameter.
A furuncle, or boil, is a pyogenic infection of the hair follicle commonly caused by infection with Staphylococcus aureus.
A carbuncle is a collection of individual boils clustered together.
A bulla is a visible collection of clear fluid measuring greater than 0.5 cm in diameter.
A pustule is a small visible skin elevation containing an accumulation of pus.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 78
Incorrect
-
Osteoclasts are a type of bone cell that are critical in the maintenance, repair and remodelling of bones.
Which of the following inhibits osteoclast activity? Select ONE answer only.Your Answer:
Correct Answer: Calcitonin
Explanation:Osteoclasts are a type of bone cell that breaks down bone tissue. This is a critical function in the maintenance, repair and remodelling of bones. The osteoclast disassembles and digests the composite of hydrated protein and minerals at a molecular level by secreting acid and collagenase. This process is known as bone resorption and also helps to regulate the plasma calcium concentration.
Osteoclastic activity is controlled by a number of hormones:
1,25-dihydroxycholecalciferol increases osteoclastic activity
Parathyroid hormone increases osteoclastic activity
Calcitonin inhibits osteoclastic activity
Bisphosphonates are a class of drug that slow down and prevent bone damage. They are osteoclast inhibitors. -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 79
Incorrect
-
A 22-year-old with a history of brittle asthma is brought to the ED by her partner. She is wheezing and very short of breath and her condition is deteriorating rapidly. Following a series of nebulisations, hydrocortisone and IV magnesium sulphate, she is taken to resus and the intensive care team is called to review her. She is severely hypoxic and confused and a decision is made to intubate her.
Which of these drugs is ideal as an induction agent in this patient?Your Answer:
Correct Answer: Ketamine
Explanation:Only about 2% of asthma attacks requires intubation and most severe cases are managed with non-invasive ventilation techniques.
Though life-saving in the crashing asthmatic, intubation in asthmatic patients is associated with significant morbidity and mortality and is risky. Indications for intubation in asthmatic patients include:
Severe hypoxia
Altered mental state
Respiratory or cardiac arrest
Failure to respond to medicationsKetamine (1-2 mg/kg) is the preferred induction agent. It has bronchodilatory properties and does not cause hypotension.
Propofol poses a risk of hypotension but can also be used.
-
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 80
Incorrect
-
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.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 81
Incorrect
-
Regarding the phases of gastric secretion, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: A high pH in the stomach inhibits gastrin secretion.
Explanation:A low pH in the stomach inhibits gastrin secretion, therefore when the stomach is empty or when acid has been secreted for some time after food has entered it, there is inhibition of acid secretion. However, when food first enters the stomach, the pH rises, and this leads to release of the inhibition and causes a maximum secretion of gastrin. Thus gastric acid secretion is self-regulating.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 82
Incorrect
-
Which one of these equations best defines lung compliance?
Your Answer:
Correct Answer: Change in volume / change in pressure
Explanation:Lung compliance is defined as change in volume per unit change in distending pressure.
Lung compliance is calculated using the equation:
Lung compliance = ΔV / ΔP
Where:
ΔV is the change in volume
ΔP is the change in pleural pressure.Static compliance is lung compliance in periods without gas flow, and is calculated using the equation:
Static compliance = VT / Pplat − PEEP
Where:
VT = tidal volume
Pplat = plateau pressure
PEEP = positive end-expiratory pressure -
This question is part of the following fields:
- Physiology
- Respiratory Physiology
-
-
Question 83
Incorrect
-
A patient had a left Colles' fracture, which you were able to repair. It was their second fragility fracture this year, and you'd like to provide them some tips on how to keep their bones healthy.
What percentage of the calcium in the body is kept in the bones? Only ONE response is acceptable.Your Answer:
Correct Answer: 99%
Explanation:Calcium is stored in bones for nearly all of the body’s calcium, but it is also found in some cells (most notably muscle cells) and the blood. The average adult diet comprises roughly 25 mmol of calcium per day, of which the body absorbs only about 5 mmol.
-
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 84
Incorrect
-
Which of the following is typically used in diabetes mellitus as the cut-off to define hypoglycaemia?
Your Answer:
Correct Answer: < 4.0 mmol/L
Explanation:Hypoglycaemia is defined as plasma glucose of less than 4 mmol/L.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 85
Incorrect
-
Identify the type of graph described below:
This graph is a scatter plot of the effect estimates from individual studies against some measure of each study's size or precision.
Your Answer:
Correct Answer: Funnel plot
Explanation:A funnel plot is a scatter plot of the effect estimates from individual studies against some measure of each study’s size or precision. The standard error of the effect estimate is often chosen as the measure of study size and plotted on the vertical axis with a reversed scale that places the larger, most powerful studies towards the top. The effect estimates from smaller studies should scatter more widely at the bottom, with the spread narrowing among larger studies. In the absence of bias and between study heterogeneity, the scatter will be due to sampling variation alone and the plot will resemble a symmetrical inverted funnel. A triangle centred on a fixed effect summary estimate and extending 1.96 standard errors either side will include about 95% of studies if no bias is present and the fixed effect assumption (that the true treatment effect is the same in each study) is valid.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 86
Incorrect
-
Which of the following is typically a cause of a normal anion gap metabolic acidosis:
Your Answer:
Correct Answer: Diarrhoea
Explanation:FUSEDCARS can be used to remember some of the causes of a normal anion gap acidosis:
Fistula (pancreaticoduodenal)
Ureteroenteric conduit
Saline administration
Endocrine (hyperparathyroidism)
Diarrhoea
Carbonic anhydrase inhibitors (e.g. acetazolamide)
Ammonium chloride
Renal tubular acidosis
Spironolactone -
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 87
Incorrect
-
A patient with a wound infection on his right leg has reddening and oedema of the surrounding muscles. His condition has worsened considerably over the past few hours with the area now appearing blackened. There is also palpable crepitus under the skin. You suspect gas gangrene.
Which statement about Clostridium perfringens is true?Your Answer:
Correct Answer: Gas gangrene is caused by the release of an alpha-toxin
Explanation:Clostridium perfringens, a Gram-positive, anaerobic, spore forming rod-shaped, pathogenic bacterium is the most commonly associated with gas gangrene (85-90% of cases), although other species can also be implicated.
Clostridium perfringens is capsulate and produces a range of toxins. Alpha-toxin is the most important and is the cause of gas gangrene.
Gas gangrene develops when a devitalized wound becomes infected with Clostridium perfringens spores from the environment. The spores germinate and multiplies in the ischaemic conditions, releasing toxins, which further damage tissues.
Usually, the clinical features of gas gangrene appear within 24 hours of injury.
Clostridium perfringens spores are not destroyed by cooking. During slow cooling and unrefrigerated storage, they germinate to form vegetative cells.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 88
Incorrect
-
Regarding water and electrolyte absorption in the small intestine, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Na+ enters the cell across the apical membrane against its concentration gradient by both membrane channels and transporter protein mechanisms.
Explanation:As the contents of the intestine are isotonic with body fluids and mostly have the same concentration of the major electrolytes, their absorption is active. Water cannot be moved directly, but follows osmotic gradients set up by the transport of ions, primarily mediated by the sodium pump.Na+/K+ ATPase located on the basolateral membrane of the epithelial cells pumps three Na+ ions from the cell in exchange for two K+ ions, against their respective concentration gradients. This leads to a low intracellular concentration of Na+ and a high intracellular concentration of K+. The low intracellular concentration of Na+ ensures a movement of Na+ from the intestinal contents into the cell down its concentration gradient by both membrane channels and transporter protein mechanisms. Na+ is then rapidly pumped again by the basolateral sodium pump. K+ leaves the cell across the basolateral membrane down its concentration gradient linked to an outward movement of Cl- against its concentration gradient (Cl- having entered the cell across the luminal membrane down its concentration gradient).
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 89
Incorrect
-
Which of the following movements does the iliacus muscle produce?
Your Answer:
Correct Answer: Flexion of the thigh at the hip joint
Explanation:The iliacus flexes the thigh at the hip joint when the trunk is stabilised. It flexes the trunk against gravity when the body is supine.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 90
Incorrect
-
A 17-year-old male patient diagnosed with cystic fibrosis is experiencing shortness of breath, coughing, and flu-like symptoms. His X-ray results shows atelectasis, or collapsed lung, specifically in his lower right lung. All of the following statements are true regarding collapsed lungs, except for which one.
Your Answer:
Correct Answer: Atelectasis is an example of a perfusion defect
Explanation:Atelectasis is a complete or partial collapse of the lung. It occurs when the alveoli deflate or are filled with alveolar fluid. It is considered a ventilation defect of the alveoli due to cystic fibrosis. It is not a perfusion defect. A perfusion defect will produce pathological dead space in which the lung alveoli are ventilated adequately but are not perfused, and there is no gas exchange. While with atelectasis, the alveoli remain perfused. However, there is impaired oxygen delivery and intrapulmonary shunting of blood will be present in the collapsed area. Since there is no exchange of gas at the capillary-alveolar interface of the collapsed segments, the pulmonary capillary blood will have similar PO2 and PCO2.
-
This question is part of the following fields:
- Physiology
- Respiratory Physiology
-
-
Question 91
Incorrect
-
Which of the following risk ratios indicates no difference in risk between two groups:
Your Answer:
Correct Answer: 1
Explanation:A risk ratio of 1 indicates no difference in risk between groups.If the risk ratio of an event is > 1, the rate of that event is increased in the exposed group compared to the control group.If the risk ratio is < 1, the rate of that event is reduced in the exposed group compared to the control group.
-
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 92
Incorrect
-
A 65-year-old man complains of severe vertigo, nausea, and tinnitus. Upon presenting himself to the emergency room, it was observed that he is exhibiting ataxia, right-sided loss of pain and temperature sense on the face, and left-sided sensory loss to the body. An MRI and CT scan was ordered and the results showed that he is suffering from a right-sided stroke.
Branches of which of the following arteries are most likely implicated in the case?Your Answer:
Correct Answer: Basilar artery
Explanation:The lateral pontine syndrome occurs due to occlusion of perforating branches of the basilar and anterior inferior cerebellar (AICA) arteries. It is also known as Marie-Foix syndrome or Marie-Foix-Alajouanine syndrome. It is considered one of the brainstem stroke syndromes of the lateral aspect of the pons.
It is characterized by ipsilateral limb ataxia, loss of pain and temperature sensation of the face, facial weakness, hearing loss, vertigo and nystagmus, hemiplegia/hemiparesis, and loss of pain and temperature sensation.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 93
Incorrect
-
Among the following infectious diseases, which is typically considered to have an incubation period of 3 weeks and longer?
Your Answer:
Correct Answer: Infectious mononucleosis
Explanation:Infectious mononucleosis is caused by Epstein-Barr virus (EBV). The incubation period for EBV varies from 2 weeks to 2 months.
The usual incubation period for rubella is 14 days; with a range of 12 to 23 days.
Gonorrhoea has a short incubation period of approximately 2 to 7 days.
The mumps virus can be isolated from infected saliva and swabs rubbed over the Stensen’s duct from 9 days before onset of symptoms until 8 days after parotitis appears.
Scarlet fever, which appears within 1 to 2 days after bacterial infection, is characterized by a diffuse red rash that appears on the upper chest and spreads to the trunk and extremities. The rash disappears over the next 5 to
7 days and is followed by desquamation. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 94
Incorrect
-
You proceed to administer lorazepam intravenously to a 21-year-old patient with status epilepticus. Which of the following best describes lorazepam's action?
Your Answer:
Correct Answer: Potentiates effect of GABA
Explanation:Lorazepam is a type of benzodiazepine.
Benzodiazepines are gamma-aminobutyric acid (GABA) receptor agonists with sedative, hypnotic, anxiolytic, anticonvulsant, and muscle relaxant characteristics that promote inhibitory synaptic transmission across the central nervous system.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 95
Incorrect
-
Regarding dynamic compression of the airways, which of the following statements is CORRECT:
Your Answer:
Correct Answer: It occurs during forced expiration.
Explanation:Dynamic compression occurs because as the expiratory muscles contract during forced expiration, all the structures within the lungs, including the airways, are compressed by the positive intrapleural pressure. Consequently the smaller airways collapse before the alveoli empty completely and some air remains within the lungs (the residual volume). Physiologically this is important as a completely deflated lung with collapsed alveoli requires significantly more energy to inflate. Dynamic compression does not occur in normal expiration because the intrapleural pressure is negative throughout the whole cycle.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 96
Incorrect
-
Antidiuretic hormone (ADH) levels are found to be increased in a young lady with unexplained hyponatraemia.
Which of the following is a result of the release of ADH?Your Answer:
Correct Answer: Small volumes of concentrated urine
Explanation:ADH, or antidiuretic hormone, is a hormone that regulates water and electrolyte balance. It is released in response to a variety of events, the most important of which are higher plasma osmolality or lower blood pressure. ADH increases plasma volume and blood pressure via acting on the kidneys and peripheral vasculature.
ADH causes extensive vasoconstriction by acting on peripheral V1 Receptors.ADH binds to B2 Receptors in the terminal distal convoluted tubule and collecting duct of the kidney, increasing transcription and aquaporin insertion in the cells that line the lumen. Aquaporins are water channels that allow water to pass through the tubule and into the interstitial fluid via osmosis, lowering urine losses.
The permeability of the distal collecting duct (the section within the inner medulla) to urea is likewise increased by ADH. More urea travels out of the tubule and into the peritubular fluid, contributing to the counter current multiplier, which improves the Loop of Henle’s concentrating power.Overall, there is enhanced urea and water reabsorption in the presence of ADH, resulting in modest amounts of concentrated urine. There is minimal urea and water reabsorption in the absence of ADH, resulting in huge amounts of dilute urine.
-
This question is part of the following fields:
- Physiology
- Renal Physiology
-
-
Question 97
Incorrect
-
Which coronary artery is mostly likely affected if an ECG shows ST segment elevation in leads II, III and aVF, and ST segment depression in V1-V3?
Your Answer:
Correct Answer: Right coronary artery
Explanation:A posterior wall MI occurs when posterior myocardial tissue (now termed inferobasilar), usually supplied by the posterior descending artery — a branch of the right coronary artery in 80% of individuals — acutely loses blood supply due to intracoronary thrombosis in that vessel. This frequently coincides with an inferior wall MI due to the shared blood supply.
The ECG findings of an acute posterior wall MI include the following:
1. ST segment depression (not elevation) in the septal and anterior precordial leads (V1-V4). This occurs because these ECG leads will see the MI backwards; the leads are placed anteriorly, but the myocardial injury is posterior.
2. A R/S wave ratio greater than 1 in leads V1 or V2.
3. ST elevation in the posterior leads of a posterior ECG (leads V7-V9). Suspicion for a posterior MI must remain high, especially if inferior ST segment elevation is also present.
4. ST segment elevation in the inferior leads (II, III and aVF) if an inferior MI is also present.The following ECG leads determine the location and vessels involved in myocardial infarction:
ECG Leads Location Vessel involved
V1-V2 Septal wall Left anterior descending
V3-V4 Anterior wall Left anterior descending
V5-V6 Lateral wall Left circumflex artery
II, III, aVF Inferior wall Right coronary artery (80%) or Left circumflex artery (20%)
I, aVL High lateral wall Left circumflex artery
V1, V4R Right ventricle Right coronary artery
V7-V9 Posterior wall Right coronary artery -
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 98
Incorrect
-
On his stool culture, a patient with a diarrhoeal illness grows Escherichia coli.
What SINGLE statement about Escherichia coli is true?
Your Answer:
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.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 99
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:
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.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 100
Incorrect
-
Which of the following nerves supplies the abductor pollicis brevis?
Your Answer:
Correct Answer: The recurrent branch of the median nerve
Explanation:Abductor pollicis brevis is innervated by the recurrent (thenar) branch of median nerve (root value C8 and T1).
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 101
Incorrect
-
A 62-year-old woman is brought to the Emergency Department as she is acutely unwell. Her attendants inform you that she was recently started on lithium as a mood stabilizer.
You instantly send a blood sample to check for lithium levels.
What is the usual therapeutic range for lithium?Your Answer:
Correct Answer: 0.4-0.8 mmol/l
Explanation:Lithium is the drug of choice for recurrent bipolar illness but should be carefully monitored as it has a very low therapeutic index. The normal therapeutic range is 0.4-0.8 mmol/l.
The lower end of the range is usually the target for the elderly and as maintenance therapy. Toxicity is usually seen at levels >1.5 mmol/l. Samples should be taken 12 hours after the dose, and levels should be checked one week after starting therapy and one week after every change in dosage.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 102
Incorrect
-
All of the following statements regarding metronidazole are correct except:
Your Answer:
Correct Answer: Metronidazole reduces the anticoagulant effect of warfarin.
Explanation:The anticoagulant effect of warfarin is enhanced by metronidazole. If use of both cannot be avoided, one must consider appropriately reducing the warfarin dosage. With alcohol, metronidazole can cause a disulfiram-like reaction, with symptoms like flushing, headaches, dizziness, tachypnoea and tachycardia, nausea and vomiting. The common side effects of metronidazole include a metallic taste and gastrointestinal irritation, in particular nausea and vomiting. These side effects are more common at higher doses. This drug has high activity against anaerobic bacteria and protozoa, and is well absorbed orally. For severe infections, the intravenous route is normally reserved.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 103
Incorrect
-
Which of the following nerves supplies innervation to the extensor hallucis longus?
Your Answer:
Correct Answer: Deep peroneal nerve
Explanation:Extensor hallucis longus is innervated by the deep fibular nerve (root value L5 and S1).
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 104
Incorrect
-
What is the primary function of the mitochondria?
Your Answer:
Correct Answer: The production of the cell's supply of chemical energy
Explanation:The mitochondria is responsible for the production of the cell’s supply of chemical energy. It does this by using molecular oxygen, sugar and small fatty acid molecules to generate adenosine triphosphate (ATP) by a process ss known as oxidative phosphorylation. An enzyme called ATP synthase is required.
Transcription of ribosomal RNA occurs in the nucleolus
Production of messenger RNA occur in the nucleus
Production of lysosome occurs in the Golgi apparatus
The post-translational processing of newly made proteins occurs in the endoplasmic reticulum
-
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
-
-
Question 105
Incorrect
-
A patient is complaining of painless jaundice. His bilirubin levels are abnormally high.
Which of the following statements about bile is correct?Your Answer:
Correct Answer: Bile acids are amphipathic
Explanation:The liver produces bile on a constant basis, which is then stored and concentrated in the gallbladder. In a 24-hour period, around 400 to 800 mL of bile is generated.
Bile is involved in the following processes:
Fats are broken down into fatty acids.
Waste products are eliminated.
Cholesterol homeostasis is the balance of cholesterol in the body.The enteric hormones cholecystokinin and secretin are primarily responsible for bile secretion. When chyme from an unprocessed meal enters the small intestine, they are released, and they play the following function in bile secretion and flow:
Cholecystokinin promotes gallbladder and common bile duct contractions, allowing bile to reach the intestine.
Secretin enhances the secretion of bicarbonate and water by biliary duct cells, increasing the amount of bile and its flow into the gut.Bile acids have a hydrophobic and hydrophilic area, making them amphipathic. Bile acids’ amphipathic nature allows them to perform the following crucial functions:
Emulsification of lipid aggregates increases the surface area of fat and makes it easier for lipases to digest it.
Lipid solubilization and transport: solubilizes lipids by creating micelles, which are lipid clumps that float in water. -
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
-
-
Question 106
Incorrect
-
Which of the following cytokines is important for the maintenance of granulomatous inflammation:
Your Answer:
Correct Answer: TNF-alpha
Explanation:Granulomatous inflammation is a distinctive pattern of chronic inflammation that is encountered in a limited number of infectious and some non-infectious conditions. Briefly, a granuloma is a cellular attempt to contain an offending agent that is difficult to eradicate. In this attempt, there is often strong activation of T lymphocytes leading to macrophage activation, which can cause injury to normal tissues. IL-1 is important in initiating granuloma formation, IL-2 can cause them to enlarge and TNF-α maintains them.
-
This question is part of the following fields:
- Inflammatory Responses
- Pathology
-
-
Question 107
Incorrect
-
Which of the following microbes attaches to host cells by its haemagglutinin antigen:
Your Answer:
Correct Answer: Influenza virus
Explanation:Hemagglutinin (HA) or Haemagglutinin (BE) is an antigenic glycoprotein found on the surface of the influenza viruses. It is responsible for binding the virus to the cell that is being infected. The name hemagglutinin comes from the protein’s ability to cause red blood cells (erythrocytes) to clump together (agglutinate) in vitro.
-
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 108
Incorrect
-
Which of the following side effects is more common of etomidate than other intravenous induction agents:
Your Answer:
Correct Answer: Extraneous muscle movements
Explanation:Etomidate is associated with a high incidence of extraneous muscle movements, which can be minimised by an opioid analgesic or a short-acting benzodiazepine given prior to induction. Etomidate causes less hypotension than thiopental sodium and propofol during induction. Etomidate is associated with rapid recovery without a hangover effect. The rate of respiratory depression and tachycardia is not higher in etomidate.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 109
Incorrect
-
A 66-year-old male presents to his family physician with the complaint of increasing fatigue and lethargy, along with itching, especially after a hot bath. He also complains of increased sweating and dizziness. On examination, he has a plethoric appearance. Abdominal examination shows the presence of splenomegaly. A basic panel of blood tests is ordered in which her Hb comes out to be 17 g/dL.
Which one of the following treatment options will be most suitable in this case?Your Answer:
Correct Answer: Venesection
Explanation:The clinical and laboratory findings, in this case, support a diagnosis of polycythaemia vera. A plethoric appearance, lethargy, splenomegaly and itching are common in this disease. Patients may also have gouty arthritis, Budd-Chiari syndrome, erythromelalgia, stroke, myocardial infarction or DVT. The average age for diagnosis of Polycythaemia Vera is 65-74 years. It is a haematological malignancy in which there is overproduction of all three cell lines. Venesection is the treatment of choice as it would cause a decrease in the number of red blood cells within the body.
Erythropoietin is given in patients with chronic renal failure as they lack this hormone. Administration of erythropoietin in such patients causes stimulation of the bone marrow to produce red blood cells.
Desferrioxamine is a chelating agent for iron and is given to patients with iron overload due to repeated blood transfusions, e.g. in thalassemia patients.
Penicillamine is a chelating agent for Copper, given as treatment in Wilson’s disease.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 110
Incorrect
-
Regarding renal clearance, which of the following statements is CORRECT:
Your Answer:
Correct Answer: The MDRD equation uses plasma creatinine to estimate the GFR making an adjustment for age, sex and race.
Explanation:Clearance is defined as the volume of plasma that is cleared of a substance per unit time. Inulin clearance is the gold standard for measurement of GFR but creatinine clearance is typically used instead. Creatinine is freely filtered and not reabsorbed, but there is a little creatinine tubular secretion. In practice, GFR is usually estimated from the plasma creatinine using a formula e.g. the MDRD equation making an adjustment for age, sex and race.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 111
Incorrect
-
A patient suffers a stab wound to the neck. The entry point of the blade is situated within the posterior triangle of the neck.
Which of the following muscles is LEAST likely to be involved? Select ONE answer only.Your Answer:
Correct Answer: Sternohyoid
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
-
-
Question 112
Incorrect
-
Which of the following movements is controlled by the pectoralis major muscle?
Your Answer:
Correct Answer: Flexion, adduction and medial rotation of the humerus
Explanation:The pectoralis major is a muscle that runs across the top of the chest and connects to a ridge on the back of the humerus (the bone of the upper arm).
Adduction, or lowering, of the arm (opposed to the deltoideus muscle) and rotation of the arm forward around the axis of the body are two of its main functions.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 113
Incorrect
-
A 39-year-old man who is suffering from a bacterial infection require antibiotic treatment. You need to figure out which antibiotic is most suitable. Listed below are antimicrobial drugs.
Which one is a nucleic acid synthesis inhibitor?
Your Answer:
Correct Answer: Ciprofloxacin
Explanation:Ciprofloxacin and other quinolone antibiotics work by blocking DNA gyrase, an enzyme that compresses bacterial DNA into supercoils, as well as a type II topoisomerase, which is required for bacterial DNA separation. As a result, they prevent nucleic acid synthesis.
The following is a summary of the many modes of action of various types of antimicrobial agents:Action Mechanisms- Examples:
Cell wall production is inhibited
Vancomycin
Vancomycin
CephalosporinsThe function of the cell membrane is disrupted
Nystatin
Polymyxins
Amphotericin BInhibition of protein synthesis
Chloramphenicol
Macrolides
Aminoglycosides
TetracyclinesNucleic acid synthesis inhibition
Quinolones
Trimethoprim
Rifampicin
5-nitroimidazoles
Sulphonamides
Anti-metabolic activity
Isoniazid -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 114
Incorrect
-
A 78-year-old man develops renal impairment and hearing loss after inpatient management for sepsis.
Which of these antibiotics is most likely to have been used?Your Answer:
Correct Answer: Gentamicin
Explanation:Gentamicin, an aminoglycoside antibiotic, acts by binding to the 30S subunit of the bacterial ribosome inhibiting the binding of aminoacyl-tRNA, and thus prevents initiation of protein synthesis.
Two of its most notable side effects are reversible nephrotoxicity(caused by the inhibition of protein synthesis in renal cells, which causes acute tubular necrosis) and hearing loss (caused by damage to the vestibular apparatus of the inner ear).
Both side effects are dose-related and occur commonly in the elderly.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 115
Incorrect
-
Regarding inflammatory bowel disease, acute mild to moderate disease of the rectum or rectosigmoid should be treated initially with:
Your Answer:
Correct Answer: Local aminosalicylate
Explanation:Acute mild to moderate disease affecting the rectum (proctitis) or the rectosigmoid is treated initially with local application of an aminosalicylate; alternatively, a local corticosteroid can be used but it is less effective. A combination of a local aminosalicylate and a local corticosteroid can be used for proctitis that does not respond to a local aminosalicylate alone.
-
This question is part of the following fields:
- Gastrointestinal
- Pharmacology
-
-
Question 116
Incorrect
-
Regarding disseminated intravascular coagulation (DIC), which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Thrombocytosis results in widespread platelet aggregation.
Explanation:DIC is characterised by a widespread inappropriate intravascular deposition of fibrin with consumption of coagulation factors and platelets. This may occur as a consequence of many disorders that release procoagulant material into the circulation or cause widespread endothelial damage or platelet aggregation. Increased activity of thrombin in the circulation overwhelms its normal rate of removal by natural anticoagulants. In addition to causing increased deposition of fibrin in the microcirculation and widespread platelet aggregation to the vessels, intravascular thrombin formation interferes with fibrin polymerisation. Intense fibrinolysis is stimulated by thrombi on vascular walls and the release of fibrin degradation products again interferes with fibrin polymerisation. The combined action of thrombin and plasmin causes depletion of fibrinogen and all coagulation factors, compounded by thrombocytopaenia caused by platelet consumption.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 117
Incorrect
-
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:
Correct 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.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 118
Incorrect
-
Which of the following is NOT typically associated with eosinophilia:
Your Answer:
Correct Answer: Whooping cough
Explanation:An eosinophil leucocytosis is defined as an increase in blood eosinophils above 0.4 x 109/L.It is most frequently due to:
Allergic diseases (e.g. bronchial asthma, hay fever, atopic dermatitis, urticaria)
Parasites (e.g. hookworm, ascariasis, tapeworm, schistosomiasis)
Skin diseases (e.g. psoriasis, pemphigus, urticaria, angioedema)
Drug sensitivity -
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 119
Incorrect
-
Which of the following is NOT a typical clinical feature of sickle cell disease:
Your Answer:
Correct Answer: Neutropaenia
Explanation:Features of sickle cell disease include:
Anaemia (symptoms are usually mild because the O2 dissociation curve of Hb S is shifted to the right)
Vaso-occlusive crisis
Visceral sequestration crisis
Aplastic crisisIncreased susceptibility to infection
Other clinical features: Pigment gallstones with cholecystitis
Chronic leg ulcers
Avascular necrosis of the femoral and humeral heads or other bones
Cardiomyopathy
Pulmonary hypertension
Proliferative retinopathy
Priapism
Renal papillary necrosis
Stroke -
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 120
Incorrect
-
A patient with history of weight loss and diarrhoea was found out to have Giardia lamblia in her stool since returning from a holiday to Nepal.
Which of the following statements is considered true regarding the life cycle of Giardia lamblia?Your Answer:
Correct Answer: Trophozoites attach to the intestinal wall via a specialised sucking disc
Explanation:Cysts are resistant forms and are responsible for transmission of giardiasis. Both cysts and trophozoites can be found in the faeces (diagnostic stages). The cysts are hardy and can survive several months in cold water. Infection occurs by the ingestion of cysts in contaminated water, food, or by the faecal-oral route (hands or fomites).
In the small intestine, excystation releases trophozoites (each cyst produces two trophozoites).
Trophozoites multiply by longitudinal binary fission, remaining in the lumen of the proximal small bowel where they can be free or attached to the mucosa by a ventral sucking disk.
Encystation occurs as the parasites transit toward the colon. The cyst is the stage found most commonly in non diarrheal faeces.
Because the cysts are infectious when passed in the stool or shortly afterward, person-to-person transmission is possible. While animals are infected with Giardia, their importance as a reservoir is unclear. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
-
Question 121
Incorrect
-
A patient presents with a lump for a dermatological examination. There is a circumscribed skin elevation measuring 0.3 cm in diameter seen on examination.
Which one of these best describes the lump you have found on examination?Your Answer:
Correct Answer: Papule
Explanation:A papule is a solid, well circumscribed, skin elevation measuring less than 0.5 cm in diameter.
A nodule is a solid, well circumscribed, raised area that lies in or under the skin and measures greater than 0.5 cm in diameter. They are usually painless.
A bulla is a visible collection of clear fluid measuring greater than 0.5 cm in diameter.
A furuncle, or boil, is a pyogenic infection of the hair follicle commonly caused by infection with Staphylococcus aureus.
A pustule is a small visible skin elevation containing an accumulation of pus.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 122
Incorrect
-
What is the main mechanism of action of dopamine as an inotropic sympathomimetic:
Your Answer:
Correct Answer: Beta1-receptor agonist
Explanation:Dopamine is a neurotransmitter and a metabolic precursor of the catecholamines. It acts on beta1-receptors in cardiac muscle increasing cardiac contractility, and increases renal perfusion by stimulating dopamine receptors in the renal vasculature. This is of benefit in cardiogenic shock where deterioration of renal function is common.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 123
Incorrect
-
A 26-year-old female cuts her hand on a knife while preparing dinner but the bleeding stops within a few minutes.
Which one of the following cells will be among the first to be present at the wound site to be involved in haemostasis?Your Answer:
Correct Answer: Platelets
Explanation:Platelets are the first cells to be attracted to the wound site due to the release of the Von Willebrand factor from the damaged endothelium. Platelets, in turn, release cytokines such as platelet-derived growth factor, which will attract other inflammatory cells to the wound site.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 124
Incorrect
-
You are seeing a child with known mitochondrial disease who has presented breathlessness and cough. Which of the following best describes the function of mitochondria:
Your Answer:
Correct Answer: Energy production
Explanation:Mitochondria are membrane-bound organelles that are responsible for the production of the cell’s supply of chemical energy. This is achieved by using molecular oxygen to utilise sugar and small fatty acid molecules to generate adenosine triphosphate (ATP). This process is known as oxidative phosphorylation and requires an enzyme called ATP synthase. ATP acts as an energy-carrying molecule and releases the energy in situations when it is required to fuel cellular processes. Mitochondria are also involved in other cellular processes, including Ca2+homeostasis and signalling. Mitochondria contain a small amount of maternal DNA.
Mitochondria have two phospholipid bilayers, an outer membrane and an inner membrane. The inner membrane is intricately folded inwards to form numerous layers called cristae. The cristae contain specialised membrane proteins that enable the mitochondria to synthesise ATP. Between the two membranes lies the intermembrane space, which stores large proteins that are required for cellular respiration. Within the inner membrane is the perimitochondrial space, which contains a jelly-like matrix. This matrix contains a large quantity of ATP synthase.
Mitochondrial disease, or mitochondrial disorder, refers to a group of disorders that affect the mitochondria. When the number or function of mitochondria in the cell are disrupted, less energy is produced and organ dysfunction results. -
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 125
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:
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.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 126
Incorrect
-
Regarding likelihood ratios, which of the following statements is INCORRECT:
Your Answer:
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.
-
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 127
Incorrect
-
Lidocaine's mechanism of action as a local aesthetic is as follows:
Your Answer:
Correct Answer: Blocks influx of Na+ through voltage-gated Na+ channels
Explanation:Local anaesthetics prevent generation/conduction of nerve impulses by reducing sodium permeability and increasing action potential threshold; inhibits depolarization, which results in blockade of conduction
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 128
Incorrect
-
The blood test reports of a 56-year-old female are sent for your review. She seems acutely sick and has had multiple infections over the past few months. Her complete blood count report shows neutropenia.
Which one of the following options is true with regards to neutropenia?Your Answer:
Correct Answer: It can be caused by both radiotherapy and chemotherapy
Explanation:A total neutrophil count of less than 2 x 109/L is defined as neutropenia. It can be caused by the following:
1. viral infections
2. SLE
3. RA
4. hypersplenism
5. chemo- and radiotherapy
6. vitamin B12 and folate deficiency
7. drug reactions -
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 129
Incorrect
-
A 25-year-old man suffers from a shoulder injury that damaged the nerve that innervates the infraspinatus muscle.
Which of the following nerves may most likely be affected?Your Answer:
Correct Answer: The suprascapular nerve
Explanation:The suprascapular nerve (C5-C6) innervates the infraspinatus. It originates at the superior trunk of the brachial plexus. It runs laterally across the lateral cervical region to supply the infraspinatus and also the supraspinatus.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 130
Incorrect
-
A patient is found to be anaemic. Which one of the following blood results would favour a diagnosis of anaemia of chronic disease rather than iron deficiency:
Your Answer:
Correct Answer: Low total iron binding capacity (TIBC)
Explanation:Anaemia of chronic disease is one of the most common causes of normocytic anaemia. The anaemia is usually mild (Hb > 90 g/L) and non-progressive. Anaemia of chronic disease is usually associated with low serum iron, low transferrin saturation, and a low total iron binding capacity (TIBC) with normal or raised ferritin which differentiates it from iron deficiency anaemia.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 131
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:
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
-
-
Question 132
Incorrect
-
Which of the following is true about the extensor carpi radialis longus?
Your Answer:
Correct Answer: It assists with abduction of the hand at the wrist
Explanation:The majority of extensor carpi radialis longus originates from the lateral supracondylar ridge of humerus (distal third) and anterior aspect of the lateral intermuscular septum of the arm. A small portion of its fibres originate from the common extensor tendon attached to the lateral epicondyle of humerus. The fibres unite into a muscle belly which extends approximately to the middle of the forearm. The muscle belly is then replaced by a flat tendon that travels distally along the lateral surface of the radius, together with the tendon of extensor carpi radialis brevis. Both tendons course towards the radial styloid process, deep to the tendons of abductor pollicis longus and extensor pollicis brevis muscles. Proximal to the wrist, the tendons of extensor carpi radialis longus and brevis pass behind the radial styloid process within a common synovial sheath and continue along the radial groove deep to the extensor retinaculum of the wrist. At this level, the tendon of extensor carpi radialis longus is crossed by the tendon of extensor pollicis longus, after which it inserts on the posterior aspect of the base of the second metacarpal bone. Some tendon slips can insert into the first and third metacarpal bones.
Extensor carpi radialis longus receives innervation from the radial nerve, with contributions mainly from spinal nerves C5-C8. The radial nerve is a branch of the brachial plexus.
Extensor carpi radialis longus receives blood supply mainly from the radial artery. It directly supplies the distal part of the muscle, while the rest of the muscle receives blood from one of its radial recurrent branches. The brachial artery also supplies a small portion of the muscle via the radial collateral artery.
Extensor carpi radialis longus primarily acts on the wrist joint to produce two major actions: (1) wrist extension by working synergistically with extensor carpi radialis brevis and extensor carpi ulnaris, and (2) hand abduction (radial deviation), with the help of flexor carpi radialis.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 133
Incorrect
-
Common causes of exudates are infection, pericarditis, and malignancy.
Which one statement about exudates is true?Your Answer:
Correct Answer: LDH levels are usually high
Explanation:An exudate is an inflammatory fluid emanating from the intravascular space due to changes in the permeability of the surrounding microcirculation.
Exudates are cloudy. It has high LDH levels, serum protein ratio >0.5, protein content >2.9g/dl, specific gravity of >1.020 and a serum-ascites albumin gradient (SAAG) of <1.2g/dl.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 134
Incorrect
-
A 70-year-old woman presents with exacerbation of her chronic obstructive pulmonary disease (COPD), increased cough, wheeze and chest tightness. On examination, she is tachypnoeic and oxygen saturation is 86%. You plan to administer supplemental oxygen.
Which oxygen delivery system is most appropriate to use initially?Your Answer:
Correct Answer: Venturi mask
Explanation:In life-threatening emergencies, oxygen should be started immediately otherwise, it should be prescribed like any other drug. The prescription should include a target saturation range.
Until blood gases can be measured, initial oxygen should be administered using a controlled concentration of 24% or 28%.
The ideal mask is a Venturi mask.The other mask are not ideal for initial use
-
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 135
Incorrect
-
Question 136
Incorrect
-
A newborn baby girl is delivered vaginally to a 19-year old female, however with complications due to cephalopelvic disproportion. Upon examination by the attending paediatrician, there is a notable 'claw hand' deformity of the left, and sensory loss of the ulnar aspect of the left distal upper extremity.
What is the most probable diagnosis of the case above?Your Answer:
Correct Answer: Klumpke’s palsy
Explanation:Klumpke palsy, named after Augusta Dejerine-Klumpke, is a neuropathy involving the lower brachial plexus. In contrast, the more common Erb–Duchenne palsy involves the more cephalic portion of the brachial plexus C5 to C6. The brachial plexus is a bundle of individual nerves that exit between the anterior and middle scalene muscles in the anterior lateral and basal portion of the neck. Although the most common anatomical presentation of the brachial plexus is between the anterior and middle scalene, there are variations, with the most common being penetration of the anterior scalene. The main mechanism of injury to the lower brachial plexus is hyper-abduction traction, and depending on the intensity, it will lead to signs and symptoms consistent with a neurological insult.
The most common aetiology resulting in Klumpke palsy is a hyper-abduction trauma to the arm that has enough intensity to traction the lower brachial plexus. Trauma during birth can cause brachial plexus injuries, but again hyper-abduction and traction forces to the upper extremity are usually present.
The history presented by the patient usually depicts a long axis hyper-abduction traction injury with high amplitude and velocity. The typical patient presentation is a decrease of sensation along the medial aspect of the distal upper extremity along the C8 and T1 dermatome. The patient might also present myotome findings that can range from decreasing muscular strength to muscular atrophy and positional deformity. For example, if the neurological damage has led to muscular atrophy and tightening, the patient may present with a claw hand. This deformity presents a finger and wrist flexion. The patient may also describe the severe pain that starts at the neck and travels down the medial portion of the arm. One other sign of a lower brachial plexus injury is Horner syndrome; because of its approximation to the T1 nerve root, it may damage the cephalic sympathetic chain. If this happens, the patient will develop ipsilateral ptosis, anhidrosis, and miosis.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 137
Incorrect
-
You review an 18-months-old child who seems to be having a reaction following an immunisation she took earlier in the day.
Which statement concerning immunity and vaccination is true?Your Answer:
Correct Answer: The strongest immunological response is seen with natural immunity
Explanation:Vaccination induces ACTIVE adaptive immunity. Actively acquired immunity involves the development of an immune response either due to vaccination or natural exposure to a pathogen and leads to long-lasting resistance to infection.
Immediate protection is achieved with injection of immunoglobulin. The protection is transient lasting only a few weeks and is useful as post-exposure prophylaxis.
Passively acquired immunity usually leads to short-lasting resistance to infection because it does not involve a host immune response.
With inactivated bacteria, a series of primary vaccinations is usually required to induce an adequate immune response. In most cases, boosters are required to sustain adequate immunity.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 138
Incorrect
-
Regarding the lacrimal apparatus, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Lacrimal fluid is drained from the eyeball through the lacrimal punctum.
Explanation:Lacrimal fluid is drained from the eyeball through the lacrimal punctum.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 139
Incorrect
-
A patient presents with a gastrointestinal infection. Which of the following microbes attaches to gut mucosa via a specialised sucking disc:
Your Answer:
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
-
-
Question 140
Incorrect
-
Depolarisation of a neuron begins with which of the following:
Your Answer:
Correct Answer: Opening of ligand-gated Na + channels
Explanation:Action potentials are initiated in nerves by activation of ligand-gated Na+channels by neurotransmitters. Opening of these Na+channels results in a small influx of sodium and depolarisation of the negative resting membrane potential (-70 mV). If the stimulus is sufficiently strong, the resting membrane depolarises enough to reach threshold potential (generally around -55 mV), at which point an action potential can occur. Voltage-gated Na+channels open, causing further depolarisation and activating more voltage-gated Na+channels and there is a sudden and massive sodium influx, driving the cell membrane potential to about +40 mV.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 141
Incorrect
-
A 44 year old woman is brought to ED having fallen down the stairs and injured her right arm. On examination she is unable to abduct her arm normally, and has weakness of lateral rotation. She has sensory loss over the lateral aspect of her upper arm. Which of the following injuries is most likely to produce this pattern of injury:
Your Answer:
Correct Answer: Surgical neck of humerus fracture
Explanation:Damage to the axillary nerve will result in loss of abduction past about 15 degrees and weakness of lateral rotation due to paralysis of the deltoid and teres minor and loss of sensation over the regimental badge area on the upper lateral arm. The axillary nerve is most likely injured in fracture of the surgical neck of the humerus due to its course where it winds around this region together with the posterior humeral circumflex vessels.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 142
Incorrect
-
A 2nd-year medical student is solving an exam paper with questions about the immune system. She comes across a question regarding innate immunity. Innate immunity is the immunity naturally present within the body from birth.
Which ONE of the following is not a part of this type of immunity?Your Answer:
Correct Answer: Antibody production
Explanation:Innate immunity, also called non-specific immunity, refers to the components of the immune system naturally present in the body at birth.
The components of innate immunity include:
1) Natural Killer Cells
2) Neutrophils
3) Macrophages
4) Mast Cells
5) Dendritic Cells
6) Basophils.Acquired or adaptive immunity is acquired in response to infection or vaccination. Although the response takes longer to develop, it is also a more long-lasting form of immunity.
The components of this system include:
1) T lymphocytes
2) B lymphocytes
3) Antibodies -
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 143
Incorrect
-
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:
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.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 144
Incorrect
-
A 22-year-old student presents with severe headache accompanied with nausea and vomiting. Upon observation and examination, it was noted that he is febrile and Kernig's sign is positive. A diagnosis of meningitis was suspected and a lumbar puncture was to be performed.
Which of the following statements regarding meningitis is true?Your Answer:
Correct Answer: The dura mater is the outermost layer
Explanation:Meningitis is defined as the inflammation of the meninges due to an infection caused by a bacteria or a virus. Symptoms usually include stiffness of the neck, headache, and fever.
There are 3 meningeal layers that surround the spinal cord and they are the dura mater, arachnoid matter, and pia mater.The dura mater is the outermost and thickest layer out of all the 3 layers.
The arachnoid atter is the middle layer, and is very thin.
The third and deepest meningeal layer is the pia mater that is bound tightly to the surface of the spinal cord. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 145
Incorrect
-
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:
Correct 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.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 146
Incorrect
-
Regarding carbon dioxide transport in the blood, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Deoxygenated haemoglobin acts as a buffer for H+ ions.
Explanation:CO2generated in the tissues and water combine to form carbonic acid which readily dissociates to form HCO3-and H+. The first part of this reaction is very slow in plasma, but is accelerated dramatically by the enzyme carbonic anhydrase present in red blood cells. Bicarbonate is therefore formed preferentially in red cells, from which it freely diffuses down its concentration gradient into plasma where it is transported to the lungs. The red cell membrane is impermeable to H+ions which remain in the cell. To maintain electroneutrality, Cl-ions diffuse into the cell to replace HCO3-, an effect known as the chloride shift. Deoxygenated haemoglobin acts as a buffer for H+, allowing the reaction to continue.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 147
Incorrect
-
A patient with a diagnosis of HIV presents with a fever, sore throat, and general malaise and you are concerned the patient may have an AIDS defining illness.
Which one of these, according to the CDC definition, would mean a patient infected with HIV has AIDS?
Your Answer:
Correct Answer: CD4 T-cell percentage of total lymphocytes of less than 15%
Explanation:According to the CDC definition, a patient co-infected with HIV can be diagnosed with AIDS if he or she has:
A CD4 T-cell count of less than 200 cells/mm3 or;
A CD4 T-cell percentage of total lymphocytes of less than 15% or;
An AIDS defining infectionA Streptococcal throat infection is not an AIDS defining infection.
A normal CD4 count ranges from 500-1000 cells/mm3. A CD4 (not CD8) count of less than 200 cells/mm3 is AIDS defining.
The CD4 count can vary from day to day and depending upon the time that the blood test is taken. It can also be affected by the presence of other infections or illnesses. Treatment with anti-retroviral therapy should be considered at CD4 count of less than 350 cells/mm3.
Serum concentrations of the p24 antigen (the viral protein that makes up most of the core of the HIV) are usually high in the first few weeks after human immunodeficiency virus (HIV) infection and testing for p24 antigen is therefore a useful way of diagnosing very early infection.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 148
Incorrect
-
You have been asked to give a tutorial on common upper limb neurology to a group of medical students. You use the example of a man falling from a balcony onto spiked fencing, sustaining a puncture wound to the axilla. This results in an injury to the musculocutaneous nerve. Which of the following clinical features would you LEAST expect to see in this patient:
Your Answer:
Correct Answer: Weakness of forearm pronation
Explanation:Flexion of the arm and flexion and supination of the forearm are weakened but not lost entirely due to the actions of the pectoralis major and deltoid, the brachioradialis and the supinator muscles respectively. There is loss of sensation over the lateral aspect of the forearm. Forearm pronation would not be affected as this is primarily produced by the pronator quadratus and pronator teres muscles, innervated by the median nerve.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 149
Incorrect
-
In all of the following conditions, lymphocytosis typically occurs except for:
Your Answer:
Correct Answer: Corticosteroid therapy
Explanation:In infants and young children, lymphocytosis often occurs in response to infections that would normally produce a neutrophil reaction in adults.
Lymphocytosis occurs in:
1. Viral infections (e.g. infectious mononucleosis, HIV, rubella, mumps, viral hepatitis, cytomegalovirus, herpes simplex or zoster)
2. Bacterial infections (e.g. pertussis, tuberculosis, toxoplasmosis, syphilis)
3. Chronic lymphoid leukaemias
4. Acute lymphoblastic leukaemias
5. Non-Hodgkin lymphoma
6. Thyrotoxicosis -
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 150
Incorrect
-
A 7-year old boy is referred to the Paediatrics Department due to slurred speech. Upon further examination, the attending physician noted the presence of dysdiadochokinesia, intention tremors, and nystagmus. An MRI is taken, which revealed a brain tumour.
Which of the following options is the most probable diagnosis given the clinical features of the patient?Your Answer:
Correct Answer: Astrocytoma of cerebellum
Explanation:Pilocytic astrocytoma (PCA), previously known as cystic cerebellar astrocytoma or juvenile pilocytic astrocytoma, was first described in 1931 by Harvey Cushing, based on a case series of cerebellar astrocytomas; though he never used these terms but rather described a spongioblastoma. They are low-grade, and usually well-circumscribed tumours, which tend to occur in young patients. By the World Health Organization (WHO) classification of central nervous system tumours, they are considered grade I gliomas and have a good prognosis.
PCA most commonly occurs in the cerebellum but can also occur in the optic pathway, hypothalamus, and brainstem. They can also occur in the cerebral hemispheres, although this tends to be the case in young adults. Presentation and treatment vary for PCA in other locations. Glial cells include astrocytes, oligodendrocytes, ependymal cells, and microglia. Astrocytic tumours arise from astrocytes and are the most common tumour of glial origin. The WHO 2016 categorized these tumours as either diffuse gliomas or other astrocytic tumours. Diffuse gliomas include grade II and III diffuse astrocytomas, grade IV glioblastoma, and diffuse gliomas of childhood. The other astrocytic tumours group include PCA, pleomorphic xanthoastrocytoma, subependymal giant cell astrocytoma, and anaplastic pleomorphic xanthoastrocytoma.
PCA can present with symptoms secondary to the posterior fossa mass effect. This may include obstructive hydrocephalus, with resultant headache, nausea and vomiting, and papilledema. If hydrocephalus occurs before the fusion of the cranial sutures (<18-months-of-age), then an increase in head circumference will likely occur. Lesions of the cerebellar hemisphere result in peripheral ataxia, dysmetria, intention tremor, nystagmus, and dysarthria. In contrast, lesions of the vermis cause a broad-based gait, truncal ataxia, and titubation. Posterior fossa lesions can also cause cranial nerve palsies. Diplopia may occur due to abducens palsy from the stretching of the nerve. They may also have blurred vision due to papilledema. Seizures are rare with posterior fossa lesions.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
SESSION STATS - PERFORMANCE PER SPECIALTY
