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Question 1
Incorrect
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In the treatment of bradyarrhythmias with adverse characteristics or risk of asystole, what is the initial suggested dose of atropine?
Your Answer: 1 mg
Correct 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.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 2
Incorrect
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Which of the following statements is incorrect regarding the electron transfer system?
Your Answer: The electron transfer system uses NADH 2 molecules produced during glycolysis and the Krebs cycle.
Correct Answer: The electron transfer system occurs in anaerobic respiration.
Explanation:The electron transfer system is responsible for most of the energy produced during respiration. The is a system of hydrogen carriers located in the inner mitochondrial membrane. Hydrogen is transferred to the electron transfer system via the NADH2molecules produced during glycolysis and the Krebs cycle. As a result, a H+ion gradient is generated across the inner membrane which drives ATP synthase. The final hydrogen acceptor is oxygen and the H+ions and O2 combine to form water.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 3
Correct
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After reviewing a child with respiratory distress who presented to the clinic, you make a diagnosis of bronchiolitis.
What is the most common causative organism?
Your Answer: Respiratory syncitial virus
Explanation:Bronchiolitis is a common respiratory infection that occurs in infancy between the ages of 3-6 months and in the winter months. It is most commonly caused by the respiratory syncytial virus (70% of cases)
Although it can also be caused by parainfluenza virus, adenovirus, coronavirus, rhinovirus, and influenza virus, these are not the most common causes
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 4
Correct
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Regarding chronic idiopathic thrombocytopaenic purpura (ITP), which of the following statements is INCORRECT:
Your Answer: ITP is classically associated with massive splenomegaly.
Explanation:Chronic ITP is a relatively common disorder. The highest incidence is in women aged 15 – 50 years. It is the most common cause of thrombocytopaenia without anaemia or neutropaenia. It is usually idiopathic but it may been seen in association with other conditions. Platelet autoantibodies (usually IgG) result in the premature removal of platelets from the circulation by macrophages of the reticuloendothelial system. In many causes the antibody is directed against the glycoprotein IIb/IIIa or Ib complex. The normal platelet lifespan of 10 days is reduced to a few hours. Total megakaryocyte mass and platelet turnover are increased to approximately five times normal. Despite the destruction of platelets by splenic macrophages, the spleen is normally not enlarged. In fact, an enlarged spleen should lead to a search for other possible causes for the thrombocytopenia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 5
Correct
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A young patient presents with the features of an easily recognisable infectious disease.
Which of the following infectious diseases typically has an incubation period of less than 1 week? Select ONE answer only.Your Answer: Cholera
Explanation:Cholera has an incubation period of 12 hours to 6 days.
Other infectious disease that have an incubation period of less than 1 week include:
Staphylococcal enteritis (1-6 hours)
Salmonella enteritis (12-24 hours)
Botulism (18-36 hours)
Gas gangrene (6 hours to 4 days)
Scarlet fever (1-4 days)
Diphtheria (2-5 days)
Gonorrhoea (3-5 days)
Yellow fever (3-6 days)
Meningococcaemia (1-7 days)
Brucellosis has an incubation period of 7-21 days.
Measles has an incubation period of 14-18 days.
Falciparum malaria usually has an incubation period of 7-14 days. The other forms of malaria have a longer incubation period of 12-40 days.
Rubella has an incubation period of 14-21 days. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 6
Correct
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You are giving a teaching session to a group of final year medical students regarding lower limb neurology. Which of the following clinical features would be expected in an obturator nerve palsy:
Your Answer: Weakness of hip adduction
Explanation:Damage to the obturator nerve results in weak adduction of the hip with lateral swinging of the limb during walking due to unopposed abduction.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 7
Incorrect
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After a work-related accident, a 33-year old male is taken to the emergency room with difficulty in adduction and flexion of his left arm at the glenohumeral joint. The attending physician is suspects involvement of the coracobrachialis muscle.
The nerve injured in the case above is?Your Answer: The suprascapular nerve
Correct Answer: The musculocutaneous nerve
Explanation:The coracobrachialis muscle is innervated by the musculocutaneous nerve (C5-C7) a branch of the lateral cord of the brachial plexus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 8
Correct
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A 37-year-old man presents with breathlessness on exertion and dry cough, fever for the past 2 days and bilateral pleuritic chest pain.
He had been diagnosed with HIV and commenced on HAART but due to side effects, his compliance has been poor over the last few months.
On examination you note scattered crackles and wheeze bilaterally, cervical and inguinal lymphadenopathy, and oral thrush. At rest his oxygen saturation is 97% but this drops to 87% on walking. There is perihilar fluffy shadowing seen on his chest X-ray.
Which of these organisms is the most likely causative organism?
Your Answer: Pneumocystis jirovecii
Explanation:All of the organisms listed above can cause pneumonia in immunocompromised individuals but the most likely cause in this patient is Pneumocystis jirovecii.
It is a leading AIDS-defining infection in HIV-infected individuals and causes opportunistic infection in immunocompromised individuals. HIV patients with a CD4 count less than 200 cells/mm3 are more prone.
The clinical features of pneumonia caused by Pneumocystis jirovecii are:
Fever, chest pain, cough (usually non-productive), exertional dyspnoea, tachypnoea, crackles and wheeze.
Desaturation on exertion is a very sensitive sign of Pneumocystis jirovecii pneumonia.Chest X-ray can show perihilar fluffy shadowing (as is seen in this case) but can also be normal.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 9
Correct
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Which of the following laboratory findings are indicative of von Willebrand disease (VWD):
Your Answer: Prolonged APTT
Explanation:Laboratory results often show that:
PFA-100 test results are abnormal.
Low levels of factor VIII (if a factor VIII/VWF binding assay is conducted)
APTT is Prolonged (or normal)
PT is normal
VWF values are low.
Defective Platelet aggregation
The platelet count is normal. -
This question is part of the following fields:
- Haematology
- Pathology
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Question 10
Correct
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Which of the following is a contraindication to using nitrous oxide:
Your Answer: Raised intracranial pressure
Explanation:Nitrous oxide should not be utilized in patients with an air-containing confined area because it diffuses into these spaces, causing a rise in pressure. This includes circumstances like pneumothorax, intracranial air after a head injury, imprisoned air from a recent undersea dive, a recent intraocular gas injection, or intestinal blockage. Nitrous oxide increases cerebral blood flow and should be avoided in individuals who have or are at risk of having high intracranial pressure.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 11
Incorrect
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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: Lymphocytes
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.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 12
Correct
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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 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).
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 13
Correct
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Which patients are particularly susceptible to infection with herpes simplex, those with:
Your Answer: T-cell deficiency
Explanation:Cell-mediated immunity, especially the action of cytotoxic T-cells, is essential in the control of herpesvirus infections and patients with T-cell deficiency are at particular risk of reactivation and severe infection. T-cell deficiency may follow HIV infection, chemotherapy, corticosteroid therapy or organ transplantation.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 14
Incorrect
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Regarding Campylobacter gastroenteritis, which of the following statements is INCORRECT:
Your Answer: Bloody diarrhoea is a typical feature.
Correct Answer: Infection usually requires antibiotic treatment.
Explanation:Campylobacter jejuni is the primary human pathogen, typically causing dysentery (bloody diarrhoea illness) following ingestion of contaminated meat, especially poultry. Infection is typically self-limiting and does not require antibiotic therapy. Campylobacter gastroenteritis is associated with the immune-mediated complications of Guillain-Barre syndrome, reactive arthritis and Reiter’s syndrome.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 15
Correct
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Question 16
Incorrect
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A blood culture was performed from a sample taken from a patient. It was noted that a Gram-negative coccus organism was grown.
Among the following microorganisms, which is considered an example of a Gram-negative coccus?Your Answer: Escherichia coli
Correct Answer: Neisseria menigitidis
Explanation:Staphylococcus aureus = Gram-positive coccus
Bacillus cereus = Gram-positive bacillus
Campylobacter jejuni = Gram-negative bacillus
Escherichia coli = Gram-negative bacillusIn Gram staining, crystal violet is a purple stain that is used to stain the bacteria first. The stained bacteria are decolorized and then stained with a red stain, which is safranin. Bacteria with thick cell walls keep the purple stain and are called Gram-positive. Thin-walled bacteria are easily decolorized so when safranin, the red stain, is placed on the organisms, they become red or Gram-negative.
Neisseria species appear as Gram-negative diplococci because they form pairs and their adjacent ends are flattened that is why they are also described to have a coffee-bean or kidney-bean shape. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 17
Correct
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A 45-year-old obese patient goes to the emergency department with a fever and significant right upper quadrant pain. The pain radiates to her right shoulder tip. Murphy's sign is positive and acute cholecystitis is diagnosed. The pain referred to the shoulder tip is caused by one of the following nerves:
Your Answer: Phrenic nerve
Explanation:Gallbladder inflammation can cause pain in the right upper quadrant and right shoulder, which is caused by irritation of the diaphragmatic peritoneum. Pain from areas supplied by the phrenic nerve is often referred to other somatic regions served by spinal nerves C3-C5.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 18
Correct
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Regarding platelets, which of the following statements is CORRECT:
Your Answer: Platelets are produced in the bone marrow by fragmentation of the cytoplasm of megakaryocytes.
Explanation:Platelets are produced in the bone marrow by fragmentation of the cytoplasm of megakaryocytes, derived from the common myeloid progenitor cell. The time interval from differentiation of the human stem cell to the production of platelets averages 10 days. Thrombopoietin is the major regulator of platelet formation and 95% of this is produced by the liver. The normal platelet count is approximately 150 – 450 x 109/L and the normal platelet lifespan is 10 days. Under normal circumstances, about one-third of the marrow output of platelets may be trapped at any one time in the normal spleen.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 19
Correct
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A 32-year old male patient has been diagnosed with meningococcal meningitis and was given appropriate treatments. Because he is a family man, he fears that he might transmit the infection to the rest of his family members.
The causative agent of meningococcal meningitis is spread via what mode of transmission?Your Answer: Respiratory droplet route
Explanation:N. meningitidis, the causative agent of meningococcal meningitis, is considered both a commensal and a pathogen. It can be found in the surfaces of mucous membranes such as the nasopharynx and oropharynx. With this, it can be transmitted from a carrier to a new host via respiratory droplet secretions.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 20
Correct
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What is the recommended dosing regime for amiodarone in the treatment of a stable regular broad-complex tachycardia:
Your 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.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 21
Correct
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Which of the following drugs is first line treatment for a stable regular broad-complex tachycardia:
Your Answer: Amiodarone
Explanation:A regular broad-complex tachycardia is likely to be ventricular tachycardia or a regular supraventricular rhythm with bundle branch block. 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. If previously confirmed as SVT with bundle branch block, the patient should be treated as for narrow-complex tachycardia.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 22
Correct
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A 64-year-old woman had a humerus midshaft fracture due to tripping on a curb and falling on her left arm. She might also have damaged which of the following structures?
Your Answer: Radial nerve and deep brachial artery
Explanation:The radial nerve and brachial artery are most likely to be damaged in humerus fractures. They are tethered together to the bone and cannot withstand the forces applied to it as a result of the displacement.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 23
Correct
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A 42-year-old woman with a history of hyposplenism arrives at the Emergency Department sick and feverish. A complete set of bloods, including a peripheral blood film, is organised.
On a hyposplenic blood film, which of the following features is LEAST likely to be seen?Your Answer: Teardrop cells
Explanation:The collection of abnormalities found in these patients is referred to as a hyposplenic film.
The following features can be seen on hyposplenic blood films:
Howell-Jolly bodies
Heinz’s bodies
Target cells
RBCs with nuclei on occasion
Lymphocytosis
Macrocytosis
Acanthocytes
Teardrop cells, also known as dacrocytes, are named for their teardrop-shaped shape.Dacrocytosis is a condition in which a large number of these cells are present. Myelofibrosis and beta thalassemia major both have dacrocytes, but hyposplenism does not.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 24
Correct
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A 30-year-old woman presents with a history of fever and sore throat. On examination, there is tonsillar exudate and cervical lymphadenopathy and a diagnosis of tonsillitis is made. A course of penicillin is prescribed.
What is the mechanism of action of penicillin?
Your Answer: Inhibition of cell wall synthesis
Explanation:Penicillin is bactericidal and produces its antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. This action inhibits cell wall synthesis.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 25
Correct
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All of the following statements are correct regarding penicillin antibiotics except:
Your Answer: Penicillins are of no use in meningitis as they are unable to penetrate into the cerebrospinal fluid.
Explanation:Penicillin penetration into the cerebrospinal fluid is generally poor. However, when the meninges are inflamed, as in meningitis, penetration of penicillin is increased. Benzylpenicillin should be given before transfer to hospital if meningococcal disease (meningitis with non-blanching rash or meningococcal septicaemia) is suspected, once this does not delay transfer.
Benzylpenicillin is no longer the drug of first choice for pneumococcal meningitis.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 26
Correct
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Regarding thalassaemia, which of the following statements is CORRECT:
Your Answer: Screening for thalassaemia in pregnancy is offered to all pregnant women.
Explanation:Beta thalassemia is caused by mutations in one or both of the beta globin genes. Alpha thalassemia is caused by a deletion or mutation (less commonly) in one or more of the four alpha globin gene copies. β-thalassaemia is more common in the Mediterranean region while α-thalassaemia is more common in the Far East.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 27
Correct
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The pathophysiology of Addison's disease is as follows:
Your Answer: Adrenocortical insufficiency
Explanation:Primary adrenal insufficiency, also known as Addison’s disease, occurs when the adrenal glands cannot produce an adequate amount of hormones despite a normal or increased corticotropin (ACTH) level.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 28
Correct
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Which of the following could denote a diagnosis of acquired immunodeficiency syndrome (AIDS) in a patient infected with HIV:
Your Answer: CD4 count < 200 cells/uL
Explanation:A diagnosis of AIDS can be made in a patient infected with HIV if the patient has a CD4 count < 200 cells/uL, or an AIDS-defining illness. Antiretroviral treatment should be considered in patients with CD4 counts < 350 cells/uL.
Oral candidiasis is not an AIDS defining illness – candidiasis of the bronchi, trachea, lungs or of the oesophagus is an AIDS defining illness.
A positive p24 antigen test seen in early HIV infection and does not indicate the development of AIDS.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 29
Incorrect
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Which of the following antibiotics is the first line of treatment for a patient who has been diagnosed with chlamydia infection?
Your Answer: Ceftriaxone
Correct Answer: Azithromycin
Explanation:The Centres for Disease Control and Prevention (CDC) recommends azithromycin, a single 1 g dose, and doxycycline, 100 mg bd for 7 days, as first-line medications for chlamydial infection treatment.
Second-line medications (such as erythromycin, penicillins, and sulfamethoxazole) are less effective and have more side effects
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 30
Incorrect
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You examine a 78-year-old man who has been diagnosed with chronic lymphocytic leukaemia (CLL).
What is the MAIN contributory factor in this condition's immunodeficiency?Your Answer: Lymphopenia
Correct Answer: Hypogammaglobulinemia
Explanation:Immunodeficiency is present in all patients with chronic lymphocytic leukaemia (CLL), though it is often mild and not clinically significant. Infections are the leading cause of death in 25-50 percent of CLL patients, with respiratory tract, skin, and urinary tract infections being the most common.
Hypogammaglobulinemia is the most common cause of immunodeficiency in CLL patients, accounting for about 85 percent of all cases.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 31
Incorrect
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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
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Question 32
Incorrect
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In the Paediatric Emergency Department, you saw a 6-year-old girl with severe bilateral conjunctivitis. You give her mother some general eye hygiene advice and prescribe chloramphenicol eye drops.
What is the chloramphenicol's mechanism of action?
Your Answer: Disruption of cell membrane function
Correct Answer: Inhibition of protein synthesis
Explanation:Chloramphenicol is a broad-spectrum antibiotic that inhibits bacterial protein synthesis by blocking the 50S subunit of the bacterial ribosome’s peptidyl transferase activity. When administered systemically, it has limited usage due to the potential of significant side effects such as aplastic anaemia, peripheral neuropathy, and optic neuritis. It’s only used to treat typhoid fever and Haemophilus influenzae meningitis, but it’s usually better to use a broad-spectrum cephalosporin.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 33
Incorrect
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Platelet alpha granules release which of the following?
Your Answer: Thromboxane A2
Correct Answer: Von Willebrand factor (VWF)
Explanation:There are three types of storage granules contained in platelets. These are dense granules which contain the following:
-ATP
-ADP
-serotonin and calcium alpha granules containing clotting factors
-von Willebrand factor (VWF)
-platelet-derived growth factor (PDGF)
– other proteins lysosomes containing hydrolytic enzymes. -
This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 34
Correct
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In the emergency department, a 50-year-old female appears with a lack of sensation over the front two-thirds of her tongue. Taste and salivation are both present. The patient might have damage which of her nerves?
Your Answer: Lingual nerve
Explanation:The lingual nerve, a branch of the mandibular nerve, transmits sensation to the anterior two-thirds of the tongue.
The chorda tympani, a branch of the facial nerve, transmits taste to the front two-thirds of the tongue as well as secretomotor innervation to the submandibular and sublingual glands.
As a result, any damage to the lingual nerve can cause changes in salivary secretion on the affected side, as well as a loss of taste in the anterior two-thirds of the tongue and temporary or permanent sensory changes in the anterior two-thirds of the tongue and the floor of the mouth.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 35
Correct
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Following the administration of a medication for a heart condition, a 69-year-old man develops hypothyroidism.
Which of the following drugs is most likely to be the cause?Your Answer: Amiodarone
Explanation:Amiodarone has a chemical structure that is similar to that of thyroxine and can bind to the nuclear thyroid receptor. It can cause both hypothyroidism and hyperthyroidism, though hypothyroidism is far more common, with 5-10% of patients suffering from it.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 36
Incorrect
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Regarding oral rehydration therapy, which of the following statements is INCORRECT:
Your Answer: Oral rehydration solutions should contain an alkalinising agent to counter acidosis.
Correct Answer: Oral rehydration solutions should be slightly hyperosmolar.
Explanation:Oral rehydration therapy (ORT) is a fluid replacement strategy used to prevent or treat dehydration. It is less invasive than other strategies for fluid replacement and has successfully lowered the mortality rate of diarrhoea in developing countries. Oral rehydration solutions should be slightly hypo-osmolar (about 250 mmol/litre) to prevent the possible induction of osmotic diarrhoea.
ORT contains glucose (e.g. 90 mmol/L in dioralyte). The addition of glucose improves sodium and water absorption in the bowel and prevents hypoglycaemia. It also contains essential mineral salts.
Current NICE guidance recommends that 50 ml/kg is given over 4 hours for the treatment of mild dehydration.
Once rehydrated, a child should continue with their usual daily fluid intake plus 200 ml ORT after each loose stool. In an infant, give ORT at 1-1.5 x the normal feed volume and in an adult, give 200-400 ml after each loose stool. -
This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
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Question 37
Correct
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You plan to use plain 1% lidocaine for a ring block on a finger that needs suturing.
Which SINGLE statement regarding the use of 1% lidocaine, in this case, is true?Your Answer: Lidocaine works by blocking fast voltage-gated sodium channels
Explanation:Lidocaine is a tertiary amine that is primarily used as a local anaesthetic but can also be used intravenously in the treatment of ventricular dysrhythmias.
Lidocaine works as a local anaesthetic by diffusing in its uncharged base form through neural sheaths and the axonal membrane to the internal surface of the cell membrane sodium channels. Here it alters signal conduction by blocking the fast voltage-gated sodium channels. With sufficient blockage, the membrane of the postsynaptic neuron will not depolarise and will be unable to transmit an action potential, thereby preventing the transmission of pain signals.
Each 1 ml of plain 1% lidocaine solution contains 10 mg of lidocaine hydrochloride. The maximum safe dose of plain lidocaine is 3 mg/kg. When administered with adrenaline 1:200,000, the maximum safe dose is 7 mg/kg. Because of the risk of vasoconstriction and tissue necrosis, lidocaine should not be used in combination with adrenaline in extremities such as fingers, toes, and the nose.
The half-life of lidocaine is 1.5-2 hours. Its onset of action is rapid within a few minutes, and it has a duration of action of 30-60 minutes when used alone. Its duration of action is prolonged by co-administration with adrenaline (about 90 minutes).
Lidocaine tends to cause vasodilatation when used locally. This is believed to be due mainly to the inhibition of action potentials via sodium channel blocking in vasoconstrictor sympathetic nerves. -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 38
Correct
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Tiredness, night sweats, and easy bruising are symptoms of a 58-year-old woman. Splenomegaly is observed during the examination.
Which of the following diagnoses is the SINGLE MOST LIKELY?Your Answer: Chronic myeloid leukaemia (CML)
Explanation:CML is a myeloproliferative disorder characterised by an abnormal pluripotent haemopoietic stem cell. A cytogenetic abnormality known as the Philadelphia chromosome, which results from a reciprocal translocation between the long arms of chromosomes 9 and 22, causes more than 80% of cases of CML.
CML is a disease that develops slowly over several years. This is known as the ‘chronic stage.’ This stage is usually asymptomatic, and 90 percent of patients are diagnosed at this point, with the disease being discovered frequently as a result of a routine blood test. During this stage, the bone marrow contains less than 10% immature white cells (blasts).
When CML cells expand, symptoms typically begin to appear. The ‘accelerated stage’ is what it’s called. Approximately 10% of people are diagnosed at this point. During this stage, between 10% and 30% of blood cells in the bone marrow are blasts. During this stage, common clinical features include:
Fatigue and exhaustion
Night sweats and fever
Distension of the abdomen
Pain in the left upper quadrant (splenic infarction)
Splenomegaly (commonest examination finding)
Hepatomegaly
Bruising is simple.
Gout is a type of arthritis that affects (rapid cell turnover)
Hyperviscosity is a condition in which the viscosity of (CVA, priapism)
A small percentage of patients experience a ‘blast crisis’ (blast stage). More than 30% of the blood cells in the bone marrow are immature blast cells at this stage. Patients with severe constitutional symptoms (fever, weight loss, bone pain), infections, and bleeding diathesis typically present at this stage.In CML, laboratory findings include:
White cell count is abnormally high (often greater than 100 x 109/l).
Increased number of immature leukocytes causes a left shift.
Anaemia that is mild to moderately normochromic and normocytic.
Platelets can be low, normal, or elevated, and the Philadelphia chromosome can be found in > 80% of patients.
Serum uric acid and ALP levels are frequently elevated.
Tyrosine kinase inhibitors (TKIs), such as imatinib and dasatinib, are the current mainstay of CML treatment.
Allogenic bone marrow transplantation is now only used in cases where TKIs have failed to work. -
This question is part of the following fields:
- Haematology
- Pathology
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Question 39
Correct
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A 34-year-old male is brought into the Emergency Department by the paramedics after a road traffic accident. After a quick triage, you establish that he will need to be intubated, and you ask for some ketamine to be prepared.
Which one of the following options regarding this drug is true?Your Answer: It is the only anaesthetic agent available that has analgesic, hypnotic, and amnesic properties
Explanation:Ketamine is a dissociative anaesthetic with analgesic, amnesic, and hypnotic effects. It is the only anaesthetic agent which causes all three of these effects.
Ketamine exerts its action by non-competitive antagonism at the NMDA (N-methyl-D-aspartate) receptor. Due to its analgesic property, Ketamine is given so that patients do not retain memories of short term procedures. Ketamine is used for the induction and maintenance of anaesthesia in general surgery and for treating burn wounds, battlefield injuries, and children who cannot tolerate other anaesthetic or analgesic agents.
It can be given by both intravenous and intramuscular routes. Ketamine causes cardiac stimulation by increasing the sympathetic tone. The major side effect is increased intracranial pressure as an increase in the sympathetic tone causes vasoconstriction and an increase in the MAP.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 40
Correct
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Diabetic ketoacidosis is characterised by which of the following:
Your Answer: Hyperglycaemia, ketonaemia and acidosis
Explanation:DKA is characterised by the biochemical triad:
1. Hyperglycaemia (> 11 mmol/L)
2. Ketonaemia (> 3 mmol/L)
3. Acidosis (pH < 7.3 +/- HCO3 < 15 mmol/L) -
This question is part of the following fields:
- Endocrine
- Physiology
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Question 41
Correct
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Which of the following best describes the correct administration of adrenaline for a shockable rhythm in adult advanced life support?
Your Answer: Give 1 mg of adrenaline after the second shock and every 3 - 5 minutes thereafter
Explanation:Give adrenaline 1 mg IV (IO) (10 mL of 1:10,000 solution) after the 2nd shock for adult patients in cardiac arrest with a shockable rhythm. Repeat adrenaline 1 mg IV (IO) every 3-5 minutes whilst ALS continues.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 42
Incorrect
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Insulin binds to the insulin receptor (IR) on cell surfaces to exert its action. The IR is a very specific transmembrane receptor belonging to the tyrosine kinase receptor class.
One of these also activates the IR:
Your Answer: Somatostatin
Correct Answer: IGF-I
Explanation:Insulin receptor (IR), in addition to being activated by insulin, is also activated by IGF-I and IGF-II.
The IR is a dimer with two identical subunits spanning the cell membrane and are connected by a single disulphide bond. The two sub-units include: The alpha chain situated on the exterior of the cell membrane and the beta chain spanning the cell membrane in a single segment.
When insulin is detected, the alpha chains move together folding around the insulin making the beta chains move together, converting them into an active tyrosine kinase. This initiates a phosphorylation cascade increasing the expression of GLUT4 and allowing uptake of glucose by cells.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 43
Correct
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The enzyme protein gastric lipase is responsible for the breakdown of lipids in the stomach.
Which of the following cell types secretes gastric lipase?Your Answer: Chief cells
Explanation:Gastric lipase, commonly known as LIPF, is an acidic lipase released by gastric chief cells, which are found deep within the stomach lining’s mucosal layer. It’s an enzymatic protein that’s in charge of fat digestion in the stomach.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 44
Incorrect
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A 26-year-old athlete presents with buttock pain after tearing his gluteus maximus muscle.
Which of the following is NOT an action of the gluteus maximus muscle? Select ONE answer only.Your Answer: Steadying of the thigh
Correct Answer: Hip abduction
Explanation:Gluteus maximus is the main extensor muscle of the hip and assists with lateral rotation of the thigh at the hip joint. It also acts as a hip adductor, steadies the thigh, and assists in raising the trunk from a flexed position.
Gluteus maximus is innervated by the inferior gluteal nerve. -
This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 45
Correct
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A patient suffers a stab wound to the neck. The entry point of the blade is situated within the anterior triangle of the neck.
Which of the following muscles is most likely to be involved? Select ONE answer only.Your Answer: 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
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Question 46
Correct
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A 62-year-old woman presents with cold sensitivity, tiredness, and weight gain. A series of blood tests done shows a grossly elevated TSH level and a diagnosis of hypothyroidism is made.
What is the commonest cause of hypothyroidism worldwide?Your Answer: Iodine deficiency
Explanation:Hypothyroidism occurs when there is a deficiency of circulating thyroid hormones. It is commoner in women and is most frequently seen in the age over 60.
Iodine deficiency is the commonest cause of hypothyroidism worldwide.
In developed countries, iodine deficiency is not a problem and autoimmune thyroiditis is the commonest cause.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 47
Correct
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Regarding acute idiopathic thrombocytopaenic purpura (ITP), which of the following statements is CORRECT:
Your Answer: Over 80% of children recover without treatment.
Explanation:Acute ITP is most common in children. In approximately 75% of cases, the episode follows vaccination or infection such as chicken pox or glandular fever. Most cases are caused by non-specific immune complex attachment to platelets. Acute ITP usually has a very sudden onset and the symptoms usually disappear in less than 6 months (often within a few weeks). It is usually a self-limiting condition and over 80% of children recover without treatment; in 5 – 10% of cases a chronic form of the disease develops.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 48
Correct
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After collapsing at home, a 75-year-old man is transported in an ambulance. He is now awake, but he is experiencing palpitations and chest pain. He is transported to resuscitation and placed on a cardiac monitor, which indicates that he is in VT. An amiodarone infusion is set up.
Which of the following statements about amiodarone side effects is correct?Your Answer: It can cause jaundice
Explanation:Amiodarone has a lot of potential toxic side effects, so it’s important to get a full clinical evaluation before starting treatment with it.
The following are some of the most common amiodarone side effects:
Arrhythmias
Corneal microdeposits
Hepatic disorders
Hyperthyroidism
Hypothyroidism
Hepatic disorders and jaundice
Nausea
Peripheral neuropathy
Respiratory disorders (including lung fibrosis)
Sleep disturbance
Skin reactions
QT prolongationAmiodarone can cause optic neuritis, which is a very rare side effect. If this happens, the amiodarone should be stopped right away because it poses a risk of blindness.
Most people who take amiodarone develop corneal microdeposits, which go away once the medication is stopped and rarely cause vision problems.
Amiodarone has a chemical structure that is similar to that of thyroxine and can bind to the nuclear thyroid receptor. It can cause both hypothyroidism and hyperthyroidism, though hypothyroidism is far more common, with 5-10% of patients suffering from it.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 49
Incorrect
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The percentage of patients with hepatitis B that develop chronic infection is about:
Your Answer: 2%
Correct Answer: 10%
Explanation:With hepatitis B, about 90% of people will develop lifelong immunity after clearing the infection. Chronic hepatitis develops in about 10% of patients and this may be complicated by cirrhosis or hepatocellular carcinoma. There is a very high risk of chronic infection and hepatocellular carcinoma when there is congenital infection. The risk of this in healthy adults is only about 5%.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 50
Incorrect
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A 30-year-old man presents with diarrhoea, fever, vomiting, and abdominal cramps. A stool culture was ordered and showed growth of Salmonella spp.
Among the following serotypes of Salmonella spp., which is considered to be the most common cause of salmonella gastroenteritis?Your Answer: Serotype A
Correct Answer: Serotype D
Explanation:A common cause of gastroenteritis, Salmonella enteritidis, and Salmonella typhi, which causes enteric fever, are both group D. Therefore, serotype D Salmonella species are most commonly associated with gastroenteritis.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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SESSION STATS - PERFORMANCE PER SPECIALTY
