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Question 1
Incorrect
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A 45-year old lady underwent biopsy of a soft, fleshy mass involving her left breast. The biopsy showed lymphoid stroma with minimal fibrosis, surrounding sheets of large vesicular cells with frequent mitoses. Which condition is she most likely suffering from?
Your Answer: Paget’s disease of the breast
Correct Answer: Medullary carcinoma of breast
Explanation:Medullary carcinoma is a malignant tumour of the breast with well-defined boundaries and accounts for 5% of all breast cancers. Other special features include a larger size of the neoplastic cells and presence of lymphoid cells at tumour edge. Differential diagnosis includes invasive ductal carcinoma. Prognosis is usually good.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 2
Incorrect
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If a 55-year old gentleman who has suffered a stroke, develops a tremor in his fingers that worsens on reaching for an object, what part of his brain is likely to be involved?
Your Answer: Basal ganglia
Correct Answer: Cerebellum
Explanation:The cerebellum plays an important role in the integration of sensory perception and motor output. Multiple neural pathways link the cerebellum with the motor cortex and the spinocerebellar tract. The cerebellum uses the constant feedback on body position to fine-tune the movements and integrates these pathways. The patient described here has a characteristic cerebellar tremor that is a slow, broad tremor of the extremities and occurs at the end of a purposeful movement.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 3
Incorrect
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During an appendicectomy in a 16 year old girl, the registrar initially did not find the appendix on entering the peritoneal cavity. She, however, remained calm as she knew she could find it by:
Your Answer: Palpating the ileocaecal valve and looking just above it
Correct Answer: Looking at the confluence of the taenia coli
Explanation:The vermiform appendix arises from the apex of the caecum. Although it has a constant base, it can pass in one of several directions such as upward behind the caecum, to the left behind the ileum and mesentery or downward into the lesser pelvis. It is retained in place by a peritoneal fold, the mesoenteriole derived from the left leaf of the mesentery. Taenia coli meet at the appendix which is the terminal portion of the caecum. The appendix is below the ileocecal valve, not above. It is not near the right colic artery (which supplies the ascending colon). It would not be found by removing a layer of the jejuno-ileum and is not in the pelvic brim.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 4
Incorrect
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A 45-year old male, who was a chronic smoker presented to the clinic with backache and dry, incessant cough. On examination, he was found to have raised blood pressure, purplish striae on his abdomen, truncal obesity and tenderness over the lower thoracic spine. These findings are suggestive of which condition?
Your Answer: Multiple endocrine neoplasia, type I
Correct Answer: Small-cell anaplastic (oat cell) carcinoma
Explanation:The symptoms suggest Cushing syndrome due to increased glucocorticoid levels. One cause of Cushing syndrome is ectopic production of adrenocorticotrophic hormone from oat cell carcinoma. As oat cell carcinoma is known to be highly metastatic, the tenderness in lower back could represent metastatic involvement.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 5
Correct
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An 80 year-old quadriplegic man has been lying supine for 7 weeks in a critical care ward. He develops a right lung abscess that is draining by gravity to a particular region of the lung. Which is the most likely site of pus collection?
Your Answer: Superior segment of the lower lobe
Explanation:The superior segmental bronchus of the lower lobe of the right lung branches posteriorly off the intermediate bronchus or the inferior lobe bronchus. It is therefore more likely to receive fluid or foreign bodies that enter the right main bronchus especially when the patient is supine.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 6
Correct
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What is the chief ligament preventing posterior sliding of the tibia on the femur ?
Your Answer: Posterior cruciate
Explanation:The posterior cruciate ligament is attached to the posterior intercondyloid fossa of the tibia and the lateral and front part of the medial condyle of the femur. It resists sliding of the tibia posteriorly.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 7
Correct
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The fundus of the stomach receives blood supply from the same artery as the greater curvature of the stomach. Which of the following arteries when ligated will disrupt blood supply to the fundus of the stomach through this artery?
Your Answer: Splenic
Explanation:The fundus of the stomach along with the greater curvature of the stomach receive blood supply from the short gastric artery. The short gastric artery arises from the end of the splenic artery. The ligation of the splenic artery therefore would cause a disruption of blood supply to the fundus of the stomach.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 8
Correct
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The Brunner glands secrete an alkaline product that helps maintain an optimal pH for pancreatic enzyme activity. Where are these glands located?
Your Answer: Submucosa of the duodeneum
Explanation:The Brunner glands are located in the submucosa of the duodenum. These glands are connected to the interstitial lumen by ducts that open into certain crypts. They secrete an alkaline product that protects the duodenal mucosa from the acidic chyme and helps achieve an optimal pH for the enzymes.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 9
Correct
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Regarding the posterior compartment of the leg, which is correct?
Your Answer: The muscles plantarflex the foot and are innervated by the tibial nerve
Explanation:The muscles of the back of the leg are subdivided into two groups: superficial and deep. Superficial muscles include gastrocnemius, soleus and plantaris. Deep muscles include tibialis posterior, flexor hallucis longus, flexor digitorum longus and popliteus. The superficial ( calf muscles) which are responsible for plantarflexion of the foot are supplied by the tibial nerve as follows: the gastrocnemius and soleus muscles are supplied by the first and second sacral nerves and the plantaris by the fourth and fifth lumbar and first sacral nerve (the tibial nerve).
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 10
Correct
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A 15-day old male baby was brought to the emergency department with sweating and his lips turning blue while feeding. He was born full term. On examination, his temperature was 37.9°C, blood pressure 75/45 mmHg, pulse was 175/min, and respiratory rate was 42/min. A harsh systolic ejection murmur could be heard at the left upper sternal border. X-ray chest showed small, boot-shaped heart with decreased pulmonary vascular markings. He most likely has:
Your Answer: Tetralogy of Fallot
Explanation:The most common congenital cyanotic heart disease and the most common cause of blue baby syndrome, Tetralogy of Fallot shows four cardiac malformations occurring together. These are ventricular septal defect (VSD), pulmonary stenosis (right ventricular outflow obstruction), overriding aorta (degree of which is variable), and right ventricular hypertrophy. The primary determinant of severity of disease is the degree of pulmonary stenosis. Tetralogy of Fallot is seen in 3-6 per 10,000 births and is responsible for 5-7% congenital heart defects, with slightly higher incidence in males. It has also been associated with chromosome 22 deletions and DiGeorge syndrome. It gives rise to right-to-left shunt leading to poor oxygenation of blood. Primary symptom is low oxygen saturation in the blood with or without cyanosis at birth of within first year of life. Affected children ay develop acute severe cyanosis or ‘tet spells’ (sudden, marked increase in cyanosis, with syncope, and may result in hypoxic brain injury and death). Other symptoms include heart murmur, failure to gain weight, poor development, clubbing, dyspnoea on exertion and polycythaemia. Chest X-ray reveals characteristic coeur-en-sabot (boot-shaped) appearance of the heart. Treatment consists of immediate care for cyanotic spells and Blalock–Taussig shunt (BT shunt) followed by corrective surgery.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 11
Correct
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A 30-year old lady presented to her GP with complaints of tremors, excessive emotional outbursts, weight loss and increased sweating over 20 days. On examination, she had warm and moist skin, a fine tremor of the fingers and hyperreflexia. Her vital signs were normal. What is the likely diagnosis?
Your Answer: Hyperthyroidism
Explanation:Excess of circulating free thyroid hormones (thyroxine and/or triiodothyronine) leads to hyperthyroidism. Common causes include Graves’ disease, toxic thyroid adenoma and toxic multinodular goitre. Grave’s disease is the most common cause and is responsible for 70-80% cases of hyperthyroidism. Other causes include excess intake of thyroid hormone, amiodarone-related. It is important that hyperthyroidism is not confused with hyperthyroxinaemia (high levels of thyroid hormone in blood), which includes causes like thyroiditis. Both the conditions lead to thyrotoxicosis (symptoms due to hyperthyroxinemia). Symptoms include weight loss associated with increased appetite, anxiety, weakness, heat intolerance, depression, increased sweating, dyspnoea, loss of libido, diarrhoea, palpitations and occasionally arrhythmias. If there is an acute increase in metabolic rate, the condition is known as ‘thyroid storm’. Elderly sometimes present only with fatigue and weight loss and this is called apathetic hyperthyroidism. Neurological symptoms are also seen in hyperthyroidism and these are tremor, chorea, myopathy and periodic paralysis. One of the most serious complications of hyperthyroidism is stroke of cardioembolic origin due to coexisting atrial fibrillation.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 12
Incorrect
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Urine specific gravity allows the assessment of which of the following renal functions?
Your Answer: Filtration
Correct Answer: Concentration
Explanation:Concentrating ability of kidneys is assessed by measuring the urine specific gravity. Normal values of urine specific gravity fall between 1.002 and 1.030 g/ml.
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This question is part of the following fields:
- Pathology
- Renal
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Question 13
Incorrect
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Which of the following muscles is innervated by the inferior branch of the right recurrent laryngeal nerve?
Your Answer: Lateral cricoarytenoid
Correct Answer: Posterior cricoarytenoid
Explanation:The posterior cricoarytenoid muscle, which is the sole abductor of the vocal folds, receives its innervation from the inferior laryngeal nerve which is a continuation of the recurrent laryngeal nerve.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 14
Correct
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Out of the following options, which malignancy has the highest potential for multicentricity?
Your Answer: Transitional cell carcinoma
Explanation:Transitional cell carcinomas can arise anywhere in the urothelium lining the urinary tract; and hence are known to be multicentric and recur commonly. Prostatic adenocarcinoma most commonly involves the posterior lobe of the prostate gland. Although renal cell carcinomas occasionally show multicentricity, it is not common. Penile carcinomas are usually locally infiltrative lesions. Wilm’s tumours are usually solitary, but can be bilateral or multicentric in 10% cases. Small cell carcinoma of lung and teratomas are usually solitary.
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This question is part of the following fields:
- Pathology
- Renal
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Question 15
Correct
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Congenital anomalies of genitourinary tract are more common than any other system. Which of the following anomalies carries the greatest risk of morbidity?
Your Answer: Bladder exstrophy
Explanation:Bladder exstrophy is the condition where the urinary bladder opens from the anterior aspect suprapubically. The mucosa of the bladder is continuous with the abdominal skin and there is separation of the pubic bones. The function of the upper urinary tract remains normal usually. Treatment consists of surgical reconstruction of the bladder and returning it to the pelvis. There can be a need for continent urinary diversion along with reconstruction of the genitals.
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This question is part of the following fields:
- Pathology
- Renal
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Question 16
Incorrect
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If your EEG shows waves with a frequency range of 8-12 Hz, the waves most likely to be seen are:
Your Answer: Gamma
Correct Answer: Alpha
Explanation:Electroencephalography (EEG) is the neurophysiological measurement of the electrical activity of the brain. It is done by placing electrodes on the scalp or subdurally. In reality, the electrical currents are not measured, but rather the voltage differences between different parts of the brain. Four major types of EEG activity are recognized, which are alpha, beta, delta and theta.
Alpha waves, also known as Berger’s waves ranges in frequency from 8-12 Hz. Best detected with eyes closed, alpha waves are characteristic of a relaxed, alert state of consciousness. An alpha-like normal variant called mu is sometimes seen over the motor cortex (central scalp) and attenuates with movement or, rather, with the intention to move.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 17
Incorrect
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A 30-year-old woman feels thirsty. This thirst is probably due to:
Your Answer: Hypokalaemia
Correct Answer: Increased level of angiotensin II
Explanation:Thirst is the basic need or instinct to drink. It arises from a lack of fluids and/or an increase in the concentration of certain osmolites such as salt. If the water volume of the body falls below a certain threshold or the osmolite concentration becomes too high, the brain signals thirst. Excessive thirst, known as polydipsia, along with excessive urination, known as polyuria, may be an indication of diabetes. Angiotensin II is a hormone that is a powerful dipsogen (i.e. it stimulates thirst) that acts via the subfornical organ. It increases secretion of ADH in the posterior pituitary and secretion of ACTH in the anterior pituitary.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 18
Correct
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After total thyroidectomy, which of the following investigations is recommended in the immediate post-operative period?
Your Answer: Serum calcium
Explanation:Total thyroidectomy might sometimes result in inadvertent excision or damage of parathyroid glands, leading to hypoparathyroidism. Monitoring serum calcium levels in the post-operative period to detect hypocalcaemia is essential to diagnose and prevent this condition.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 19
Incorrect
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Which of the following is the most likely cause of prolonged thrombin clotting time?
Your Answer: Warfarin therapy
Correct Answer: Hypofibrinogenemia
Explanation:Thrombin clotting time, also called thrombin time (TT), is test used for the investigation of possible bleeding or clotting disorders. TT reflects the conversion of fibrinogen to fibrin and it’s also very sensitive to the presence of the anticoagulant heparin. A prolonged thrombin time may indicate the presence of hypofibrinogenemia (decreased fibrinogen level ), dysfibrinogenaemia, disseminated intravascular coagulation (DIC), end stage liver disease or malnutrition.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 20
Correct
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A 15-year-old girl was diagnosed with bacterial meningitis. Gram staining of the spinal fluid shows numerous polymorphonuclear neutrophils and Gram-positive cocci. Which is the empiric drug of choice to be given to the patient until the antibiotic sensitivity report is available?
Your Answer: Ceftriaxone
Explanation:Acute meningitis is a medical emergency. All suspects should receive their first dose of antibiotics immediately and be transferred to hospital as soon as possible. If facilities for blood culture and/or lumbar puncture (LP) are immediately available, they should be performed before administration
of the first dose of antibiotics (see contraindications to LP below). Neither procedure should lead to a significant delay in antibiotic administration.
Administer ceftriaxone 80-100 mg/kg (maximum 2 g, 12 hourly) intravenously. The intramuscular or intraosseous route can be used if there is no vascular access. Penicillin allergy is not a contraindication to ceftriaxone in acute meningitis (C-1). Omit ceftriaxone only if there has been documented ceftriaxone anaphylaxis. Give chloramphenicol 25 mg/kg (maximum 500 mg) intravenously instead, if available. Administer adequate analgesia and transfer the patient immediately to hospital, detailing all administered
medication in the referral letter. -
This question is part of the following fields:
- Microbiology
- Pathology
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Question 21
Correct
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From which fascia of the pelvic wall muscle does the levator ani muscle arise?
Your Answer: Obturator internus
Explanation:The levator ani muscle arises from the posterior surface of the superior ramus of the pubis lateral to the symphysis, behind the inner surface of the spine of the ischium and between these points from the obturator internus fascia. It is attached to the inner surface of the side of the lesser pelvic cavity, supports the viscera in the cavity and surrounds the various structures that pass through it.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 22
Correct
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An X ray of a 60 year old male brought to the accident and emergency following a fall down stairs shows a fractured olecranon process of the right ulna with the line of fracture passing through the superior surface, disrupting a muscle. Which among the following muscles was most likely injured?
Your Answer: Triceps brachii
Explanation:The superior surface of the olecranon process forms an attachment for the insertion of the triceps brachii on the posterior aspect. It also has a minor transverse groove for the attachment of part of the posterior ligament of the elbow on the anterior aspect.
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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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Which of the following conditions may cause hypervolaemic hyponatraemia?
Your Answer: Cirrhosis
Explanation:Hypovolaemic hyponatraemia: reduced extracellular fluid
Renal loss of sodium and water; urine Na >20 mmol/day
Causes:
Diuretic use
Salt wasting nephropathy
Cerebral salt wasting
Mineralocorticoid deficiency/adrenal insufficiency
Renal tubular acidosis
Extrarenal loss of sodium and water with renal conservation; urine Na <20 mmol/day
Causes:
Burns
Gastrointestinal loss
Pancreatitis
Blood loss
3rd space loss (bowel obstruction, peritonitis)Hypervolaemic hyponatraemia: expanded intracellular fluid and extracellular fluid but reduced effective arterial blood volume
Causes:
Congestive cardiac failure
Cirrhosis
Nephrotic syndromeEuvolaemic hyponatraemia: expanded intracellular and extracellular fluid but oedema absent
Causes:
Thiazide diuretics (can be euvolaemic or hypovolaemic)
Hypothyroidism
Adrenal insufficiency (can be euvolaemic or hypovolaemic)
SIADH (cancer, central nervous system disorders, drugs, pulmonary disease, nausea, postoperative pain, HIV, infection, Guillain‐Barre syndrome, acute intermittent porphyria)
Decreased solute ingestion (beer potomania/tea and toast diet) -
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 24
Correct
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After a cerebral infarction, which of these histopathogical findings is most likely to be found?
Your Answer: Liquefactive necrosis
Explanation:The brain has a high lipid content and typically undergoes liquefaction with ischaemic injury, because it contains little connective tissue but high amounts of digestive enzymes.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 25
Incorrect
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A 72-year-old male presents with dysuria and chronic haematuria. He was diagnosed with bladder cancer and tumour invasion of the perivesical fat. What is the stage of the patient's bladder cancer?
Your Answer: T4
Correct Answer: T3
Explanation:Bladder cancer is the growth of abnormal or cancerous cells on the inner lining of the bladder wall. The staging is as follows; stage 0is (Tis, N0, M0): Cancerous cells in the inner lining tissue of the bladder only, stage I (T1, N0, M0): tumour has spread onto the bladder wall, stage II (T2, N0, M0): tumour has penetrated the inner wall and is present in muscle of the bladder wall, stage III (T3, N0, M0): tumour has spread through the bladder to fat around the bladder and stage IV: (T4, N0, M0): tumour has grown through the bladder wall and into the pelvic or abdominal wall. The stage of cancer in the case presented is T3 because of the invasion of perivesical fat.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 26
Correct
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What percentage of the cardiac output is delivered to the brain?
Your Answer: 15%
Explanation:Among all body organs, the brain is most susceptible to ischaemia. Comprising of only 2.5% of total body weight, the brain receives 15% of the cardiac output. Oxygen extraction is also higher with venous oxygen levels approximating 13 vol%, and arteriovenous oxygen difference of 7 vol%.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 27
Incorrect
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A 70-year-old man who was previously healthy develops a rapidly progressing neurological deficit. A MRI reveals a large, poorly defined mass with central necrosis in his left temporal lobe. What is the most likely diagnosis?
Your Answer: Meningioma
Correct Answer: Glioblastoma multiforme
Explanation:Glioblastoma multiforme, or grade 4 astrocytoma, is the most common and aggressive primary brain tumour. They are formed by small areas of necrotising tissue surrounded by highly anaplastic cells. Most of them arise from the deep white matter of the brain and quickly infiltrate it, becoming very large before they are symptomatic. The most common symptom is progressive memory, personality or neurological deficit due to temporal and frontal lobe involvement. It is most common in men, and risk factors include: neurofibromatosis, tuberous sclerosis, Von Hippel-Lindau disease, Li-Fraumeni syndrome, and Turcot syndrome.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 28
Correct
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A 70-year-old man suffers an ischaemic stroke and develops a left homonymous hemianopia. Where is the likely infarct?
Your Answer: Right occipital lobe
Explanation:The man has a left homonymous hemianopia which means he is unable to view objects in the left visual field. This information is processed by the right primary visual cortex which lies in the right occipital lobe.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 29
Incorrect
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Which of the following will increase blood pressure and cause hypokalaemia?
Your Answer: Desmopressin
Correct Answer: Angiotensin II
Explanation:Angiotensin is a peptide that is released in response to a decrease in blood volume and blood pressure. It has multiple functions but mainly acts to cause vasoconstriction, increase BP and release aldosterone from the adrenal cortex. It is a powerful vasoconstrictor and release of aldosterone causes increased retention of sodium and excretion of potassium.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 30
Incorrect
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Injury to the supraspinatus muscle will affect:
Your Answer: Lateral rotation of the humerus
Correct Answer: Initiation of abduction of the humerus
Explanation:This muscle arises from the medial two-thirds of the supraspinatus fossa and from the supraspinatus fascia. It is inserted into the highest impression on the greater tubercle of the humerus after passing over the upper part of the shoulder joint. It works with the deltoid to raise the arm from the side of the trunk and initiate abduction. It also assists in fixation of the head of the humerus in the glenoid cavity.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 31
Incorrect
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A CT-scan report of a patient with gastric carcinoma shows that the lymph nodes around the coeliac trunk are enlarged. The coeliac trunk:
Your Answer: Is surrounded by the aorticorenal ganglion
Correct Answer: Gives rise to the splenic, left gastric and common hepatic arteries
Explanation:The coeliac trunk is a branch of the aorta arising just below the aortic hiatus of the diaphragm to pass nearly horizontally forward to divide into 3 large branches i.e. the left gastric, the hepatic and the splenic arteries. Occasionally it may give off one of the inferior phrenic arteries. It is covered by the lesser omentum and on the right side bordered by the right coeliac ganglion and the cardiac end of the stomach. Inferiorly it is bordered by the upper border of the pancreas and splenic vein. The embryonic midgut is supplied by the superior mesenteric artery.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 32
Incorrect
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A 48-year-old woman has a mass in her right breast and has right axillary node involvement. She underwent radical mastectomy of her right breast. The histopathology report described the tumour to be 4 cm in its maximum diameter with 3 axillary lymph nodes with evidence of tumour. The most likely stage of cancer in this patient is:
Your Answer: IIIB
Correct Answer: IIB
Explanation:Stage IIB describes invasive breast cancer in which: the tumour is larger than 2 centimetres but no larger than 5 centimetres; small groups of breast cancer cells — larger than 0.2 millimetre but not larger than 2 millimetres — are found in the lymph nodes OR the tumour is larger than 2 centimetres but no larger than 5 centimetres; cancer has spread to 1 to 3 axillary lymph nodes or to lymph nodes near the breastbone (found during a sentinel node biopsy) OR the tumour is larger than 5 centimetres but has not spread to the axillary lymph nodes.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 33
Incorrect
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A child defecates a few minutes after being fed by the mother. This is most likely due to:
Your Answer: Vasovagal reflex
Correct Answer: Gastrocolic reflex
Explanation:The gastrocolic reflex is a physiological reflex that involves increase in colonic motility in response to stretch in the stomach and by-products of digestion in the small intestine. It is shown to be uneven in its distribution throughout the colon, with the sigmoid colon affected more than the right side of the colon in terms of a phasic response. Various neuropeptides have been proposed as mediators of this reflex, such as serotonin, neurotensin, cholecystokinin and gastrin.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 34
Correct
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A 25-year-old female had a painful abdomen and several episodes of vomiting. She was severely dehydrated when she was brought to the hospital. Her ABG showed a pH 7.7, p(O2) 75 mmHg, p(CO2) 46 mmHg and bicarbonate 48 mmol/l. The most likely interpretation of this ABG report would be:
Your Answer: Metabolic alkalosis
Explanation:Metabolic alkalosis is a primary increase in bicarbonate (HCO3−) with or without compensatory increase in carbon dioxide partial pressure (Pco2); pH may be high or nearly normal. Metabolic alkalosis occurs as a consequence of a loss of H+ from the body or a gain in HCO3 -. In its pure form, it manifests as alkalemia (pH >7.40). As a compensatory mechanism, metabolic alkalosis leads to alveolar hypoventilation with a rise in arterial carbon dioxide tension p(CO2), which diminishes the change in pH that would otherwise occur. Normally, arterial p(CO2) increases by 0.5–0.7 mmHg for every 1 mmol/l increase in plasma bicarbonate concentration, a compensatory response that occurs very rapidly. If the change in p(CO2) is not within this range, then a mixed acid–base disturbance occurs. Likewise, if the increase in p(CO2) is less than the expected change, then a primary respiratory alkalosis is also present. However an elevated serum bicarbonate concentration can also occur due to a compensatory response to primary respiratory acidosis. A bicarbonate concentration greater than 35 mmol/l is almost always caused by metabolic alkalosis (as is the case in this clinical scenario). Calculation of the serum anion gap can also help to differentiate between primary metabolic alkalosis and the metabolic compensation for respiratory acidosis. The anion gap is frequently elevated to a modest degree in metabolic alkalosis because of the increase in the negative charge of albumin and the enhanced production of lactate. However, the only definitive way to diagnose metabolic alkalosis is by performing a simultaneous blood gases analysis, which reveals elevation of both pH and arterial p(CO2) and increased calculated bicarbonate.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 35
Correct
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A 5 year-old-child with fever complains of sore throat . She was brought to her paediatrician for consult because she has also developed a rash and has swollen lymph nodes. Upon physical examination she cried when her liver was palpated and the tip of her spleen is slightly palpable. Full blood count shows haemoglobin 13 g/dL, Haematocrit 40%, white blood cell count 13x109/L with a WBC differential count of 45 neutrophils, 4 bands, 26 lymphocytes, 15 atypical lymphocytesm, 10 monocytes and 1 eosinophil. Whick is the most likely infectious agent that is responsible for the patient's condition?
Your Answer: Epstein–Barr virus
Explanation:Epstein-Barr virus (EBV), also known as human herpes virus 4,is a member of the herpes virus family. EBV spreads most commonly through bodily fluids, primarily saliva. EBV can cause infectious mononucleosis. Symptoms of EBV can include fatigue, fever, inflamed throat, swollen lymph nodes in the neck, enlarged spleen, swollen liver and rash.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 36
Correct
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Question 37
Correct
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Question 38
Correct
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In a young, sexually active male, what is the most common cause of non-gonococcal urethritis?
Your Answer: Chlamydia
Explanation:Non-gonococcal urethritis is most commonly caused by Chlamydia trachomatis (50% cases). Less common organisms include Mycoplasma genitalium, Urea urealyticum and Trichomonas vaginalis. Chlamydia is also the commonest cause of non-gonococcal cervicitis in women and proctitis in both sexes.
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This question is part of the following fields:
- Pathology
- Renal
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Question 39
Incorrect
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A 76-year-old woman is diagnosed with diabetes mellitus after a urine test revealed she has glucosuria. Glucosuria may occur due to inadequate glucose reabsorption at:
Your Answer: Collecting duct
Correct Answer: Proximal convoluted tubule
Explanation:Glucose is reabsorbed almost 100% via sodium–glucose transport proteins (apical) and GLUT (basolateral) in the proximal convoluted tubule. Glycosuria or glucosuria is a condition of osmotic diuresis typical in those suffering from diabetes mellitus. Due to a lack of insulin, plasma glucose levels are above normal. This leads to saturation of receptors in the kidneys and glycosuria usually at plasma glucose levels above 11 mmol/l. Rarely, glycosuria is due to an intrinsic problem with glucose reabsorption within the kidneys (such as Fanconi syndrome), producing a condition termed renal glycosuria.
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This question is part of the following fields:
- Physiology
- Renal
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Question 40
Incorrect
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Choose the most correct answer regarding the obturator internus muscle.
Your Answer: It emerges from the pelvis through the greater sciatic foramen
Correct Answer: It emerges from the pelvis through the lesser sciatic foramen
Explanation:The obturator internus arises from the inner surface of the anterolateral wall of the pelvis and the pelvic surface of the obturator membrane. The fibres converge rapidly towards the lesser sciatic foramen and end in four or five tendinous bands and leave the pelvis through the lesser sciatic foramen.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 41
Correct
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Most of the coagulation factors are serine proteases. Which of the following is not one of them?
Your Answer: Factor XIII
Explanation:Serine protease coagulation factors include: thrombin, plasmin, Factors X, XI and XII. Factor VIII and factor V are glycoproteins and factor XIII is a transglutaminase.
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This question is part of the following fields:
- General
- Physiology
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Question 42
Incorrect
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A 27 year old women had developed a darker complexion following a vacation to India. She had no erythema or tenderness. Her skin colour returned to normal over a period of 1 month. Which of the these substances is related to the biochemical change mentioned above?
Your Answer: Hemosiderin
Correct Answer: Tyrosine
Explanation:The tanning process can occur due to UV light exposure as a result of oxidation of tyrosine to dihydrophenylalanine with the help of the tyrosinase enzyme within the melanocytes. Hemosiderin can impart a brown colour due to breakdown of RBC but its usually due to a trauma and is known as haemochromatosis.
Lipofuscin gives a golden brown colour to the cell granules not the skin.
Homogentisic acid is part of a rare disease alkaptonuria, with characteristic black pigment deposition within the connective tissue.
Copper can impart a brown golden colour, but is not related to UV light exposure.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 43
Correct
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The most likely cause of prominent U waves on the electrocardiogram (ECG) of a patient is:
Your Answer: Hypokalaemia
Explanation:The U-wave, not always visible in ECGs, is thought to represent repolarisation of papillary muscles or Purkinje fibres. When seen, it is very small and occurs after the T-wave. Inverted U-waves indicate myocardial ischaemia or left ventricular volume overload. Prominent U-waves are most commonly seen in hypokalaemia. Other causes include hypercalcaemia, thyrotoxicosis, digitalis exposure, adrenaline and class 1A and 3 anti-arrhythmic agents. It can also be seen in congenital long-QT syndrome and in intracranial haemorrhage.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 44
Correct
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A 20-year old gentleman was brought to the emergency department with headache and nausea for 2 days. He also complained of intolerance to bright light and loud sounds. Lumbar puncture showed glucose < 45 mg/dl, protein > 5 mg/dl and neutrophil leucocytosis. The likely diagnosis is:
Your Answer: Meningitis
Explanation:Diagnosis of meningitis can be carried out with examination of cerebrospinal fluid (CSF) with a lumbar puncture (LP). In a case of bacterial meningitis, the CSF analysis will show:
– Opening pressure: > 180 mmH2O
– White blood cell count: 10–10 000/μl with neutrophil predominance
– Glucose: < 40 mg/dl – CSF glucose to serum glucose ratio: < 0.4 – Protein: > 4.5 mg/dl
– Gram stain: positive in > 60%
– Culture: positive in > 80%
– Latex agglutination: may be positive in meningitis due to Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Escherichia coli and group B streptococci
– Limulus, lysates: positive in Gram-negative meningitis
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This question is part of the following fields:
- Neurology
- Physiology
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Question 45
Correct
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After being admitted to the hospital, a 60-year-old man is administered sodium nitroprusside. Which class of drugs does nitroprusside belong to?
Your Answer: Vasodilators
Explanation:Sodium nitroprusside is a potent peripheral vasodilator that affects both arterioles and venules. It is often administered intravenously to patients who are experiencing a hypertensive emergency. It reduces both total peripheral resistance as well as venous return, so decreasing both preload and afterload. For this reason it can be used in severe cardiogenic heart failure where this combination of effects can act to increase cardiac output. It is administered by intravenous infusion. Onset is typically immediate and effects last for up to ten minutes. The duration of treatment should not exceed 72 hours.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 46
Correct
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Which one of the following muscles is innervated by the facial nerve?
Your Answer: Buccinator
Explanation:Buccinator is a muscle of facial expression and is therefore innervated by the facial nerve. The lateral pterygoid, masseter, anterior belly of digastric and temporalis are all muscles of mastication and therefore innervated by the mandibular division of the trigeminal nerve.
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This question is part of the following fields:
- Anatomy
- Head & Neck; Neurology
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Question 47
Correct
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Gram positive bacteria differ from gram negative bacteria due to the presence of which of the following structures?
Your Answer: Outer membrane
Explanation:The reason bacteria are either Gram-positive or Gram-negative is due to the structure of their cell envelope (the cell envelope is defined as the cell membrane and cell wall plus an outer membrane, if one is present.) Gram-positive bacteria, for example, retain the crystal violet due to the amount of peptidoglycan in the cell wall. It can be said therefore that the Gram-stain procedure separates bacteria into two broad categories based on structural differences in the cell envelope.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 48
Correct
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Which of the following foramina provides a passage through which the vestibulocochlear nerve, passes?
Your Answer: Internal acoustic meatus
Explanation:The internal auditory meatus is a canal within the petrous part of the temporal bone of the skull between the posterior cranial fossa and the inner ear. It provides a passage through which the vestibulocochlear nerve, the facial nerve, and the labyrinthine artery (an internal auditory branch of the basilar artery) can pass from inside the skull to structures of the inner ear and face.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 49
Incorrect
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Which of the following arteries, if ligated, will most likely affect blood supply to the pancreas?
Your Answer: Inferior phrenic
Correct Answer: Superior mesenteric
Explanation:The pancreas is a glandular organ in the body that produces important hormones such as insulin and glucagon. Its blood supply is from branches of the coeliac artery, superior mesenteric artery and the splenic artery. These are the arteries that if ligated, would affect blood supply to the pancreas.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 50
Incorrect
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What is the normal duration of the ST segment?
Your Answer: 0.02 s
Correct Answer: 0.08 s
Explanation:The ST segment lies between the QRS complex and the T-wave. The normal duration of the ST segment is 0.08 s. ST-segment elevation or depression may indicate myocardial ischaemia or infarction.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 51
Incorrect
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Regarding the coagulation cascade, Factor VII:
Your Answer: Is mainly synthesised by the vascular endothelium
Correct Answer: Is a serine protease
Explanation:Factor VII (FVII) is a zymogen for a vitamin K-dependent serine protease essential for the initiation of blood coagulation. It is synthesized primarily in the liver and circulates in plasma. Within the liver, hepatocytes are involved in the synthesis of most blood coagulation factors, such as fibrinogen, prothrombin, factor V, VII, IX, X, XI, XII, as well as protein C and S, and antithrombin, whereas liver sinusoidal endothelial cells produce factor VIII and von Willebrand factor.
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This question is part of the following fields:
- General
- Physiology
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Question 52
Incorrect
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Which of the following proteins acts as cofactor in the thrombin-induced activation of anticoagulant protein C?
Your Answer: Prekallikrein
Correct Answer: Thrombomodulin
Explanation:Thrombomodulin is a protein cofactor expressed on the surface of endothelial cells. Thrombomodulin binds with thrombin forming a complex which activates protein C, initiating the anticoagulant pathway.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 53
Correct
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Which of the following is likely to result in hematocolpos in a 12-year old girl?
Your Answer: Imperforate hymen
Explanation:Hematocolpos means accumulation of blood in vagina and hematometra is accumulation of blood in the uterus. These are most likely seen with an imperforate hymen; which is seen I 1 in 2000 females. If spontaneous resolution does not occur, treatment involves making a hole in the hymen to allow discharge of menstrual blood.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 54
Correct
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A specialist registrar was performing the bi-lateral surgical removal of the adrenal glands. He first removed the left adrenal gland before moving on to the right one. However, the registrar noticed that the removal of the right adrenal gland would be a challenge because of an overlying structure. What was this structure that overlies the right suprarenal glad?
Your Answer: Inferior vena cava
Explanation:The adrenal glands or the suprarenal glands are small glands that are found on top of each of the kidneys. They are retroperitoneal glands. The right adrenal gland is found on top of the right kidney and is closely associated with the inferior vena cava as it directly drains into this large vein. In the case where the right adrenal gland is to be surgically removed, the inferior vena cava might prove a problem to manoeuvre as it overlies the right suprarenal gland. The other blood vessels such as the aorta, right renal, superior mesenteric, splenic artery and the hepatic vein as well as the right crus are not closely associated with either of the suprarenal glands.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 55
Correct
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The thoracic duct :
Your Answer: varies in length from 38 to 45 cm
Explanation:The thoracic duct is the main drainage of lymph in the body. It varies in length from 38 to 45 cm and extends from the second lumbar vertebra to the root of the neck.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 56
Correct
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Which condition presents with a positive urine dipstick test for blood, but no blood cells on urine microscopy?
Your Answer: Myoglobinuria
Explanation:Myoglobinuria, or presence of myoglobulin in the urine is seen due to rhabdomyolysis (muscle destruction). Common causes of rhabdomyolysis include trauma, electrical injuries, burns, venom and drugs. Damaged muscle leads to release of myoglobin in the blood. Ideally, the released myoglobin gets filtered and excreted by the kidneys. However, excess myoglobin can occlude the renal filtration system leading to acute tubular necrosis and acute renal dysfunction.
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This question is part of the following fields:
- Pathology
- Renal
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Question 57
Correct
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The chest X-ray of an 10-year-old boy, that presented with low-grade fever and cough, revealed hilar enlargement and parenchymal consolidation in the middle lobes. These X-ray findings are more typical for which of the following diagnoses?
Your Answer: Pulmonary tuberculosis
Explanation:Primary pulmonary tuberculosis is seen in patients exposed to Mycobacterium tuberculosis for the firs time. The main radiographic findings in primary pulmonary tuberculosis include homogeneous parenchymal consolidation typically in the lower and middle lobes, lymphadenopathy, miliary opacities and pleural effusion.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 58
Incorrect
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Which of the following structures, is the area in which the superior cerebral veins drain into?
Your Answer: Great cerebral vein
Correct Answer: Superior sagittal sinus
Explanation:The superior cerebral veins are predominantly located on the superior aspect of the brain. They are 8 to 12 in number and they drain the lateral, medial and superior aspects of the cerebral hemispheres.
These veins drain into the superior sagittal sinus, also known as the superior longitudinal sinus – which is located along the attached margin of the falx cerebri.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 59
Incorrect
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When a penile tumour invades the subepithelial connective tissue of the penis, what is its stage?
Your Answer: T2
Correct Answer: T1
Explanation:The TNM staging used for penile cancer is as follows:
TX: primary tumour cannot be assessed
T0: primary tumour is not evident
Tis: carcinoma in situ is present
Ta: non-invasive verrucous carcinoma is present
T1: tumour is invading subepithelial connective tissue
T2: tumour is invading the corpora spongiosum or cavernosum
T3: tumour invading the urethra or prostate
T4: tumour invading other adjacent structures.
In this case, the patient has a T1 tumour.
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This question is part of the following fields:
- Pathology
- Urology
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Question 60
Incorrect
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Passing through the lesser sciatic foramen are the:
Your Answer: Inferior gluteal artery
Correct Answer: Pudendal nerve
Explanation:Structures that pass through the lesser sciatic foramen include:
– the pudendal nerve
– the nerve to obturator internus
– internal pudendal artery
– the tendon of obturator internus
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This question is part of the following fields:
- Anatomy
- Pelvis
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SESSION STATS - PERFORMANCE PER SPECIALTY
