-
Question 1
Correct
-
A patient is suspected to have a chromosomal abnormality. Which tumour and chromosomal association is correct?
Your Answer: Neuroblastoma – chromosome 1
Explanation:Neuroblastoma is associated with a deletion on chromosome 1 and inactivation of a suppressor gene. Neurofibromas and osteogenic sarcoma are associated with an abnormality on chromosome 17. Retinoblastoma (Rb) is associated with an abnormality on chromosome 13. Wilms’ tumours of the kidney are associated with an abnormality on chromosome 11.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 2
Incorrect
-
The wound healing process is documented in patients undergoing laparoscopic procedures. The port incisions are sutured closed and the wounds observed every few weeks for re-epithelialisation and tensile strength. Which substance is mostly likely to be found at a cellular level involved in wound healing?
Your Answer: Collagen
Correct Answer: Tyrosine kinase
Explanation:Cell surface growth factor receptors require intercellular proteins such as tyrosine kinase which are necessary to initiate a series of events that eventually lead to cell division and growth. Tyrosine kinase is an enzyme that transfers a phosphate group to the tyrosine residue in a protein. This phosphorylation will lead to an up regulation of the enzyme activity.
Fibronectin acts in the extracellular matrix to bind macromolecules (such as proteoglycans) via integrin receptors to aid attachment and migration of cells.
Laminin is an extracellular matrix component that is abundant in basement membranes.
Hyaluronic acid is one of the proteoglycans in the extracellular matrix.
Collagen fibres are part of the extracellular matrix that gives strength and stability to connective tissues.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 3
Incorrect
-
What is the percentage of bone calcium that is freely exchangeable with the extracellular fluid that is available for buffering changes in the calcium ion balance?
Your Answer: 10%
Correct Answer: 1%
Explanation:Around 1% of calcium in the body is available for buffering changes in calcium ion balance. These are mainly derived from the bone that are freely exchangeable with extracellular fluid.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 4
Correct
-
A patient with a long standing lower motor neuron lesion will have:
Your Answer: Muscle wasting
Explanation:Lower motor neurons (LMNs) connect the brainstem and spinal cord to muscle fibres. Damage to lower motor neurons is indicated by abnormal electromyographic potentials, fasciculations, paralysis, weakening and wasting of skeletal muscles.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 5
Correct
-
A young girl injured her arm following a fall down the steps On examination, it was found that her left proximal radioulnar joint had dislocated and the annular ligament was stretched. This will make which movement extremely painful?
Your Answer: Supination
Explanation:Supination is the rotation of the forearm so that the palm of the hand faces anteriorly. This is performed by the biceps brachii and supinator of the extensor muscles of the thumb. The opposite action of moving the palm from an anterior-facing position to a posterior-facing position is called pronation. Pronation is performed by the pronator teres and pronator quadratus.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 6
Correct
-
The gynaecologist suspects that her patient has a cervical cancer. What particular test should be done on this patient to screen for cervical cancer?
Your Answer: Pap smear
Explanation:Worldwide, approximately 500,000 new cases of cervical cancer and 274,000 deaths are attributable to cervical cancer yearly. This makes cervical cancer the second most common cause of death from cancer in women. The mainstay of cervical cancer screening has been the Papanicolaou test (Pap smear).
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 7
Correct
-
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.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 8
Correct
-
During a laparoscopic surgery, the surgeon visualizes the medical umbilical folds on the deep surface of the anterior abdominal wall. What causes the medial umbilical folds?
Your Answer: Obliterated umbilical arteries
Explanation:The medial umbilical ligament is a structure found on the deep surface of the anterior abdominal wall and is covered by the medial umbilical folds. It is a paired structure that represents the remnants of the fetal umbilical artery. They have no role in humans after birth other than to be used as a landmark for exploring the medial inguinal fossa during laparoscopic inguinal hernia repair.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 9
Correct
-
A lesion involving the lateral portion of the dorsal columns at the level of the nape of the neck will most likely affect:
Your Answer: Vibratory sensations from the ipsilateral arm
Explanation:At the level mentioned in the question, the lateral portion of dorsal columns comprises of the fasciculus cuneatus. Axons carrying the sensations of touch, vibration and proprioception from the ipsilateral arm enter the spinal cord and ascend in the fasciculus cuneatus, synapsing in the nucleus cuneatus of the caudal medulla. Secondary neurons from this nucleus give rise to internal arcuate fibres, which decussate and ascend to the thalamus as the medial lemniscus. Tertiary neurons from there project to the ipsilateral somatosensory cortex. Thus, any damage to the fasciculus cuneatus will result in a deficit in tactile, proprioceptive and vibratory sensations in the ipsilateral arm, and not the contralateral arm.
Fine motor control of the fingers is mainly carried by the ipsilateral lateral corticospinal tract in the lateral funiculus of the cord. Motor control of the contralateral foot is carried by the ipsilateral corticospinal tract in the lateral funiculus of the cord. Lack of sweating of the face could be produced by interruption of sympathetic innervation. Proprioception from the ipsilateral leg is carried by the fasciculus gracilis in the medial part of the dorsal columns.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 10
Incorrect
-
Following a bee sting, a women develops a 2cm red, raised, swollen lesion at the site of the sting . Which of the following findings is likely to be seen in this lesion?
Your Answer: Lymphocytic infiltration
Correct Answer: Vasodilation
Explanation:Inflammation is the immediate response of the body towards infections or irritations. The cardinal signs of inflammation are 1. redness/rubor, 2. tumour/swelling, 3.dolar/pain, 4.calor/heat and organ dysfunction (function laesa). Inflammation has 2 components; vascular and cellular. Blood vessels dilate upstream of the inflamed area leading to the rubor and calor and constrict downstream, increasing pressure and causing fluid to leak out of the capillary, resulting in swelling. The cellular component includes infiltration by neutrophils. Leukocyte arrival and functions include; 1. margination: cells marginated from the centre to the periphery of the vessel, 2. rolling: selectins are upregulated on the vessel walls, 3. adhesion: upregulation of the adhesion molecules ICAM and VCAM on the endothelium interact with integrins on the leukocytes resulting in adhesion, 4. diapedesis and chemotaxis: diapedesis is the transmigration of the leukocyte across the endothelium of the capillary and towards a chemotactic product and 5. phagocytosis: engulfing the offending substance/cell.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 11
Correct
-
The uterine artery arises from the?
Your Answer: Internal iliac artery
Explanation:The uterine artery arises from the anterior division of the internal iliac artery and runs medially on the levator ani towards the uterine cervix.
-
This question is part of the following fields:
- Anatomy
- Pelvis
-
-
Question 12
Correct
-
A 55-years-old man presented to the emergency department complaining of a squeezing sensation in his chest that has spread to his neck with associated worsening shortness of breath. Which of these laboratory tests would you ask for in this patient:
Your Answer: Creatine kinase-MB
Explanation:Creatine kinase-MB is a test that usually is ordered when the patient has chest pain as a cardiac marker. When a heart attack is suspected and a troponin test (which is more specific for heart damage), is not available CK-MB is ordered. There are 3 forms of CK: CK-MM, CK-BB and CK-MB. CK-MB is commonly found in heart tissue, therefore injured heart muscle cells release CK-MB into the blood. Elevated CK-MB levels indicate that it is probable that a person has recently had a heart attack.
-
This question is part of the following fields:
- Cardiovascular
- Pathology
-
-
Question 13
Correct
-
An explorative laparotomy is done on a 23 year old following a gunshot abdominal injury through the right iliac fossa. It is found that the ileocolic artery is severed and the bullet had perforated the caecum. From which branch does the ileocolic artery originate?
Your Answer: Superior mesenteric artery
Explanation:Ileocolic artery branches off from the superior mesenteric artery. It then divides to give a superior and inferior branch.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 14
Correct
-
An ECG of a 30 year old woman revealed low voltage QRS complexes. This patient is most probably suffering from?
Your Answer: Pericardial effusion
Explanation:The QRS complex is associated with current that results in the contraction of both the ventricles. As ventricles have more muscle mass than the atria, they result in a greater deflection on the ECG. The normal duration of a QRS complex is 10s. A wide and deep Q wave depicts myocardial infarction. Abnormalities in the QRS complex maybe indicative of a bundle block, ventricular tachycardia or hypertrophy of the ventricles. Low voltage QRS complexes are characteristic of pericarditis or a pericardial effusion.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 15
Correct
-
During an operation to repair a hiatal hernia, the coeliac branch of the posterior vagal trunk is injured. This damage would affect muscular movements as well as some secretory activities of the gastrointestinal tract. Which gastrointestinal segment is LEAST likely to be affected?
Your Answer: Sigmoid colon
Explanation:The vagus nerve supplies the parasympathetic fibres to the abdominal structures that are receive arterial supply from the coeliac trunk or superior mesenteric artery i.e. up to the transverse colon. The end of the transverse colon and the gastrointestinal structures distal to this point receive parasympathetic innervation from the pelvic splanchnic nerves and blood from the inferior mesenteric artery(IMA). The ascending colon, caecum, jejunum and ileum would all, thus, be affected by this damage. Sigmoid colon would not be affected.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 16
Correct
-
Where is the mental foramen located?
Your Answer: In the mandible
Explanation:The mental foramen is found bilaterally on the anterior surface of the mandible adjacent to the second premolar tooth. The mental nerve and terminal branches of the inferior alveolar nerve and mental artery leave the mandibular canal through it.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 17
Correct
-
A 22-year old man presented with a mass in his left scrotum which was more prominent when standing and felt like a 'bag of worms'. Examination revealed a non-tender mass along the spermatic cord. Also, the right testis was larger than the left testis. What is the likely diagnosis?
Your Answer: Varicocele
Explanation:Varicocele refers to dilatation and increased tortuosity of the pampiniform plexus – which is a network of veins found in spermatic cord that drain the testicle. Defective valves or extrinsic compression can result in outflow obstruction and cause dilatation near the testis. Normal diameter of the small vessels ranges from 0.5 – 1.5mm. A varicocele is a dilatation more than 2mm.
The plexus travels from the posterior aspect of testis into the inguinal canal with other structures forming the spermatic cord. They then form the testicular veins out of which the right testicular vein drains into the inferior vena cava and the left into the left renal vein.
It affects 15-20% men, and 40% of infertile males. Usually diagnosed in 15-25 years of age, they are rarely seen after 40 years of age. Because of the vertical path taken by the left testicular vein to drain into left renal vein, 98% idiopathic varicoceles occur on the left side. It is bilateral in 70% cases. Right-sided varicoceles are rare.
Symptoms include pain or heaviness in the testis, infertility, testicular atrophy, a palpable mass, which is non-tender and along the spermatic cord (resembling a ‘bag of worms’). The testis on the affected side might be smaller.
Diagnosis can be made by ultrasound. Provocative measures such as Valsalva manoeuvre or making the patient stand up to increase the dilatation by increasing the intra-abdominal venous pressure.
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 18
Incorrect
-
The nutcracker effect of the alimentary canal is described as a nutcracker-like compression caused by the aorta and the superior mesenteric arteries on a certain section of the alimentary canal leading to bowel obstruction. Which of the following parts of the alimentary canal is usually obstructed by this nutcracker compression of the two arteries?
Your Answer: Ileum
Correct Answer: Duodenum
Explanation:The ‘nutcracker effect’ is only seen in one part of the alimentary canal, and that is in the third part of the duodenum. This can happen when the superior mesenteric artery that passes across the duodenum and the aorta, posteriorly to the third part of the duodenum enlarges and starts compressing the duodenum. The result is an obstructed duodenum that inhibits passage of food.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 19
Incorrect
-
Chest X-ray of a 45-year old gentleman with a week history of pleurisy showed a small pneumothorax with moderate-sized pleural effusion. Arterial blood gas analysis showed p(CO2) = 23 mmHg, p(O2) = 234.5 mmHg, standard bicarbonate = 16 mmol/l. What are we most likely dealing with?
Your Answer: Compensated respiratory acidosis
Correct Answer: Compensated respiratory alkalosis
Explanation:Normal pH with low p(CO2) and low standard bicarbonate could indicate either compensated respiratory alkalosis or a compensated metabolic acidosis. However, the history of hyperventilation for 5 days (pleurisy) favours compensated respiratory alkalosis. Compensated metabolic acidosis would have been likely in a diabetic patient with fever, vomiting and high glucose (diabetic ketoacidosis).
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 20
Incorrect
-
A elderly patient with bulbar palsy is bed ridden. While swallowing he aspirates one of his tablets into his lungs. In which bronchopulmonary segments is it most likely to end up?
Your Answer: Medial segmental bronchus of the right middle lobe
Correct Answer: Superior segmental bronchus of the right inferior lobe
Explanation:Inhaled objects are more likely to enter the right lung for several reasons. First the right bronchus is shorter, wider and more vertical than the left bronchus. Also, the carina (a ridge-like structure at the point of tracheal bifurcation) is set a little towards the left. The superior segmental bronchus branches posteriorly off the intermediate bronchus or the inferior lobe bronchus and is thus more likely to receive the foreign body that enters the right main bronchus. The lingula is only found on the left lung. The terminal bronchiole is a very small space almost impossible for the tablet to lodge here.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 21
Correct
-
A 16 year-old boy was stabbed in the right supraclavicular fossa. The sharp object punctured the portion of the parietal pleura that extends above the first rib. What is the name of this portion of the parietal pleura?
Your Answer: Cupola
Explanation:Endothoracic fascia: the connective tissue (fascia) that is between the costal parietal pleura and the inner wall of the chest wall.
Costomediastinal recess: the point where the costal pleura becomes mediastinal pleura.
Costodiaphragmatic recess: is the lowest point of the pleural sac where the costal pleura becomes diaphragmatic pleura.
Cupola: the part of the parietal pleura that extends above the first rib level into the root of the neck.
Costocervical recess: this is a made-up term.
Peritracheal fascia: a layer of connective tissue that invests the trachea.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 22
Correct
-
Which of the following foramina will the ophthalmic artery pass through in order to reach the eye?
Your Answer: Optic canal
Explanation:The optic foramen is the opening to the optic canal. The canal is located in the sphenoid bone; it is bounded medially by the body of the sphenoid and laterally by the lesser wing of the sphenoid. The superior surface of the sphenoid bone is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the chiasmatic groove (optic groove). The groove ends on either side in the optic foramen, which transmits the optic nerve and ophthalmic artery into the orbital cavity. Compared to the optic nerve, the ophthalmic artery is located inferolaterally within the canal.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 23
Correct
-
Extracellular body fluid as compared with intracellular body fluid:
Your Answer: Is relatively rich in glucose
Explanation:The percentages of body water contained in various fluid compartments add up to total body water (TBW). This water makes up a significant fraction of the human body, both by weight and by volume. Ensuring the right amount of body water is part of fluid balance, an aspect of homeostasis. The extracellular fluid (ECF) includes all fluids outside the cells. This fluid can be divided into three fluid departments: interstitial (in the tissue spaces) fluid, blood plasma and lymph, and specialised compartments called transcellular fluid. The extracellular fluid surrounds all the cells in the body and is in equilibrium with the intracellular fluid. So, its composition must remain fairly constant even though substances are passing into and out of the cells. The interstitial fluid, though called a fluid, is in a reality a gel-like composition made up of: water, proteoglycan molecules and collagen. The extracellular fluid constitutes 40% of total body water, with intracellular fluid making up the remaining 60%. It is relatively rich in glucose.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 24
Incorrect
-
An elderly, diabetic man has firm, tender nodules at the base of his left middle and ring fingers, which he can't extend fully. What's the most likely diagnosis?
Your Answer: Dystrophic calcification
Correct Answer: Fibromatosis
Explanation:This case is suggestive of Dupuytren’s contracture due to palmar fibromatosis. Its incidence is higher in men over the age of 45 years, and it increases in patients with diabetes, alcoholism, or epilepsy. These nodules are benign, usually appearing as a tender nodule in the palm which becomes painless. The disease has an aggressive clinical behaviour and recurs frequently.
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 25
Correct
-
All the following statements are FALSE regarding the ophthalmic division of the trigeminal nerve, except:
Your Answer: The ophthalmic nerve is the smallest branch of the trigeminal nerve
Explanation:The ophthalmic nerve is the smallest of the three trigeminal divisions. The cutaneous branches of the ophthalmic nerve supply the conjunctiva, the skin over the forehead, the upper eyelid, and much of the external surface of the nose.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 26
Correct
-
Muscles and tendons in the planter region of the foot mainly take blood supply from:
Your Answer: Posterior tibial artery
Explanation:The posterior tibial artery is the main source of blood supply to the posterior compartment of the leg.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 27
Incorrect
-
During an operation to repair an indirect inguinal hernia, you are asked to indicate the position of the deep inguinal ring. You indicate this as being:
Your Answer: Medial to the inferior epigastric artery
Correct Answer: Above the midpoint of the inguinal ligament
Explanation:The deep inguinal ring is near the midpoint of the inguinal ligament, below the anterior superior iliac spine. It is lateral to the inferior epigastric artery. The superficial ring, however, is found above the pubic tubercle. The supravesical fossa is the space between the median and medial umbilical folds.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 28
Correct
-
Purkinje fibres in the heart conduct action potentials at the rate of:
Your Answer: 1.5–4.0 m/s
Explanation:Purkinje fibres control the heart rate along with the sinoatrial node (SA node) and the atrioventricular node (AV node). The QRS complex is associated with the impulse passing through the Purkinje fibres. These fibres conduct action potential about six times faster than the velocity in normal cardiac muscle.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 29
Correct
-
The specialist registrar, while performing the repair of an infrarenal abdominal aortic aneurysm, decides not to re-implant the inferior mesenteric artery into the repaired abdominal aorta. She says that an anastomotic artery running along the border of the large intestine is good enough to supply blood to the territory of the inferior mesenteric artery. Which vessel is she referring to?
Your Answer: Marginal
Explanation:The marginal artery is a key anastomosis for the large intestine that runs around the border of the large intestine and is formed by the anastomosis of the branches of the ileocolic artery, right colic artery, middle colic artery, left colic artery and sigmoid artery. If a small artery is occluded, these branches allow blood to reach all segments of the colon.
The arcades are anastomotic loops between the arteries that provide alternative pathways for blood flow. They are more prominent in the small intestine than the large intestine.
Arteriae rectae are small branches that run from the marginal artery to reach the colon.
The ileocolic artery is the branch of the superior mesenteric artery that supplies the caecum, appendix and terminal part of the ileum.
The coronary arteries supply blood to the heart.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 30
Correct
-
A 45-year-old man presented to the doctor complaining of a flank pain and episodes of haematuria. Abdominal ultrasound revealed a left renal mass and the patient underwent a nephrectomy. Histopathological pattern was triphasic with blastemal, epithelial, and stromal components. The pathologist suggested the tumour resulted from the lack of a tumour suppressor gene on chromosome 11. Which of the following tumours is the pathologist most likely suggesting?
Your Answer: Wilms’ tumour
Explanation:Wilms’ tumour is one of the most common malignant tumours of childhood but it can also rarely be found in adults. In biopsy, classical histopathological findings include the triphasic pattern composed by blastemal, epithelial, and stromal elements. First symptoms in children include an abdominal palpable mass, while in adults pain and haematuria are the most common complaints. Deletions of tumours’ suppressor genes on chromosome 11 are usually associated with Wilms’ tumour.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 31
Incorrect
-
A 30-year-old man is brought to the emergency department suffering from extreme dehydration, and subsequent hypotension and tachycardia. Which part of the kidney will compensate for this loss?
Your Answer: Thick limb of loop of Henlé
Correct Answer: Collecting ducts
Explanation:The collecting duct system of the kidney consists of a series of tubules and ducts that physically connect nephrons to a minor calyx or directly to the renal pelvis. The collecting duct system is the last component of the kidney to influence the body’s electrolyte and fluid balance. In humans, the system accounts for 4–5% of the kidney’s reabsorption of sodium and 5% of the kidney’s reabsorption of water. At times of extreme dehydration, over 24% of the filtered water may be reabsorbed in the collecting duct system.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 32
Correct
-
A diabetic 58-year-old man, after the injection of radiographic contrast, has a decreased urine output and decreased level of consciousness. Which of the following conditions has he most likely developed
Your Answer: Acute tubular necrosis
Explanation:Acute tubular necrosis (ATN) involves damage to the tubule cells of the kidneys and is the most common cause of acute kidney injury. ATN in the majority of the cases is caused by ischaemia of the kidneys due to lack of perfusion and oxygenation but it may also occur due to poison or harmful substance. Contrast used for radiology may cause ATN in patients with several risk factors e.g. diabetic nephropathy. Symptoms may include oliguria, nausea, fluid retention, fatigue and decreased consciousness.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 33
Correct
-
A 5-year-old child diagnosed with nephrotic syndrome developed generalised oedema. What is the mechanism for the development of oedema in patients with nephrotic syndrome?
Your Answer: Decreased colloid osmotic pressure
Explanation:The development of oedema in nephrotic syndrome has traditionally been viewed as an underfill mechanism. According to this view, urinary loss of protein results in hypoalbuminemia and decreased plasma oncotic pressure. As a result, plasma water translocates out of the intravascular space and results in a decrease in intravascular volume. In response to the underfilled circulation, effector mechanisms are then activated that signal the kidney to secondarily retain salt and water. While an underfill mechanism may be responsible for oedema formation in a minority of patients, recent clinical and experimental findings would suggest that oedema formation in most nephrotic patients is the result of primary salt retention. Direct measurements of blood and plasma volume or measurement of neurohumoral markers that indirectly reflect effective circulatory volume are mostly consistent with either euvolemia or a volume expanded state. The ability to maintain plasma volume in the setting of a decreased plasma oncotic pressure is achieved by alterations in transcapillary exchange mechanisms known to occur in the setting of hypoalbuminemia that limit excessive capillary fluid filtration.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 34
Correct
-
A patient had sudden complete loss of vision of the right eye. Fundoscopy showed the distinct cherry red spot on the retina. Which of the following arteries was occluded?
Your Answer: Central artery of the retina
Explanation:The central retinal artery supplies all the nerve fibres that form the optic nerve, which carries the visual information to the lateral geniculate nucleus of the thalamus. Thus if the central retinal artery gets occluded, there is complete loss of vision in that eye and the entire retina (with the exception of the fovea) becomes pale, swollen and opaque while the central fovea still appears reddish (this is because the choroid colour shows through). This is the basis of the famous Cherry red spot seen on examination of the retina on fundoscopy of a central retinal artery occlusion (CRAO).
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 35
Correct
-
When a patient is standing erect, pleural fluid would tend to accumulate in which part of the pleural space?
Your Answer: Costodiaphragmatic recess
Explanation:The costo-diaphragmatic recess is the lowest extent of the pleural cavity or sac. Any fluid in the pleura will by gravity accumulate here when a patient is standing erect.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 36
Incorrect
-
Question 37
Correct
-
What is the name of the cutaneous branch of the posterior primary ramus of C2?
Your Answer: Greater occipital nerve
Explanation:The dorsal primary ramus of the spinal nerve C2 is the greater occipital nerve which provides cutaneous innervation to the skin of the back of the head. The ventral primary ramus gives off the great auricular nerve, the lesser occipital nerve and the ansa cervicalis.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 38
Correct
-
Which of the following structures is not easily palpable?
Your Answer: Styloid process of the temporal bone
Explanation:The styloid process is a thin, pointed process that projects antero-inferiorly from the base of the petrous temporal bone. It can vary in length from a short, stubby process to a slender, four to five centimetre rod. It forms from the cranial elements of the second pharyngeal arch. The tympanic plate of the temporal bone ensheathes the base of this process. The pointed, projecting portion of the process provides attachment to the stylohyoid and stylomandibular ligaments, and to three muscles – the styloglossus, stylohyoid, and stylopharyngeus. As the styloid process is covered by the various muscles, it is not easily palpable in live subjects.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 39
Incorrect
-
During a laparoscopic inguinal hernia repair, the surgeon finds an artery in the extraperitoneal connective tissue (preperitoneal fat) that courses vertically and just medial to the bowel as the bowel passes through the abdominal wall. Which artery is this?
Your Answer: Superficial circumflex iliac
Correct Answer: Inferior epigastric
Explanation:The inferior epigastric artery comes from the external iliac artery just above the inguinal ligament to curve forward in the subperitoneal tissue and then ascend obliquely along the medial margin of the deep inguinal ring. It continues to ascend between the rectus abdominis and the posterior lamella of its sheath after piercing the fascia transversalis and passing anterior to the linea semicircularis. Finally it gives off numerous branches that anastomose above the umbilicus with the superior epigastric branch of the internal mammary artery and with the lower intercostal arteries. As this artery ascends obliquely upwards from its origin it lies along the lower medial margins of the deep inguinal ring and posterior to the start of the spermatic cord. It is found in the preperitoneal fat of the abdomen lying just superficial to the peritoneum and forms the lateral umbilical fold. Hernias that pass lateral to this are indirect and medial to this, direct hernias.
The deep circumflex artery travels along the iliac crest on the inner surface of the abdominal wall. It is very lateral to the abdominal wall and hernias would pass medial to it.
The superficial circumflex iliac, superficial epigastric, superficial external pudendal arteries are all superficial arteries found in the superficial fascia.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 40
Incorrect
-
A lad involved in a road traffic accident is rushed to casualty where physical examination reveals that he has limited extension of his right humerus. Which of the following nerves is most likely to have been injured?
Your Answer: Suprascapular nerve
Correct Answer: Thoracodorsal nerve
Explanation:Extension of the humerus is a function of the latissimus dorsi. This muscle is supplied by the thoracodorsal nerve which is a branch of the posterior cord of the plexus whose fibres are derived from cranial nerves V, VI and VII.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 41
Incorrect
-
An 80 year-old lady presents to the out patient clinic complaining of chest pain of 2 months' duration with a normal electrocardiogram and cardiac enzymes. A computed tomographic scan is done which reveals a mass lesion involving a structure in the middle mediastinum. Which among the following structures could be involved?
Your Answer: Thoracic duct
Correct Answer: Ascending aorta
Explanation:The middle mediastinum is the broadest part of the mediastinal cavity containing the heart enclosed in the pericardium, ascending aorta, lower half of the superior vena cava with the azygos vein opening into it, the bifurcation of the trachea and the two bronchi, the pulmonary artery with its branches, pulmonary veins, phrenic nerves and bronchial lymph nodes. The most likely structure involved is the ascending aorta, perhaps with an aneurysm.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 42
Correct
-
A woman that presented with dyspnoea, chest pain and cough was found to have a serous pleural effusion. This finding is most likely to be associated with which of the following conditions?
Your Answer: Congestive heart failure
Explanation:A pleural effusion is defined as an abnormal collection of fluid in the pleural space. Pleural effusion can result from excess fluid production or decreased absorption or both. Thoracentesis and laboratory testing help determine the origin of the accumulated fluid. Serous fluid accumulation in the pleural space indicates the presence of a hydrothorax and is most likely to develop secondary to congestive heart failure.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 43
Incorrect
-
A blood sample from a patient with polycythaemia vera will show which of the following abnormalities?
Your Answer: Decreased MCV
Correct Answer: High platelet count
Explanation:Polycythaemia is a condition that results in an increase in the total number of red blood cells (RBCs) in the blood. It can be due to a myeloproliferative syndrome, chronically low oxygen levels or rarely malignancy. In primary polycythaemia/ polycythaemia vera the increase is due to an abnormality in the bone marrow, resulting in increased RBCs, white blood cells (WBCs) and platelets. In secondary polycythaemia the increase occurs due to high levels of erythropoietin either artificially or naturally. The increase is about 6-8 million/cm3 of blood. A type of secondary polycythaemia is physiological polycythaemia where people living in high altitudes who are exposed to hypoxic conditions produce more erythropoietin as a compensatory mechanism for thin oxygen and low oxygen partial pressure.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 44
Correct
-
The ability of the bacteria to cause disease or its virulence is related to :
Your Answer: Toxin and enzyme production
Explanation:The pathogenicity of an organism or its ability to cause disease is determined by its virulence factors. Many bacteria produce virulence factors that inhibit the host’s immune system. The virulence factors of bacteria are typically proteins or other molecules that are synthesized by enzymes. These proteins are coded for by genes in chromosomal DNA, bacteriophage DNA or plasmids. The proteins made by the bacteria can poison the host cells and cause tissue damage.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 45
Correct
-
A 63-year-old woman complains of a new, persisting headache. She is diagnosed with vasculitis and the histopathological sample revealed giant-cell arteritis. What is the most probable diagnose?
Your Answer: Temporal arteritis
Explanation:Giant cell arteritis (GCA), also known as temporal arteritis, is the most common systemic inflammatory vasculitis that occurs in adults. It is of unknown aetiology and affects arteries large to small however the involvement of the superficial temporal arteries is almost always present. Other commonly affected arteries include the ophthalmic, occipital and vertebral arteries, therefore GCA can result in systemic, neurologic, and ophthalmologic complications. GCA usually is found in patients older than 50 years of age and should always be considered in the differential diagnosis of a new-onset headache accompanied by an elevated erythrocyte sedimentation rate. Diagnosis depends on the results of artery biopsy.
-
This question is part of the following fields:
- Cardiovascular
- Pathology
-
-
Question 46
Incorrect
-
What is the most likely cause of bilateral gynaecomastia in a 55-year old male?
Your Answer: History of antidepressant drug therapy
Correct Answer: Hepatic failure
Explanation:Hypertrophy of breast tissue in males is known as gynaecomastia. It is normally due to proliferation of stroma and not of mammary ducts. Physiological gynaecomastia can occur during puberty and is often transient, bilateral, symmetrical and possibly tender. Gynaecomastia can occur during old age too, but is usually unilateral. Other causes include hepatic or renal failure, endocrinological disorders, drugs (anabolic steroids, antineoplastic drugs, calcium channel blockers, cimetidine, digitalis, oestrogens, isoniazid, ketoconazole, methadone, metronidazole, reserpine, spironolactone, theophylline), and marijuana. It should not be confused with malignancy which is often hard, asymmetric and fixed to the dermis or fascia. Treatment if indicated, includes withdrawal of the causative factor or treatment of the underlying disorder.
-
This question is part of the following fields:
- Pathology
- Women's Health
-
-
Question 47
Correct
-
A 10-year-old boy was sent for an x-ray of the leg because he was complaining of pain and swelling. The x-ray showed the classic sign of Codman's triangle. What is the most likely diagnosis of this patient?
Your Answer: Osteosarcoma
Explanation:Codman’s triangle is the triangular area of new subperiosteal bone that is created when a lesion, often a tumour, raises the periosteum away from the bone. The main causes for this sign are osteosarcoma, Ewing’s sarcoma, eumycetoma, and a subperiosteal abscess.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 48
Correct
-
Which of the following cytokines produced by the T cell induce MHC-II proteins?
Your Answer: γ-Interferon
Explanation:Interferons elicit a non-specific antiviral activity by inducing specific RNA synthesis and expression of proteins in neighbouring cells. Common interferon inducers are viruses, double-stranded RNA and micro-organisms. INF-γ is produced mainly by CD4+, CD8+ T cells and less commonly by B cells and natural killer cells. INF-γ has antiviral and antiparasitic activity but its main biological activity appears to be immunomodulatory. Among its many functions are activation of macrophages and enhanced expression of MHC-II proteins or macrophages.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 49
Correct
-
Which of the following conditions is characterized by generalised oedema due to effusion of fluid into the extracellular space?
Your Answer: Anasarca
Explanation:Anasarca (or ‘generalised oedema’) is a condition characterised by widespread swelling of the skin due to effusion of fluid into the extracellular space. It is usually caused by liver failure (cirrhosis of the liver), renal failure/disease, right-sided heart failure, as well as severe malnutrition/protein deficiency.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 50
Incorrect
-
A significantly elevated white cell count of 50 x 109/l with 5% blasts and raised leucocyte alkaline phosphatase is seen in which of the following conditions?
Your Answer: Acute myelogenous leukaemia
Correct Answer: Leukaemoid reaction
Explanation:Non-neoplastic proliferation of leucocytes causes an increase in leukocyte alkaline phosphatase (LAP). This is referred to as ‘leukemoid reaction’ because of the similarity to leukaemia with an increased white cell count (>50 × 109/l) with immature forms. Causes of leukemoid reaction includes haemorrhage, drugs (glucocorticoids, all-trans retinoic acid etc), infections such as tuberculosis and pertussis, and as a paraneoplastic phenomenon. Leukemoid reaction can also be seen in infancy as a feature of trisomy 21. This is usually a benign condition, but can be a response to a disease state. Differential diagnosis include chronic myelogenous leukaemia (CML).
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 51
Incorrect
-
Both the arytenoid muscles and the lateral cricoarytenoid muscles perform this action on the glottis:
Your Answer: Stretch
Correct Answer: Adduction
Explanation:Both the arytenoid and the cricoartenoid muscles close the glottis. The lateral cricoarytenoid muscles extend from the lateral cricoid cartilage to the muscular process of the arytenoid cartilage. By rotating the arytenoid cartilages medially, these muscles adduct the vocal cords and thereby close the rima glottidis. The arytenoid muscle adducts or approximates the arytenoid cartilages, and thus closes the aperture of the glottis.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 52
Correct
-
The vagus nerve passes through which of the following foramen?
Your Answer: Jugular foramen
Explanation:The jugular foramen is a large foramen in the base of the skull. It is located behind the carotid canal and is formed in front by the petrous portion of the temporal bone, and behind by the occipital bone. Cranial nerves IX, X, and XI and the internal jugular vein pass through the jugular foramen.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 53
Correct
-
A 20-year old boy presented with low grade fever, night sweats and weakness over two months. On examination, he had multiple, non-tender, cervical, supraclavicular and axillary adenopathy. Microscopy of lymph node biopsy showed the presence of Reed-Sternberg cells. He is likely suffering from:
Your Answer: Hodgkin’s lymphoma
Explanation:Hodgkin’s lymphoma is a disease characterized by malignant proliferation of cells of the lymphoreticular system. It can be localized or disseminated, and can involve the nodes, spleen, liver and marrow. Symptoms of the disease include non-tender lymphadenopathy, fever, night sweats, weight loss, itching and hepatosplenomegaly. Histologically, the involved nodes show the presence of Reed-Sternberg cells, which are large, binucleated cells, in a heterogenous cellular infiltrate of histiocytes, lymphocytes, monocytes, plasma cells and eosinophils.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 54
Incorrect
-
Which nerve mediates the sensation to itch from the skin that is just over the base of the spine of your scapula?
Your Answer:
Correct Answer: Dorsal primary ramus of C7
Explanation:The first branches off spinal nerves are called the dorsal and ventral rami. The dorsal rami mediate sensation of the skin over the back and motor supply to the true muscles of the back whilst the ventral rami gives sensation to the skin over the limbs and the skin that is over the ventral side of the trunk. It also gives motor supply to the skeletal muscles of the neck, the trunk and extremities. Hence, itchiness of the part of the skin that is over the spine of the scapula would be mediated by the primary ramus of C7. Accessory nerve doesn’t have any sensory innervation.
-
This question is part of the following fields:
- Anatomy
- Neurology
-
-
Question 55
Incorrect
-
A 14-year old girl presented with a 2cm, mobile, cystic mass in the midline of her neck. Fine needle aspiration of the mass revealed clear fluid. This is most likely a case of:
Your Answer:
Correct Answer: Thyroglossal duct cyst
Explanation:Thyroglossal cyst is the most common congenital thyroid anomaly which is clinically significant and affects women more than men. It is a vestigial remnant of developing thyroid. Although the thyroglossal cyst can develop anywhere along the thyroglossal duct, the most common site is in the midline between the isthmus of thyroid and hyoid bone, or just above the hyoid. Thyroglossal cysts are also associated with ectopic thyroid tissue. Clinically, the cyst moves upward with protrusion of the tongue. Rarely, the persistent duct can become malignant (thyroglossal duct carcinoma) where the cancerous cells arise in the ectopic thyroid tissue that are deposited along the duct. Exposure to radiation is a predisposing factor.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 56
Incorrect
-
What is the nerve supply of the muscle that is inserted onto the crest of the lesser tubercle of the humerus?
Your Answer:
Correct Answer: Lower subscapular
Explanation:The muscle is the subscapularis muscle which is supplied by the lower subscapular nerve.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 57
Incorrect
-
Cancer of the testis most likely metastases to which set of lymph nodes?
Your Answer:
Correct Answer: Aortic
Explanation:The lymphatic drainage of an organ is related to its blood supply. The lymphatic drainage of the testis drains along the testicular artery to reach the lymph nodes along the aorta.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 58
Incorrect
-
An experiment was conducted in which the skeletal muscle protein (not smooth muscle) involved in contraction was selectively inhibited. Which protein was inhibited?
Your Answer:
Correct Answer: Troponin
Explanation:The mechanism of contraction of smooth muscles is different from that of skeletal muscles in which the contractile protein is troponin whilst in smooth muscle contraction is a protein called calmodulin. Calmodulin reacts with calcium ions and stimulates the formation of myosin crossbridges.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 59
Incorrect
-
A 42-year old woman presents to the doctor with jaundice. Her investigations show conjugated hyperbilirubinemia, raised urine bilirubin levels and low urine urobilinogen levels. What is the likely cause of her jaundice?
Your Answer:
Correct Answer: Blockage of the common bile duct
Explanation:The description of the patient here fits the diagnosis of obstructive jaundice or cholestasis, which results in conjugated hyperbilirubinemia. Cholestasis occurs due to impairment of bile flow, which can be anywhere from the liver cell canaliculus to the ampulla of Vater. Causes can be divided into intrahepatic and extrahepatic.
– Intrahepatic causes include hepatitis, drug toxicity, alcoholic liver disease, primary biliary cirrhosis, cholestasis of pregnancy and metastatic cancer.
– Extrahepatic causes include common duct stone, pancreatic cancer, benign stricture of the common duct, ductal carcinoma, pancreatitis and sclerosing cholangitis.
There is absence of bile constituents in the intestine, which causes spillage in the systemic circulation. Symptoms include pale stools, dark urine, pruritus, malabsorption leading to steatorrhea and deficiency of fat-soluble vitamins. Chronic cases can result in osteoporosis or osteomalacia due to vitamin D deficiency and Ca2+ malabsorption. Cholesterol and phospholipid retention produces hyperlipidaemia despite fat malabsorption (although increased liver synthesis and decreased plasma esterification of cholesterol also contribute); triglyceride levels are largely unaffected. The lipids circulate as a unique, low-density lipoprotein called lipoprotein X.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 60
Incorrect
-
A 30 year-old male patient sustained a sharp blow to the right side of the head, over the temporal region during a vehicular accident. This resulted to the rupture of the principal artery that supplies the meninges. Which artery is affected?
Your Answer:
Correct Answer: Middle meningeal artery
Explanation:The middle meningeal artery is typically the third branch of the first part of the maxillary artery, one of the two terminal branches of the external carotid artery. After branching off the maxillary artery in the infratemporal fossa, it runs through the foramen spinosum to supply the dura mater and the calvaria. The middle meningeal artery is the largest of the three (paired) arteries that supply the meninges, the others being the anterior meningeal artery and the posterior meningeal artery. The anterior branch of the middle meningeal artery runs beneath the pterion. It is vulnerable to injury at this point, where the skull is thin. Rupture of the artery may give rise to an epidural hematoma .An injured middle meningeal artery is the most common cause of an epidural hematoma.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 61
Incorrect
-
Injury to this nerve will affect the function of the palatoglossus and levator veli palatini muscles:
Your Answer:
Correct Answer: Cranial nerve X
Explanation:The vagus nerve (cranial nerve X) innervates both the palatoglossus and levator veli palatini muscles.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 62
Incorrect
-
What occurs during cellular atrophy?
Your Answer:
Correct Answer: Cell size decreases
Explanation:Atrophy is the decrease in the size of cells, tissues, or organs. There are several causes including inadequate nutrition, poor circulation, loss of hormonal support or nerve supply, disuse, lack of exercise, or disease. An increase in cell size is termed hypertrophy which is distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number.
-
This question is part of the following fields:
- Cell Injury & Wound Healing; Urology
- Pathology
-
-
Question 63
Incorrect
-
Which part of the nephron would have to be damaged to stop the reabsorption of the majority of salt and water?
Your Answer:
Correct Answer: Proximal tubule
Explanation:The proximal tubule is the portion of the duct system of the nephron of the kidney which leads from Bowman’s capsule to the loop of Henle. It is conventionally divided into the proximal convoluted tubule (PCT) and the proximal straight tubule (PST). The proximal tubule reabsorbs the majority (about two-thirds) of filtered salt and water. This is done in an essentially iso-osmotic manner. Both the luminal salt concentration and the luminal osmolality remain constant (and equal to plasma values) along the entire length of the proximal tubule. Water and salt are reabsorbed proportionally because the water is dependent on and coupled with the active reabsorption of Na+. The water permeability of the proximal tubule is high and therefore a significant transepithelial osmotic gradient is not possible.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 64
Incorrect
-
An infant, 5 weeks and 6 days old born with a large sub-aortic ventricular septal defect, is prepared for pulmonary artery banding through a left thoracotomy (the child is not fit for a surgical closure). The surgeon initially passes his index finger immediately behind two great arteries in the pericardial sac to mobilise the great arteries in order to pass the tape around the pulmonary artery. Into which space is the surgeon's finger inserted?
Your Answer:
Correct Answer: Transverse pericardial sinus
Explanation:Cardiac notch: is an indentation on the left lung of the heart.
Coronary sinus: a venous sinus on the surface of the heart (the posterior aspect) that receives blood from the smaller veins that drain the heart.
Coronary sulcus: a groove on the heart between the atria and ventricles.
Transverse pericardial sinus: located behind the aorta and pulmonary trunk and anterior to the superior vena cava.
Oblique pericardial sinus: located behind the left atrium. Accessed from the inferior side (or the apex) of the heart upwards.
Horizontal pericardial sinus: this is a made-up term.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 65
Incorrect
-
Which of the following is the cause of flattened (notched) T waves on electrocardiogram (ECG)?
Your Answer:
Correct Answer: Hypokalaemia
Explanation:The T-wave is formed due to ventricular repolarisation. Normally, it is seen as a positive wave. It can be normally inverted (negative) in V1 (occasionally in V2-3 in African-Americans/Afro-Caribbeans). Hyperacute T-waves are the earliest ECG change of acute myocardial infarction. ECG findings of hyperkalaemia include high, tent-shaped T-waves, a small P-wave and a wide QRS complex. Hypokalaemia results in flattened (notched) T-waves, U-waves, ST-segment depression and prolonged QT interval.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 66
Incorrect
-
A 27-year old lady is shot in the chest. The bullet enters superior to the upper edge of the clavicle. She had difficulty in breathing which is interpreted by the A&E physician as a likely indicator of a collapsed lung. If that is the case, what portion of the pleura is most likely to have been punctured?
Your Answer:
Correct Answer: Cupola
Explanation:The cupola is part of the pleura that extends above the first rib into the root of the lung. Most likely to injured in a stab above the level of the clavicle.
Costodiaphragmatic recess: the lowest extent of the pleural sac.
Pulmonary ligament: is a fold of pleura located below the root of the lung.
Mediastinal pleura: part of the pleura that lines the mediastinal cavity.
Hilar reflection is the part of the pleura where the visceral pleura of the lung reflects to become continuous with the parietal pleura.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 67
Incorrect
-
What's the nodal stage of a testicular seminoma if several lymph nodes between 2cm and 5cm are found?
Your Answer:
Correct Answer: N2
Explanation:According to the American Joint Committee on Cancer (AJCC) 2002 guidelines, the nodal staging of testicular seminoma is the following:
N0: no regional lymph node metastases
N1: metastasis with lymph nodes 2 cm or less in their greatest dimension or multiple lymph nodes, none more than 2 cm
N2: metastasis with lymph nodes greater than 2 cm but not greater than 5 cm in their greatest dimension, or multiple lymph nodes, any one mass greater than 2 cm, but not more than 5 cm
N3: metastasis with lymph nodes greater than 5 cm in their greatest dimension.
The patient in this case has N2 testicular seminoma. This TNM staging is extremely important because treatment options are decided depending on this classification.
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 68
Incorrect
-
How much blood can the pulmonary vessels of a 45-year-old healthy man accommodate when he is at rest?
Your Answer:
Correct Answer: 500 ml
Explanation:Pulmonary circulation is the portion of the cardiovascular system which carries deoxygenated blood away from the heart, to the lungs, and returns oxygenated blood back to the heart. The vessels of the pulmonary circulation are very compliant (easily distensible) and so typically accommodate about 500 ml of blood in an adult man. This large lung blood volume can serve as a reservoir for the left ventricle, particularly during periods when left ventricular output momentarily exceeds venous return.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 69
Incorrect
-
The renal cortex and medulla, if seen under the microscope, is lacking one of the following:
Your Answer:
Correct Answer: Squamous epithelium
Explanation:Capillaries, Henle’s loop, collecting ducts, Bertin columns and type IV collagen in glomerular basement membrane are all structures present in the renal cortex or medulla. The squamous epithelium is the only one that is lacking in both the renal cortex and medulla, because normally it is not found above the outer urethra.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 70
Incorrect
-
A patient is suspected to have Blastomyces dermatidis infection. The patient contracted the disease most likely through which port of entry?
Your Answer:
Correct Answer: Respiratory tract
Explanation:Blastomycosis disease is a fungal infection acquired through inhalation of the spores. It caused by the organism Blastomyces dermatitidis and manifests as a primary lung infection in about 70% of cases. The onset is relatively slow and symptoms are suggestive of pneumonia.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 71
Incorrect
-
Which of the following diseases can cause paraesthesia along the distribution of the median nerve of the hand, especially after activities which require flexion and extension of the wrist?
Your Answer:
Correct Answer: Carpal tunnel syndrome
Explanation:Carpal tunnel syndrome tends to occur in women between the ages of 30-50. There are many risk factors, including diabetes, hypothyroidism, obesity, pregnancy, and repetitive wrist work. Symptoms include pain in the hand and wrist, tingling, and numbness distributed along the median nerve (the palmar side of the thumb, the index and middle fingers, and the radial half of the ring finger), which worsens at night.
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 72
Incorrect
-
Hyperplastic arteriosclerosis with fibrinoid necrosis, petechial haemorrhages, microinfarcts in the kidneys and elevated plasma renin are common findings in which of the following patients?
Your Answer:
Correct Answer: A 45-year-old woman with scleroderma
Explanation:Scleroderma, also known as systemic sclerosis, is a chronic disease of the connective tissue. Involvement of the kidneys occurs in patients with diffuse scleroderma, causing rapid onset of high blood pressure with hyperreninemia, thrombotic microangiopathy, and progressive renal failure.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 73
Incorrect
-
A 47-year-old male smoker, who had been self-medicating with oral steroids for the last two years due to persistent breathlessness presented to the doctor complaining of a productive cough, fever and chest pain. A chest X-ray revealed bilateral patchy opacities. He was diagnosed with bilateral bronchopneumonia. Which of these organisms is most probably causing these findings?
Your Answer:
Correct Answer: Nocardia asteroides
Explanation:Nocardia is a Gram-positive aerobic actinomycete. Several species have been identified but the most common human pathogen is Nocardia asteroides. The predominant clinical finding in the majority of patients affected by nocardiosis is pulmonary disease. Predisposing factors for pulmonary nocardiosis include leukaemia, human immunodeficiency virus (HIV) infection, organ transplantation, diabetes and receiving prolonged corticosteroids.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 74
Incorrect
-
A histology report of a cervical biopsy taken from a patient with tuberculosis revealed the presence of epithelioid cells. What are these cells formed from?
Your Answer:
Correct Answer: Macrophages
Explanation:Granulomas formed in tuberculosis are called tubercles and are made up polynuclear phagocytes, Langhans cells and epithelioid cells. Macrophages when enlarged, consist of abundant cytoplasm and have a tendency of arranging themselves very closely to each other representing epithelial cells. These enlarged macrophages are therefore termed as epithelioid cells.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 75
Incorrect
-
A 7-year-old boy with facial oedema was brought to the hospital by his parents. Renal function is normal and urinalysis revealed the presence of a profound proteinuria. Which of the following is the most probable cause of these findings?
Your Answer:
Correct Answer: Minimal-change disease
Explanation:Minimal-change disease (MCD) refers to a histopathologic glomerular lesion, typically found in children, that is almost always associated with nephrotic syndrome. The most noticeable symptom of MCD is oedema, which can develop very rapidly. Due to the renal loss of proteins muscle wasting and growth failure may be seen in children. Renal function is usually not affected and a proteinuria of more than 40 mg/h/m2 is the only abnormal finding in urinalysis.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 76
Incorrect
-
Which muscle extends to form the cremasteric muscle?
Your Answer:
Correct Answer: Internal abdominal oblique muscle
Explanation:The cremasteric muscle is a thin layer of muscle composed of several fasciculi that originate from the middle of the inguinal ligament. At its point of origin the fibres are continuous with the fibres of internal oblique and sometimes with the transversus abdominis. It then passes along the lateral side of the spermatic cord and descends with it through the superficial inguinal ring on the front and sides of the cord.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 77
Incorrect
-
Which of the following muscles is solely contained in the anterior triangle of the neck and divides the anterior triangle into three smaller triangles?
Your Answer:
Correct Answer: Digastric
Explanation:The digastric muscle is a small muscle located under the jaw. It lies below the body of the mandible, and extends, in a curved form, from the mastoid process to the symphysis menti. The digastric divides the anterior triangle of the neck into three smaller triangles:
– The submaxillary triangle, bounded above by the lower border of the body of the mandible and a line drawn from its angle to the sternocleidomastoid, below by the posterior belly of the digastric and the stylohyoid and in front by the anterior belly of the digastric
– The carotid triangle, bounded above by the posterior belly of the digastric and stylohyoid, behind by the sternocleidomastoid and below by the omohyoid
– The suprahyoid or submental triangle, bounded laterally by the anterior belly of the digastric, medially by the midline of the neck from the hyoid bone to the symphysis menti and inferiorly by the body of the hyoid bone.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 78
Incorrect
-
A mechanic sustained a deep laceration to his right cubital fossa which resulted in him unable to move the proximal radioulnar joint of his right arm. Which muscles was affected?
Your Answer:
Correct Answer: Pronator teres
Explanation:The correct answer is the pronator teres muscle. This muscle arises from 2 heads of origin: the humerus and ulnar. Between the 2 heads is the site of entrance of median nerve to the forearm. This muscle acts on the proximal radio-ulnar joint to rotate the radius on the ulna, otherwise known as pronation. It also assists in forearm flexion if the radius is fixed.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 79
Incorrect
-
A 38 year-old man falls on an outstretched hand. X-rays indicate an anterior dislocation of one of the carpal bones. Which carpal bone is most commonly dislocated?
Your Answer:
Correct Answer: Lunate
Explanation:The scaphoid bone is the most commonly fractured carpal bone and has an increased risk of avascular necrosis.
The lunate is the most commonly dislocated carpal bone. The displaced bone may compress the median nerve in the carpal tunnel.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 80
Incorrect
-
When inserting a chest drain anteriorly into the second intercostal space, one must identify the second costal cartilage by palpating which landmark?
Your Answer:
Correct Answer: Sternal angle
Explanation:The sternal angle is the site for identification of the second rib as the second rib is attached to the sternum at this point.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 81
Incorrect
-
Which of the following brings about a reduction in gastric blood flow?
Your Answer:
Correct Answer: Vasopressin
Explanation:Gastric blood flow is increased by vagal stimulation, gastrin, histamine and acetylcholine as they stimulate gastric section and the production of vasodilator metabolites. Acetylcholine and histamine also have a direct action on the gastric arterioles. Similarly, gastric blood flow is reduced by inhibitors of secretion – catecholamines, secretin and vasopressin.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 82
Incorrect
-
A 45-year-old-female is suspected to have a pulmonary mass. Supposing that she has a neoplasm, which of the following are most commonly found to involve the lung:
Your Answer:
Correct Answer: Pulmonary metastases
Explanation:Lung metastases occur when a cancer started in another part of the body (primary site) spreads to the lungs. The lungs are among the most common site where cancer can spread due to its rich systemic venous drainage, almost every type of cancer can spread to the lung. The most common types of cancer that spread to the lung are breast, colorectal, kidney, testicular, bladder, prostate, head and neck cancers.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 83
Incorrect
-
Pseudomonas aeruginosa is a multidrug resistant pathogen that causes hospital-acquired infections. It is usually treated with piperacillin or another antibiotic. Which of the following is the other antibiotic?
Your Answer:
Correct Answer: Azlocillin
Explanation:Azlocillin, like piperacillin, is an acylampicillin antibiotic with an extended spectrum of activity and greater in vitro potency than the carboxypenicillins. Azlocillin is similar to mezlocillin and piperacillin. It demonstrates antibacterial activity against a broad spectrum of bacteria, including Pseudomonas aeruginosa.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 84
Incorrect
-
Two boys were playing when one of them brought the forearm of the other behind his back. This resulted in a stretching of the lateral rotator of the arm. Which of the following muscles was most likely to have been involved?
Your Answer:
Correct Answer: Infraspinatus
Explanation:There are two lateral rotators of the arm, the infraspinatus and the teres minor muscles. The infraspinatus muscle receives nerve supply from C5 and C6 via the suprascapular nerve, whilst the teres minor is supplied by C5 via the axillary nerve.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 85
Incorrect
-
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:
Correct 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.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 86
Incorrect
-
Skeletal muscle fibres are divided into two basic types, type I (slow-twitch fibres) and type II (fast-twitch fibres). Fast muscle fibres do which of the following:
Your Answer:
Correct Answer: Use anaerobic metabolism
Explanation:Skeletal muscles are divided into two types:
1) type I also known as the slow twitch fibres. They use oxygen for their metabolism and as a result they have a high endurance potential. To support this they have abundant mitochondria and myoglobin, so they appear red/dark.
2) type II fibres also called fast twitch fibres, are low endurance fibres used during anaerobic metabolism. They are required for short bursts of strength and cannot sustain contractions for long periods of time.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 87
Incorrect
-
13 year old girl developed sun burnt cheeks after spending the day playing on the beach. What is the underlying mechanism to her injury?
Your Answer:
Correct Answer: Free radical injury
Explanation:Free radicals are a by-product of chemical reactions with an unpaired electron in their outer most shell. They are capable of causing wide spread damage to cells. They can cause autolytic reactions thereby converting the reactants into free radicals. By absorbing sun light, the energy is used to hydrolyse water into hydroxyl (OH) and hydrogen (H) free radicals which can cause injury by lipid peroxidation of membranes, oxidative modification of proteins and damage to the DNA structure.
-
This question is part of the following fields:
- Cell Injury & Wound Healing; Dermatology
- Pathology
-
-
Question 88
Incorrect
-
A 55 year-old construction worker is diagnosed with malignant mesothelioma. Exposure to which substance increased his risk in developing mesothelioma?
Your Answer:
Correct Answer: Asbestos
Explanation:Mesothelioma is a rare, aggressive form of cancer that develops in the lining of the lungs, abdomen or heart. It is linked to inhalation of asbestos commonly used in ship building and the insulation industry. It has no known cure and has a very poor prognosis.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 89
Incorrect
-
A 50-year-old man is diagnosed with emphysema and cirrhosis of the liver. Which of the following condition may be the cause of both cirrhosis and emphysema in this patient?
Your Answer:
Correct Answer: Alpha1-antitrypsin deficiency
Explanation:Alpha-1 antitrypsin (A1AT) deficiency is a condition characterised by the lack of a protein that protects the lungs and liver from damage, called alpha1-antytripsin. The main complications of this condition are liver diseases such as cirrhosis and chronic hepatitis, due to accumulation of abnormal alpha 1-antytripsin and emphysema due to loss of the proteolytic protection of the lungs.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 90
Incorrect
-
During a clinical rotation in the ENT clinic, you observe a flexible bronchoscopy. As the scope is passed down the trachea, you see a cartilaginous structure that resembles a ship's keel and separates the right and the left main stem bronchi. This structure is the:
Your Answer:
Correct Answer: Carina
Explanation:The carina (a keel-like cartilage) is found at the bifurcation of the trachea separating the right from the left main stem bronchi. It is a little more to the left than to the right.
The cricoid cartilage is the inferior and posterior cartilage of the larynx.
The costal cartilage on the other hand elongates the ribs anteriorly and contribute to the elasticity of the thoracic cage.
The pulmonary ligament is a fold of pleura located below the root of the lung.
Tracheal rings are rings of cartilage that support the trachea.
Peritracheal fascia is a layer of connective tissue that invests the trachea from the outside and is not visible on bronchoscopy.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 91
Incorrect
-
A construction worker is brought to the A&E after a fall on site. The patient is conscious but complains of inability to feel his legs. A neurological examination reveals that he has no cutaneous sensation from his umbilicus to his toes. What is the likely level of the spinal cord that is injured?
Your Answer:
Correct Answer: T10
Explanation:The umbilicus has a relatively consistent position in humans and thus serves as an important land mark. The skin around the waist at the level of the umbilicus is supplied by the tenth thoracic spinal nerve (T10 dermatome).
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 92
Incorrect
-
A 20-year-old woman had profuse watery diarrhoea for 2 days. She felt dizzy and weak, and thus decided to seek medical attention. At the emergency room her BP was 80/60 mmHg with a pulse of 118/min. What is the most appropriate intravenous treatment that should be given?
Your Answer:
Correct Answer: Isotonic saline
Explanation:Normal saline is typically the first fluid used when hypovolemia is severe enough to threaten the adequacy of blood circulation. It is isotonic and has long been believed to be the safest fluid to give quickly in large volumes.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 93
Incorrect
-
What are the derivatives of the first brachial arch?
Your Answer:
Correct Answer: Gives rise to the sphenomandibular ligament
Explanation:The first brachial arch (mandibular) gives rise to the mandibular and maxillary processes. Muscles and bones of this process originate within the arch’s mesoderm. The first arch cartilage (Meckel’s) ossifies to form the incus and malleus of the middle ear. Its perichondrium gives rise to he sphenomandibular ligament and through intermembraneous ossification after the mandible forms, the rest of the cartilage disappears. Muscles of the first arch include: mylohyoid, tensor tympany and palati, temporalis, masseter and lateral pterygoids and the anterior belly of the epigastric. This first arch is supplied by the trigeminal nerve.
-
This question is part of the following fields:
- Anatomy
- Embryology
-
-
Question 94
Incorrect
-
A 59-year old gentleman admitted for elective cholecystectomy was found to have a haemoglobin 12.5 g/dl, haematocrit 37%, mean corpuscular volume 90 fl, platelet count 185 × 109/l, and white blood cell count 32 × 109/l; along with multiple, small mature lymphocytes on peripheral smear. The likely diagnosis is:
Your Answer:
Correct Answer: Chronic lymphocytic leukaemia
Explanation:CLL or chronic lymphocytic leukaemia is the most common leukaemia seen in the Western world. Twice more common in men than women, the incidence of CLL increases with age. About 75% cases are seen in patients aged more than 60 years. The blood, marrow, spleen and lymph nodes all undergo infiltration, eventually leading to haematopoiesis (anaemia, neutropenia, thrombocytopenia), hepatomegaly, splenomegaly and decreased production of immunoglobulin. In 98% cases, CD+5 B cells undergo malignant transformation.
Often diagnosed on blood tests while being evaluated for lymphadenopathy, CLL causes symptoms like fatigue, anorexia, weight loss, pallor, dyspnoea on exertion, abdominal fullness or distension. Findings include multiple lymphadenopathy with minimal-to- moderate hepatomegaly and splenomegaly. Increased susceptibility to infections is seen. Herpes Zoster is common. Diffuse or maculopapular skin infiltration can also be seen in T-cell CLL.
Diagnosis is by examination of peripheral blood smear and marrow: hallmark being a sustained, absolute leucocytosis (>5 ×109/l) and increased lymphocytes in the marrow (>30%). Other findings can include hypogammaglobulinemia (<15% of cases) and, rarely, raised lactate dehydrogenase (LDH). Only 10% cases demonstrate moderate anaemia and/or thrombocytopenia.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 95
Incorrect
-
Which of the following morphological characteristic is a salient feature of a pure apoptotic cell?
Your Answer:
Correct Answer: Chromatin condensation
Explanation:Apoptosis is the programmed death of cells which occurs as a normal and controlled part of an organism’s growth or development. The changes which occur in this process include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, chromosomal DNA fragmentation, and global mRNA decay. The cell membrane however remains intact and the dead cells are phagocytosed prior to any content leakage and thus inflammatory response.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 96
Incorrect
-
A 77-year-old woman's renal function is tested. The following results were obtained during a 24-h period:
Urine flow rate: 2. 0 ml/min
Urine inulin: 0.5 mg/ml
Plasma inulin: 0.02 mg/ml
Urine urea: 220 mmol/l
Plasma urea: 5 mmol/l.
What is the urea clearance?Your Answer:
Correct Answer: 88 ml/min
Explanation:Urea is reabsorbed in the inner medullary collecting ducts of the nephrons. The clearance (C) of any substance can be calculated as follows: C = (U × V)/P, where U and P are the urine and plasma concentrations of the substance, respectively and V is the urine flow rate. So, glomerular filtration rate = (0.220 × 2. 0)/0.005 = 88 ml/min.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 97
Incorrect
-
A 20 year lady is brought to the A&E following a road accident. She is hypotensive and a CT scan of the abdomen reveals a shattered spleen. An emergency splenectomy is performed where the splenic artery is ligated right at its origin. Which of the following arteries will have a diminished blood flow owing to ligation of the splenic artery at its origin?
Your Answer:
Correct Answer: Left gastroepiploic
Explanation:Ligation of the splenic artery right at its point of origin should cut off blood flow in its branches. The following are the branches of the splenic artery: pancreatic branches, short gastric branches and left gastroepiploic arteries.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 98
Incorrect
-
Which of the following organs of the abdominal cavity is completely covered by the peritoneum?
Your Answer:
Correct Answer: Spleen
Explanation:Of the organs listed, the spleen is the only organ that is completely intraperitoneal, that is entirely in the peritoneum. Other completely intraperitoneal organs include the stomach, liver, appendix and the small intestines. The kidney, Inferior vena cava, aorta and the suprarenal glands are all retroperitoneal organs. The pancreas and the duodenum are partially retroperitoneal, with the tail of the pancreas in the peritoneum found in the splenorenal ligament while only the first part of the duodenum is intraperitoneal. For the intraperitoneal organs remember SALTD SPRSS
S = Stomach
A = Appendix
L = Liver
T = Transverse colon
D = Duodenum (only the 1st part)
S = Small intestines
P = Pancreas (only the tail)
R = Rectum (only the upper 3rd)
S = Sigmoid colon
S = Spleen
For retroperitoneal, just remember SADPUCKER:
S = suprarenal glands
A = Aorta and IVC
D = Duodenum (all but the 1st part)
P = Pancreas (all but the tail)
U = Ureter and bladder
C = Colon (ascending and descending)
K = Kidneys
E = Oesophagus
R = Rectum (Lower two-thirds)
For secondarily retroperitoneal remember ‘Pussy Cat Dolls“:
P = Pancreas
C = Colon (only ascending and descending)
D = Duodenum (only parts 2-4) -
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 99
Incorrect
-
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:
Correct 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.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 100
Incorrect
-
If the blood flow is constant, oxygen extraction by tissues will show the greatest decrease due to which of the following interventions?
Your Answer:
Correct Answer: Tissue cooling
Explanation:With a constant blood flow to a given tissue bed, there will be an increase in oxygen extraction by the tissue with the following; an increase in tissue metabolism and oxygen requirements: warming (or fever), exercise, catecholamines and thyroxine. With cooling, the demand for oxygen decreases, leading to decreased oxygen extraction.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 101
Incorrect
-
A 40 year old man sustained a fracture to the surgical neck of his left humerus. Which of the following arteries is suspected to be injured in this case?
Your Answer:
Correct Answer: Posterior humeral circumflex
Explanation:The posterior humeral circumflex artery arises from the axillary artery and runs with the axillary nerve through the quadrangular space which is bounded laterally by the surgical neck of the humerus. After winding around the surgical neck of the humerus, it is distributed to the deltoid muscle and the shoulder joint. Thus fractures in the surgical neck of the humerus could result in an injury to this artery.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 102
Incorrect
-
Which of the following abnormalities can be seen in patients with hypermagnesemia?
Your Answer:
Correct Answer: Respiratory depression
Explanation:Hypermagnesemia is an electrolyte disturbance in which there is a high level of magnesium in the blood. It is defined as a level greater than 1.1 mmol/L. Symptoms include weakness, confusion, decreased breathing rate, and cardiac arrest.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 103
Incorrect
-
A 56-year-old man undergoes tests to determine his renal function. His results over a period of 24 hours were:
Urine flow rate: 2. 0 ml/min
Urine inulin: 1.0 mg/ml
Plasma inulin: 0.01 mg/ml
Urine urea: 260 mmol/l
Plasma urea: 7 mmol/l
What is the glomerular filtration rate?Your Answer:
Correct Answer: 200 ml/min
Explanation:Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal (kidney) glomerular capillaries into the Bowman’s capsule per unit time. GFR is equal to the inulin clearance because inulin is freely filtered into Bowman’s capsule but is not reabsorbed or secreted. The clearance (C) of any substance can be calculated as follows: C = (U × V)/P, where U and P are the urine and plasma concentrations of the substance, respectively and V is the urine flow rate. Thus, glomerular filtration rate = (1.0 × 2. 0)/0.01 = 200 ml/min.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 104
Incorrect
-
A 60-year old patient having a history of cholelithiasis that led to recurrent pain, bloating, nausea and vomiting, was scheduled for surgery to have the gallbladder removed. During the cholecystectomy, the registrar conducting the procedure accidentally punctured a blood vessel that lies immediately posterior to the omental foramen and blood filled the operating field. Which of the following blood vessels was likely punctured?
Your Answer:
Correct Answer: Inferior vena cava
Explanation:The omental foramen is the pathway that connects the greater peritoneal sac and the lesser peritoneal sac. The omental foramen is bordered posteriorly by the inferior vena cava. This is the blood vessel that would most likely be punctured.
The aorta and its branch, the renal artery, lie postero-lateral to the omental foramen and are deeper than the inferior vena cava hence making them less likely to be injured.
The hepatic portal vein, the hepatic artery and the superior mesenteric vein borders the omental foramen anteriorly and would not be injured by a jab on the posterior border of the omental foramen.
Finally, the splenic artery is found in the splenorenal ligament that borders the omental foramen laterally to the left.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 105
Incorrect
-
The ostium of the maxillary sinus opens into which of the following structures?
Your Answer:
Correct Answer: Middle meatus
Explanation:The maxillary sinuses usually develop symmetrically. The maxillary sinus ostium drains into the infundibulum which joins the hiatus semilunaris and drains into the middle meatus.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 106
Incorrect
-
The occipital artery is accompanied by which nerve as it arises from the external carotid artery?
Your Answer:
Correct Answer: Hypoglossal nerve (CN XII)
Explanation:Three main types of variations in the relations of the occipital artery and the hypoglossal nerve are found according to the level at which the nerve crosses the external carotid artery and the point of origin of the occipital artery. In Type I, the hypoglossal nerve crosses the external carotid artery inferior to the origin of the occipital artery; in Type II, the nerve crosses the external carotid artery at the level of origin of the occipital artery; and in Type III, it crosses superior to that level. In Type III the occipital artery makes a loop around the hypoglossal nerve and is in a position to pull and exert pressure on the nerve. This possibility should be taken into consideration in the diagnosis of peripheral paresis or paralysis of the tongue and during surgery in this area.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 107
Incorrect
-
During laparoscopic surgery to repair a direct inguinal hernia in a 68-year old man, the surgeon asked the registrar to look at the medial inguinal fossa to identify the direct inguinal hernia. To do so, she would have to look at the area that is between the:
Your Answer:
Correct Answer: Medial umbilical ligament and inferior epigastric artery
Explanation:The medial umbilical fold is made by the medial umbilical ligament-which is the obliterated portion of the umbilical artery, while the lateral umbilical fold is a fold of peritoneum over the inferior epigastric vessels. The median umbilical fold is a midline structure made by the median umbilical ligament i.e. the obliterated urachus. The medial inguinal fossa is the space on the inner abdominal wall between the medial umbilical fold and the lateral umbilical fold. It is place in the abdominal wall where there is an area of weak fascia i.e. the inguinal triangle through which direct inguinal hernias break through. The lateral inguinal fossa on the other hand is a space lateral to the lateral umbilical fold. Indirect inguinal hernias push through this space.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 108
Incorrect
-
When one is silently counting, what part of his brain will show increased regional cerebral blood flow (rCBF)?
Your Answer:
Correct Answer: Supplementary motor area
Explanation:Regional cerebral blood flow (rCBF) increases in the superior speech cortex (supplementary motor area) during periods of silent counting, whereas speaking aloud will do so in the motor cortex and medial temporal lobe, along with the superior speech cortex.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 109
Incorrect
-
The chest X-ray of a 72 year old patient reveals the presence of a round lesion containing an air-fluid level in the left lung. These findings are most probably suggestive of:
Your Answer:
Correct Answer: Lung abscess
Explanation:Lung abscesses are collections of pus within the lung that arise most commonly as a complication of aspiration pneumonia caused by oral anaerobes. Older patients are more at risk due to poor oral hygiene, gingivitis an inability to handle their oral secretions due to other diseases. Chest X-ray most commonly reveals the appearance of an irregularly shaped cavity with an air-fluid level.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 110
Incorrect
-
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:
Correct 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
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 111
Incorrect
-
Which of the following structures is derived from the dorsal mesogastrium of the stomach during the development of the gut?
Your Answer:
Correct Answer: Greater omentum
Explanation:In a developing foetus, the stomach has two mesogastria from which most of the abdominal ligaments develop. These two mesogastria are the; ventral mesogastrium and the dorsal mesogastrium. During the embryological development of the gut, different organs develop in each mesogastrium; the spleen and pancreas in the dorsal mesogastrium while the liver in the ventral mesogastrium (with their associated ligaments). In the dorsal mesogastrium the following structures develop; the greater omentum (containing the gastrophrenic ligament and the gastrocolic ligament), gastrosplenic ligament, mesentery, splenorenal ligament and phrenicocolic ligament. The structures that develop from the ventral mesogastrium include the; lesser omentum (containing the hepatoduodenal ligament and the hepatogastric ligament) in association with the liver; the coronary ligament (left triangular ligament, right triangular ligament and hepatorenal ligament) and the falciform ligament (round ligament of liver and ligamentum venosum within).
There are also folds that develop from the dorsal mesogastrium which include; umbilical folds, supravesical fossa, medial inguinal fossa, lateral umbilical fold, lateral inguinal fossa and Ileocecal fold.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 112
Incorrect
-
From which of the following cells is heparin produced?
Your Answer:
Correct Answer: Mast cells
Explanation:Heparin is a natural highly-sulphated glycosaminoglycan that has anticoagulant functions. It is produced by the body basophils and mast cells.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 113
Incorrect
-
A 40 year old man suffered severe trauma following an MVA. His BP is 70/33 mmhg, heart rate of 140 beats/mins and very feeble pulse. He was transfused 3 units of blood resulting in his BP returning to 100/70 and his heart rate to 90 beats/min. What decreased following transfusion?
Your Answer:
Correct Answer: Total peripheral resistance
Explanation:The patient is in hypovolemic shock, he is transfused with blood to replace the volume lost. It is important not only to replace fluids but stop active bleeding in resuscitation. Fluid replacement will result in a decreased sympathetic discharge and adequate ventricular filling thus reducing total peripheral resistance and increasing cardiac output and cardiac filling pressures.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 114
Incorrect
-
A 45-year old with sarcoidosis has enlarged tracheobronchial lymph nodes. Which nerve is most likely to be irritated in this patient?
Your Answer:
Correct Answer: Left recurrent laryngeal
Explanation:Tracheobronchial lymph nodes are located at the bifurcation of the trachea and are in three groups i.e. the right superior, left superior and inferior. The aorta arches over the left bronchus near the point of tracheal bifurcation. Thus, the nerves that are closely associated with the aorta might be irritated if these nodes become inflamed. The left recurrent laryngeal nerve is such a nerve. The phrenic nerves, both the left and the right, are lateral and thus would not be affected. The right recurrent nerve loops around the right subclavian artery and is distant from this area. The right vagus artery is not associated with the aorta and the sympathetic chain is located in the posterior chest parallel to the vertebra, also not associated with the tracheobronchial tree.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 115
Incorrect
-
During clinic, a medical student conducts a physical examination on a teenage boy with a lump in the inguinal region. The lump is protruding from the superficial inguinal ring. The student correctly concluded that it was:
Your Answer:
Correct Answer: Either a direct or an indirect inguinal hernia
Explanation:It is not possible to tell if an inguinal hernia is direct or indirect just by palpating it. Despite the fact that indirect inguinal hernias commonly come out of the superficial inguinal ring to enter the scrotum, direct inguinal hernia might still do this.
Femoral hernia goes through the femoral ring into the femoral canal (has nothing to do with the superficial inguinal ring).
Superficial inguinal lymph nodes lie in the superficial fascia parallel to the inguinal ligament; it would therefore feel more superficial and would not be mistaken for a hernia protruding through the inguinal ring.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 116
Incorrect
-
What is the primary function of the Kupffer cells found in the liver?
Your Answer:
Correct Answer: Recycling of old red blood cells
Explanation:Kupffer cells found in the liver are part of the monocyte-reticular system. They are specialised macrophages and primarily function to recycle old and damaged RBCs. The RBCs are phagocytosed and the haemoglobin is broken down into haem and globin. The haem is further broken down into iron that is recycled and bilirubin that is conjugated with glucuronic acid and excreted in the bile.
-
This question is part of the following fields:
- Inflammation & Immunology; Hepatobiliary
- Pathology
-
-
Question 117
Incorrect
-
A textbook of cardiac surgery explains that while doing a left pneumonectomy, a surgeon must be careful to avoid injury to a vital structure that leaves an impression on the mediastinal surface of the left lung. Which structure is it referring to?
Your Answer:
Correct Answer: Aortic arch
Explanation:Structures that leave an impression on the mediastinal surface of the left lung include: the oesophagus, subclavian artery, brachiocephalic vein, first rib, thymus, the heart, the diaphragm, descending aorta and arch of the aorta. The other structures form an impression on the mediastinal aspect of the right lung.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 118
Incorrect
-
The Carpal tunnel does NOT contain:
Your Answer:
Correct Answer: Flexor carpi ulnaris
Explanation:The contents of the carpal tunnel include:
– Median nerve
– Flexor digitorum supervicialis
– Flexor digitorum profundus
– Flexor policis longus
– Flexor carpi radialis
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 119
Incorrect
-
Laboratory findings in a patient with dark urine and yellowish skin revealed a prolonged prothrombin time. Which of the following is the most likely cause of this finding?
Your Answer:
Correct Answer: Liver damage
Explanation:Various conditions may prolong the prothrombin time (PT), including: warfarin use, vitamin K deficiency, liver disease, disseminated intravascular coagulopathy, hypofibrinogenemia, heparin infusion, massive blood transfusion and hypothermia. Liver disease causes prolonging of PT due to diminished synthesis of clotting factors. Dark urine colour and jaundice are indicators of the presence of a liver disease in this patient.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 120
Incorrect
-
Which of these is secreted by both macrophages and muscle cells?
Your Answer:
Correct Answer: Interleukin-6
Explanation:IL-6 is secreted by the T cells and macrophages and is a pro inflammatory cytokine. It is secreted in response to trauma e.g. burns and tissue damage that leads to inflammation. Apart from this its is also a myokine and is elevated due to muscle contraction. Other functions include: stimulate osteoclast formation when secreted by osteoblasts, mediate fever in acute phase response and are responsible for energy metabolism in muscle and fatty tissues. Inhibitors of IL-6 e.g. oestrogen are used as a treatment for postmenopausal osteoporosis.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 121
Incorrect
-
A 44-year old gentleman presented to the hospital in congestive cardiac failure. On further investigation, he was found to have a right-sided retroperitoneal mass. On enquiry, he gave a history of intermittent hypertensive attacks. 24-hour urine specimen revealed raised metanephrine and vanillylmandelic acid levels. What is the likely diagnosis?
Your Answer:
Correct Answer: Pheochromocytoma
Explanation:A neuroendocrine tumour of the chromaffin cells in adrenal medulla, pheochromocytoma secretes excessive catecholamines – adrenaline (epinephrine) and noradrenaline (norepinephrine). Pheochromocytomas are also known as the ‘10% tumour’. This is because 10% of them are bilateral, 10% are malignant, and 10% are extra-adrenal. Extra-adrenal paragangliomas (also known as extra-adrenal pheochromocytomas) are less common than pheochromocytomas and arise in the ganglia of sympathetic nervous system. Around 25% of pheochromocytomas are familial. Symptoms are described as feeling of ‘impending doom’, and include tachycardia, hypertension, palpitations, anxiety, headaches and pallor. Orthostatic hypertension is typically seen where there is a more than 100 mmHg fall in systolic pressure when the patient stands up. Pheochromocytomas can also lead to malignant hypertension. Diagnosis is by measurement of catecholamines and metanephrines in blood or in 24-hour urine, after exclusion of other possible causes such as stress, hypoglycaemia and drugs (methyldopa, dopamine agonists, ganglion-blocking antihypertensive). Imaging is also needed to localize the tumour. Localization of the tumour can also be done by Iodine-131 meta-iodobenzylguanidine (I131-MIBG) imaging.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 122
Incorrect
-
Where is the foramen ovale located?
Your Answer:
Correct Answer: Sphenoid
Explanation:The foramen ovale is an oval shaped opening in the middle cranial fossa located at the posterior base of the greater wing of the sphenoid bone, lateral to the lingula. It transmits the mandibular division of the trigeminal nerve (CN Vc), accessory meningeal artery, emissary veins between the cavernous sinuses and pterygoid plexus, otic ganglion, and occasionally the nervus spinosus and lesser petrosal nerve.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 123
Incorrect
-
A 31 -year-old female patient had a blood gas done on presentation to the emergency department. She was found to have a metabolic acidosis and decreased anion gap. The most likely cause of these findings in this patient would be?
Your Answer:
Correct Answer: Hypoalbuminemia
Explanation:A low anion gap might be caused by alterations in serum protein levels, primarily albumin (hypoalbuminemia), increased levels of calcium (hypercalcaemia) and magnesium (hypermagnesemia) or bromide and lithium intoxication. However, the commonest cause is hypoalbuminemia, thus if the albumin concentration falls, the anion gap will also be lower. The anion gap should be corrected upwards by 2.5 mmol/l for every 10g/l fall in the serum albumin.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 124
Incorrect
-
Which tumour site is more commonly involved in adults than in children?
Your Answer:
Correct Answer: Lung
Explanation:In adults, the most common primary site of tumour is in the lungs, compared to children wherein the most common primary site is the blood.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 125
Incorrect
-
A 30-year-old female was alarmed when she started to experience hair loss and balding, however, she also noted increased hair on her face and body and developed an acne breakout. Deepening of her voice also became prominent. She was referred to an oncologist and was diagnosed with a hormone-producing tumour. What is the most likely diagnosis ?
Your Answer:
Correct Answer: Arrhenoblastoma
Explanation:Arrhenoblastoma, known as ‘Sertoli–Leydig tumour’ is a rare ovarian stromal neoplasm that secretes testosterone. It is mostly seen in women in the reproductive years. The key clinical features of this tumour is due to excessive production of testosterone which leads to progressive masculinisation in a woman who was typical normal beforehand. The lesion tends to grow slowly and rarely metastasises. Treatment is surgical removal of the tumour and the prognosis is generally good.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 126
Incorrect
-
Which of the following features is indicative of poor prognosis in a case of breast carcinoma?
Your Answer:
Correct Answer: Axillary lymph node metastases
Explanation:Lymphatic spread indicates poor prognosis. Presence of family history is not a prognostic factor despite being linked to higher incidence. Aneuploidy is a poor prognostic factor. A breast tumour positive for oestrogen receptors is a good prognostic factor as it increases the responsiveness of the tumour to certain therapies. In-situ tumours carry the best prognosis.
-
This question is part of the following fields:
- Pathology
- Women's Health
-
-
Question 127
Incorrect
-
Which of the following conditions can present with multiple abscesses that may discharge sulphur granules?
Your Answer:
Correct Answer: Actinomycosis
Explanation:Actinomycosis is primarily caused by any of the several members of the bacterial genus Actinomyces. These bacteria are generally anaerobes. And can cause multiple abscesses that may discharge sulphur granules.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 128
Incorrect
-
Different substances have different renal clearance rates. Which of the following substances should have the lowest renal clearance rate in a healthy patient?
Your Answer:
Correct Answer: Glucose
Explanation:Under normal conditions the renal clearance of glucose is zero, since glucose is completely reabsorbed in the renal tubules and not excreted. Glycosuria – the excretion of glucose into the urine- is nearly always caused by elevated blood glucose levels, most commonly due to untreated diabetes mellitus.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 129
Incorrect
-
A 12-year old girl was brought to the hospital with recurrent headaches for 6 months. Her physical examination revealed no abnormality. A CT scan of the head revealed a suprasellar mass with calcifications, eroding the surrounding sella turcica. The lesion is likely to represent:
Your Answer:
Correct Answer: Craniopharyngioma
Explanation:Craniopharyngiomas (also known as Rathke pouch tumours, adamantinomas or hypophyseal duct tumours) affect children mainly between the age of 5 and 10 years. It constitutes 9% of brain tumours affecting the paediatric population. These are slow-growing tumours which can also be cystic, and arise from the pituitary stalk, specifically the nests of epithelium derived from Rathke’s pouch. Histologically, this tumour shows nests of squamous epithelium which is lined on the outside by radially arranged cells. Calcium deposition is often seen with a papillary type of architecture.
ACTH-secreting pituitary adenomas are rare and mostly microadenomas. Paediatric astrocytoma’s usually occur in the posterior fossa. Although null cell adenomas can cause mass effect and give rise to the described symptoms, they are not suprasellar. Prolactinomas can also show symptoms of headache and disturbances in the visual field, however they are known to be small and slow-growing.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 130
Incorrect
-
A victim of mob justice was brought to the A & E with a stab wound in the anterior chest 2 cm lateral to the left sternal border. He underwent an emergency thoracotomy that revealed clots in the pericardium, with a puncture wound in the right ventricle. To evacuate the clots from the pericardial cavity the surgeon slipped his hand behind the heart at its apex. He extended his finger upwards until its tip was stopped by a line of pericardial reflection which forms the:
Your Answer:
Correct Answer: Oblique pericardial sinus
Explanation:Transverse sinus: part of pericardial cavity that is behind the aorta and pulmonary trunk and in front of the superior vena cava separating the outflow vessels from the inflow vessels.
Oblique pericardial sinus: is behind the left atrium where the visceral pericardium reflects onto the pulmonary veins and the inferior vena cava. Sliding a finger under the heart will take you to this space.
Cardiac notch: indentation of the ‘of the heart’ on the superior lobe of the left lung.
Hilar reflection: the reflection of the pleura onto the root of the lung to continue as mediastinal pleura.
Costomediastinal recess: part of the pleural sac where the costal pleura transitions to become the mediastinal pleura.
Sulcus terminalis: a groove between the right atrium and the vena cava
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 131
Incorrect
-
Blood investigations of a patient with vitamin K deficiency revealed a prolonged prothrombin time. This coagulation abnormality is most probably due to:
Your Answer:
Correct Answer: Factor VII deficiency
Explanation:Factor VII deficiency is a bleeding disorder caused by a deficiency or reduced activity of clotting factor VII. It may be inherited or acquired at some point during life. Inherited factor VII deficiency is an autosomal recessive disorder caused by mutations of the F7 gene. Factor VII is vitamin K-dependent, as are Factors II, IX and X and therefore lack of this vitamin can cause the development of acquired factor VII deficiency. Other causes of acquired deficiency of this factor include liver disease, sepsis and warfarin therapy.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 132
Incorrect
-
A 47 -year-old male was admitted due to a bleeding peptic ulcer. On his 3rd hospital day, he developed a cardiac arrhythmia. His serum potassium was markedly elevated. What is the most likely cause of hyperkalaemia in this patient?
Your Answer:
Correct Answer: Multiple blood transfusions
Explanation:Patients with gastrointestinal bleeding often require blood transfusion. Among the various side effects of blood transfusions, is the increase of potassium levels. The use of stored blood for transfusions is followed by an increase of serum potassium levels. Potassium level increases are more pronounced in patients who receive blood stored for more than 12 d. Furthermore, the lysis and destruction of red blood cells, especially in the transfusion of older PRBCs, can further increase potassium levels. Excessive use of a PPi has been associated with hyperkaelemia however would be less likely in this acute setting.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 133
Incorrect
-
A 27-year-old woman has chronic low serum calcium levels. Which of the following conditions may be responsible for the hypocalcaemia in this patient?
Your Answer:
Correct Answer: Hypoparathyroidism
Explanation:Chronic hypocalcaemia is mostly seen in patients with hypoparathyroidism as a result of accidental removal or damage to parathyroid glands during thyroidectomy.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 134
Incorrect
-
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:
Correct 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.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 135
Incorrect
-
An old man presented with atrophy of the thenar eminence despite the sensation over it still being intact. What is the injured nerve in this case?
Your Answer:
Correct Answer: Median nerve
Explanation:Atrophy of the thenar muscles means injury to the motor supply of these muscles. The nerve that sends innervation to it is the median nerve. But the median nerve does not provide sensory innervation to the overlying skin so sensation is spared.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 136
Incorrect
-
A 58-year-old woman presents with signs of inflammation in the first metatarsophalangeal joint: redness, swelling and pain. The analysis of synovial fluid reveals needle-shaped, strongly negatively birefringent crystals. What's the most likely diagnosis in this case?
Your Answer:
Correct Answer: Gout
Explanation:Gout is a rheumatic disease caused by the precipitation of monosodium urate crystals into tissues, usually joints. This causes acute or chronic pain; the acute illness initially affects only one joint, often the first metatarsophalangeal joint. The diagnosis of the disease requires the identification of crystal in the synovial fluid. These crystals are needle-shaped and strongly negatively birefringent.
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 137
Incorrect
-
A 5-year-old child is rushed to the emergency department because of fever, erythema and neck stiffness. The child is also hypotensive upon physical examination. Which is the most likely toxin responsible for this child's condition?
Your Answer:
Correct Answer: Endotoxin
Explanation:An endotoxin is part of the bacterial outer membrane, and it is not released until the bacterium is killed by the immune system. The body’s response to an endotoxin can involve severe inflammation. In general, the inflammation process is usually considered beneficial to the infected host, but if the reaction is severe enough, it can lead to sepsis.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 138
Incorrect
-
When exposing the right saphenofemoral junction for flush-ligation of the saphenous vein, which of the following is the most likely to be seen passing through this opening?
Your Answer:
Correct Answer: Superficial external pudendal artery
Explanation:The saphenous opening is an oval opening in the fascia lata. It is covered by the cribriform fascia and It is so called because it is perforated by the great saphenous vein and by numerous blood and lymphatic vessels and the superficial external pudendal artery pierces it.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 139
Incorrect
-
A previously healthy 40-year-old housewife suddenly complains of a headache and loses consciousness. A CT scan reveals subarachnoid haemorrhage. Which of the following is the most probable cause?
Your Answer:
Correct Answer: Ruptured berry aneurysm
Explanation:Saccular aneurysms, also known as berry aneurysms, appear as a round outpouching and are the most common form of cerebral aneurysm. They are a congenital intracranial defect, and haemorrhage can occur at any age, but is most common between the ages of 40-65 years. A second rupture (rebleeding) sometimes occurs, most often within about 7 days of the first bleed.
-
This question is part of the following fields:
- Neurology
- Pathology
-
-
Question 140
Incorrect
-
A 25 year-old male patient was brought to the hospital due to a vehicular accident. A skull x-ray was done which revealed a fracture along the base of the middle cranial fossa. The patient has no sense of touch over the skin over his cheek and chin. Injury to the maxillary and the mandibular nerves is suspected. In which foramina do these two affected sensory branches leave the cranial cavity.
Your Answer:
Correct Answer: Foramen rotundum and foramen ovale
Explanation:The patient’s clinical manifestations suggests an injury to the maxillary and mandibular nerves. The maxillary branch (V2) of the trigeminal nerve (CN V) passes through and exits the skull via the pterygopalatine fossa and the foramen rotundum. At the base of the skull the foramen ovale (Latin: oval window) is one of the larger of the several holes (the foramina) that transmit nerves through the skull. The foramen ovale is situated in the posterior part of the sphenoid bone, posterolateral to the foramen rotundum. The following structures pass through foramen ovale: mandibular nerve, motor root of the trigeminal nerve, accessory meningeal artery (small meningeal or paradural branch, sometimes derived from the middle meningeal artery), lesser petrosal nerve, a branch of the glossopharyngeal nerve and an emissary vein connecting the cavernous sinus with the pterygoid plexus of veins. Occasionally it will also carry the anterior trunk of the middle meningeal vein.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 141
Incorrect
-
Which of the following is a true statement regarding the pupil?
Your Answer:
Correct Answer: Phentolamine causes pupil constriction
Explanation:A balance between the sympathetic tone to the radial fibres of the iris and parasympathetic tone to the pupillary sphincter muscle determines the pupil size. Phentolamine (α-adrenergic receptor blocker) causes pupillary constriction. Dilatation of the pupil occurs with increased sympathetic activity, decreased parasympathetic activity during darkness or block of muscarinic receptors by atropine.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 142
Incorrect
-
What is the basic chemical reaction that takes place in the breakdown of complex foodstuffs?
Your Answer:
Correct Answer: Hydrolysis
Explanation:Breakdown of complex food into simpler compounds is achieved by hydrolysis, with the help of different enzymes specific for different compounds.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 143
Incorrect
-
The thyroid gland is a large ductless gland located in which part of the neck?
Your Answer:
Correct Answer: Visceral space
Explanation:The thyroid gland is an endocrine gland in the neck, consisting of two lobes connected by an isthmus. It is situated at the front and sides of the neck in the visceral space.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 144
Incorrect
-
Epstein-Barr virus (EBV) is known to be a carcinogen for:
Your Answer:
Correct Answer: B-cell lymphoma
Explanation:EBV is known to be carcinogenic for B-cell lymphoma, nasopharyngel carcinoma and Hodgkin’s lymphoma.
-
This question is part of the following fields:
- Microbiology; Neoplasia
- Pathology
-
-
Question 145
Incorrect
-
A 55-year-old woman complains of pain in the proximal and distal interphalangeal joins, and back pain which has increased over the last 4 years and worsens after activity. X-rays reveal Heberden’s and Bouchard’s nodes in her interphalangeal joints and the presence of osteophytes in her spine. What is the most likely diagnosis?
Your Answer:
Correct Answer: Osteoarthritis
Explanation:Osteoarthritis is most common in older adults, predominating in women between the ages of 40 and 70; after this age, men and women are affected equally. It affects an entire joint, with disruption and potential loss of joint cartilage, along with other joint changes, including bone hypertrophy (osteophyte formation). The pain is usually gradual and is worse after activity, with occasional joint swelling. X-ray findings include marginal osteophytes, narrowing of the joint space, increased density of the subchondral bone, subchondral cyst formation, bony remodelling and joint effusions.
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 146
Incorrect
-
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:
Correct 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.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 147
Incorrect
-
A 27-year-old woman, who had been taking a combined oral contraceptive for 6 months, presented with inguinal pain and oedema of the left leg. Which of the following investigations would you recommend to help confirm the diagnosis?
Your Answer:
Correct Answer: Duplex scan
Explanation:Oral combined contraceptive pill (OCCP) is a drug used for birth control and treating a number of other conditions. Women who take the OCP have a higher risk of developing deep vein thrombosis (DVT), usually in the legs. Duplex ultrasonography is a safe and non-invasive technique which is used for diagnosing the presence of lower extremity thrombi.
-
This question is part of the following fields:
- Cardiovascular
- Pathology
-
-
Question 148
Incorrect
-
What percentage of the cardiac output is delivered to the brain?
Your Answer:
Correct 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%.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 149
Incorrect
-
An intern is attempting to put in an arterial line in an ICU patients left foot. Which is the best site to feel for the pulsation of the dorsalis pedis artery in the foot?
Your Answer:
Correct Answer: Just lateral to the tendon of extensor hallucis longus
Explanation:The dorsalis pedis artery is the continuation of the anterior tibial artery. The pulse of the posterior tibial artery, which comes from the posterior compartment of the leg, may be felt behind the medial malleolus just lateral to the tendon of the extensor hallucis longus.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 150
Incorrect
-
A blood sample of a 58 year old male patient, who underwent an abdominal aortic aneurysm repair, was sent to the laboratory. The laboratory technician said that the patient’s blood agglutinates with antisera anti-A and anti-D, while the patient’s serum agglutinates cells of blood group B. What is the blood group of this patient?
Your Answer:
Correct Answer: A positive
Explanation:Group A – has only the A antigen on red cells (and B antibody in the plasma)
Group B – has only the B antigen on red cells (and A antibody in the plasma)
Group AB – has both A and B antigens on red cells (but neither A nor B antibody in the plasma)
Group O – has neither A nor B antigens on red cells (but both A and B antibody are in the plasma). Many people also have a so-called Rh factor on the red blood cell’s surface. This is also an antigen and those who have it are called Rh+. A person with Rh– blood does not have Rh antibodies naturally in the blood plasma (as one can have A or B antibodies, for instance) but they can develop Rh antibodies in the blood plasma if they receive blood from a person with Rh+ blood, whose Rh antigens can trigger the production of Rh antibodies. A person with Rh+ blood can receive blood from a person with Rh– blood without any problems. In this scenario the person has blood group A+ as he has A antigen, anti B antibody and Rh antigen
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 151
Incorrect
-
A 40-year old gentleman underwent a computed tomographic scan for the abdomen to rule out blunt abdominal trauma, after a vehicular accident. The scan revealed no abnormal finding except for a 1 cm-sized cortical mass in the left adrenal gland. The doctor-on-call decided to not intervene for this mass because it was likely to be a:
Your Answer:
Correct Answer: Non-functioning adrenal adenoma
Explanation:Adrenal adenomas are common, benign lesions which are asymptomatic and seen in 10% of population. Usually detected incidentally on Computed tomography (‘incidentaloma’), only around 1 in 10,000 are malignant (adenocarcinoma). Adrenal adenomas rarely need to be investigated, especially if they are homogenous and less than 3 cm in diameter. Follow-up imaging can be done after an interval of 3-6 months to assess any change in size. Some adenomas can secrete cortisol (leading to Cushing syndrome), or aldosterone (leads to Conn syndrome) or androgens (leading to hyperandrogenism).
Haematomas and simple cysts are not usually seen in adrenal gland. Infection due to Histoplasma capsulatum is usually bilateral and leads to multiple granulomas. Adrenal metastasis will usually demonstrate a lung primary and the adrenal lesions will be often multiple and larger than 1 cm.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 152
Incorrect
-
A 40-year old Caucasian male came to the hospital with complaints of fatigue and lethargy. On examination, he was found to have raised blood pressure. Urine examination showed >300 mg/dl proteinuria (4+) and 24-hour urine protein 3.5g. No glucose, blood, nitrites, urobilinogen or casts were present in urine. What is the most likely diagnosis?
Your Answer:
Correct Answer: Membranous glomerulonephritis
Explanation:Membranous glomerulonephritis or nephropathy, is a renal disorder with insidious course and usually affects people aged 30-50 years. 85% cases are primary (or idiopathic). The other 15% are secondary to autoimmune conditions like SLE, infections like malaria or hepatitis B, drugs like captopril and NSAIDs, or malignancies (particularly lung or colonic carcinoma). This disease is caused due to circulating immune complexes which are said to form by binding of antibodies to antigens in glomerular basement membrane. This antigens could be endogenous or derived from systemic circulation. This immune complex triggers the complement system, resulting in formation of membrane attack complex (MAC) on glomerular epithelial cells. This further results in release of proteases and oxidants which damage the capillaries making them ‘leaky’. Moreover, the epithelial cells also secrete a mediator to reduce nephron synthesis and distribution.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 153
Incorrect
-
The normal location of the major duodenal papilla:
Your Answer:
Correct Answer: Descending part of the duodenum
Explanation:The major duodenal papilla is on the descending portion of the duodenum on the medial side, about 7-10cm from the pylorus. The pancreatic ducts and the common bile ducts unite and open by a common orifice on the summit of the duodenal papilla.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 154
Incorrect
-
A medical intern wanting to perform her first thoracentesis (remove fluid from the pleural cavity) wishes to be reminded where to insert the needle to aspirate in order to avoid injuring the lung or neurovascular elements. Where is this place?
Your Answer:
Correct Answer: The bottom of interspace 9 in the midaxillary line
Explanation:Thoracentesis is performed in the costodiaphragmatic recess. The needle needs to be inserted below the level of the lungs to avoid injury to the lungs. At the paravertebral line, is between ribs 10 and 12, at the midaxillary line between ribs 8 and 10 and at the midclavicular line between interspaces 6 and 8. The needle should be inserted at the top of the rib (or the bottom of the interspace) to avoid damage to the neurovascular structures found below the rib running in the costal groove.
The recommended location for the needle insertion varies depending upon the source. It is critical that the patient hold his or her breath to avoid piercing of the lung.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 155
Incorrect
-
Which of the following is a fact worth noting about the development of the spleen?
Your Answer:
Correct Answer: It develops in the dorsal mesogastrium
Explanation:The spleen in the human embryo arises in week 5 of intrauterine life. It appears as a proliferating mesenchyme above the pancreas. The spleen is one the organs that develops in the dorsal mesogastrium. When the stomach changes its position during development, the spleen is made to move behind the stomach and stays in contact with the left kidney. The spleen is found within the peritoneum of the abdominal cavity thus it is an intraperitoneal organ.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 156
Incorrect
-
Which of the following two cerebral veins join up to form the great cerebral vein, otherwise also known as the great vein of Galen?
Your Answer:
Correct Answer: Internal cerebral veins
Explanation:The great vein of Galen or great cerebral vein, is formed by the union of the internal cerebral veins and the basal veins of Rosenthal. This vein curves upwards and backwards along the border of the splenium of the corpus callosum and eventually drains into the inferior sagittal sinus and straight sinus at its anterior extremity.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 157
Incorrect
-
A man in his sixties underwent surgery to remove a lump from his axilla. During removal, a nerve originating from the lateral cord of the brachial plexus was damaged. Which nerve is this referring to?
Your Answer:
Correct Answer: Lateral pectoral
Explanation:The only branch of the lateral cord of brachial plexus in the options given, is the lateral pectoral nerve. It supplies the pectoralis major muscle and sends a branch to join the medial pectoral nerve forming a loop in front of the first part of the axillary artery.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 158
Incorrect
-
A football player sustained an injury to his ankle. The wound went through the skin, subcutaneous tissue and flexor retinaculum. Which other structure passing under the retinaculum may be injured?
Your Answer:
Correct Answer: Tibial nerve
Explanation:The flexor retinaculum is immediately posterior to the medial malleolus. The structures that pass under the flexor retinaculum from anterior to posterior are: tendon of the tibialis posterior, flexor digitorum longus, posterior tibial artery (and vein), tibial nerve and tendon of flexor hallucis longus. The tibial nerve is the only one which lies behind the flexor retinaculum.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 159
Incorrect
-
The following structures DO NOT lie between the layers of the mesosalpinx except for the?
Your Answer:
Correct Answer: Fallopian tube
Explanation:Mesosalpinx is the portion of the broad ligament that stretches from the fallopian tube to the ovary and contains the uterine tubes between it’s layers.
-
This question is part of the following fields:
- Anatomy
- Pelvis
-
-
Question 160
Incorrect
-
Which of the following factors will not affect the wound healing process in a young women who suffered serious burns to her chest and hands?
Your Answer:
Correct Answer: Vitamin A deficiency
Explanation:Healing can be sped-up or slowed down due to various reasons: 1. blood supply, 2. infection, 3. denervation, 4. collection of blood/hematoma, 5. mechanical stress, 6. foreign body, 7. techniques used during surgery and 8. dressing of the wound. Other systemic factors include 1. nutrition e.g. deficiency of zinc, vitamin C, protein deficiency, 2. metabolic status, 3. circulatory status and 4. hormonal influence
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 161
Incorrect
-
A 42 year old man presents with end stage renal failure and is prepared to receive a kidney from his best friend. HLA testing showed that they are not a 100% match and he is given immunosuppressant therapy for this. Three months later when his renal function is assessed, he showed signs of deteriorating renal function, with decreased renal output, proteinuria of +++ and RBCs in the urine. He was given antilymphocyte globulins and his condition reversed. During the crisis period the patient is likely to be suffering from?
Your Answer:
Correct Answer: Acute rejection
Explanation:This patients is most likely experiencing an acute rejection. It is a cell mediated attack against the organ that has been transplanted. Antigens are either presented by blood borne cells with in the graft or antigen presenting cells in the body may be presenting class I and class II molecules that have been shed by the graft. Class I will activate CD8 and class II, CD4 cells, both of which will attack the graft.
Chronic rejection is a slow process which occurs months to years after the transplant. The exact mechanism is not very well understood but it probably involves a combination of Type III and Type IV hypersensitivity directed against the foreign MHC molecules which look like self-MHC presenting a foreign antigen.
Hyperacute Transplant Rejection occurs almost immediately and is often evident while you are still in surgery. It is caused by accidental ABO Blood type mismatching of the donor and recipient which almost never happens anymore. This means the host has preformed antibodies against the donated tissue.
-
This question is part of the following fields:
- Inflammation & Immunology; Renal
- Pathology
-
-
Question 162
Incorrect
-
Which of the following structures lying posterior to the ovary are at risk of injury in excision of a malignant tumour in the right ovary?
Your Answer:
Correct Answer: Ureter
Explanation:The ovaries are two nodular structures situated one on either side of the uterus in relation to the lateral wall of the pelvis and attached to the back of the broad ligament of the uterus, lying posteroinferiorly to the fallopian tubes. Each ovary has a lateral and medial surface. The ureter is at greater risk of iatrogenic injury at this location.
-
This question is part of the following fields:
- Anatomy
- Pelvis
-
-
Question 163
Incorrect
-
During an operation for a sigmoid colectomy the surgeon ligates the sigmoid arteries. From which artery do the sigmoid arteries branch?
Your Answer:
Correct Answer: Inferior mesenteric artery
Explanation:Sigmoid arteries are branches of the inferior mesenteric artery (IMA). Sigmoid artery gives off branches that supply the lower descending colon, the iliac colon and the sigmoid colon.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 164
Incorrect
-
A 29-year-old pregnant woman suffering from hyperemesis gravidarum is prescribed metoclopramide. What is the mechanism of action of metoclopramide?
Your Answer:
Correct Answer: Dopamine antagonist
Explanation:Metoclopramide is a potent dopamine-receptor antagonist with anti-emetic and prokinetic properties. It is therefore commonly used to treat nausea and vomiting, and to facilitate gastric emptying in patients with gastric stasis. The anti-emetic action of metoclopramide is due to its antagonist activity at D2 receptors in the chemoreceptor trigger zone (CTZ) in the central nervous system. Common adverse drug reactions associated with metoclopramide include restlessness (akathisia), and focal dystonia.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 165
Incorrect
-
A 65-year-old smoker presents with painless haematuria, urinary frequency and urgency. He is diagnosed with bladder cancer. Which is the most likely type?
Your Answer:
Correct Answer: Transitional cell carcinoma
Explanation:90% of bladder cancers are transitional cell carcinomas derived from the bladder urothelium. Risk factors include industrial chemicals, smoking and infection. Schistosomiasis and bladder stones predispose to the squamous cell variety.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 166
Incorrect
-
Digital rectal examination of a 75-year old gentleman who presented to the surgical clinic with urinary retention revealed an enlarged, nodular prostate. PSA was found to be elevated, favouring the diagnosis of prostatic malignancy. Which of the given options is the most common malignant lesion affecting the prostate gland?
Your Answer:
Correct Answer: Adenocarcinoma
Explanation:Prostatic adenocarcinoma is the commonest solid malignancy and non-dermatological cancer in men above 50 years age. Increasing in incidence with age and the highest risk seen in the black population. About 75% of cases are seen in men over 65 years. Other tumours affecting the prostate include undifferentiated prostate cancer, squamous cell carcinoma, and ductal transitional carcinoma, but these occur less commonly. Sarcomas usually affect children. Hormones play a role in the aetiology of prostate adenocarcinoma unlike the other types. Intraepithelial neoplasia is considered a precursor of invasive malignancy.
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 167
Incorrect
-
A 35-year-old woman is in a comatose state following a traumatic head injury, and is receiving intravenous (IV) antibiotics and IV fluids containing saline and 5% dextrose. A serum biochemistry analysis is performed five days later which shows a low serum potassium level. This is most likely to be due to:
Your Answer:
Correct Answer: Nothing per oral regimen
Explanation:In this patient the cause for hypokalaemia is insufficient consumption of potassium as she is nil-per mouth with no intravenous supplementation. Parenteral nutrition has been used for comatose patients, although enteral feeding is usually preferable, and less prone to complications.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 168
Incorrect
-
Carbon dioxide is principally transported in the blood in which form?
Your Answer:
Correct Answer: Bicarbonate
Explanation:Carbon dioxide is transported in the blood in various forms:
– Bicarbonate (80–90%)
– Carbamino compounds (5–10%)
– Physically dissolved in solution (5%).
Carbon dioxide is carried on the haemoglobin molecule as carbamino-haemoglobin; carboxyhaemoglobin is the combination of haemoglobin with carbon monoxide.
-
This question is part of the following fields:
- Physiology
- Respiratory; Cardiovascular
-
-
Question 169
Incorrect
-
A 40 year old man from Japan was diagnosed with cancer of the oesophagus. He is to undergo esophagectomy. While mobilizing the oesophagus in the neck, for resection and anastomosis with the stomach tube on the left side, the surgeon must be cautious not to injure a vital structure. Which of the following is it?
Your Answer:
Correct Answer: Thoracic duct
Explanation:The oesophagus is divided into 3 portions: cervical (part that is in the neck), thoracic portion and the abdominal portion. The cervical part is bordered by the trachea anteriorly and the prevertebral fascia covering the bodies of the 6,7 and 8th vertebra posteriorly. The thoracic duct lies on the left side at the level of the sixth cervical vertebra. The carotid sheath with its contents and lower poles of the lateral lobes of thyroid gland are lateral. The thoracic duct is the structure most likely to be injured.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 170
Incorrect
-
A medical student is asked to calculate the net pressure difference in a capillary wall, considering: Interstitial fluid hydrostatic pressure = –3 mmHg, Plasma colloid osmotic pressure = 28 mmHg, Capillary hydrostatic pressure = 17 mmHg, Interstitial fluid colloid osmotic pressure = 8 mmHg, and Filtration coefficient = 1. Which is the correct answer?
Your Answer:
Correct Answer: 0 mmHg
Explanation:The rate of filtration at any point along a capillary depends on a balance of forces sometimes called Starling’s forces after the physiologist who first described their operation in detail. The Starling principle of fluid exchange is key to understanding how plasma fluid (solvent) within the bloodstream (intravascular fluid) moves to the space outside the bloodstream (extravascular space). Fluid movement = k[(pc– pi)–(Πc– Πi)] where k = capillary filtration coefficient, pc = capillary hydrostatic pressure, pi= interstitial hydrostatic pressure, Πc = capillary colloid osmotic pressure, Πi = interstitial colloid osmotic pressure. Therefore: 1 × [capillary hydrostatic pressure (17) – interstitial fluid hydrostatic pressure (–3)] – [plasma colloid osmotic pressure (28) – interstitial fluid colloid osmotic pressure (8)] = 0 mmHg
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 171
Incorrect
-
A 40-year old lady presented to the hospital with fever and mental confusion for 1 week. On examination, she was found to have multiple petechiae all over her skin and mucosal surfaces. Blood investigations revealed low platelet count and raised urea and creatinine. A platelet transfusion was carried out, following which she succumbed to death. Autopsy revealed pink hyaline thrombi in myocardial arteries. What is the likely diagnosis?
Your Answer:
Correct Answer: Thrombotic thrombocytopenic purpura
Explanation:Hyaline thrombi are typically associated with thrombotic thrombocytopenic purpura (TTP), which is caused by non-immunological destruction of platelets. Platelet transfusion is contraindicated in TTP. Platelets and red blood cells also get damaged by loose strands of fibrin deposited in small vessels. Multiple organs start developing platelet-fibrin thrombi (bland thrombi with no vasculitis) typically at arteriocapillary junctions. This is known as ‘thrombotic microangiopathy’. Treatment consists of plasma exchange.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 172
Incorrect
-
Which of the following diseases is caused by intra-articular and/or extra-articular deposition of calcium pyrophosphate dihydrate (CPPD) crystals, due to unknown causes?
Your Answer:
Correct Answer: Pseudogout
Explanation:Pseudogout or chondrocalcinosis is a rheumatological disease caused by the accumulation of crystals of calcium pyrophosphate dihydrate (CPPD) in the connective tissues. It is frequently associated with other conditions, such as trauma, amyloidosis, gout, hyperparathyroidism and old age, which suggests that it is secondary to degenerative or metabolic changes in the tissues. The knee is the most commonly affected joint. It causes symptoms similar to those of rheumatoid arthritis or osteoarthritis.
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 173
Incorrect
-
Which of these nerves controls adduction of hand?
Your Answer:
Correct Answer: Ulnar nerve
Explanation:The adductors of the fingers are the palmer interossei. They are supplied by the ulnar nerve, which is a branch of the medical cord of the brachial plexus.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 174
Incorrect
-
A sudden loud sound is more likely to result in cochlear damage than a slowly developing loud sound. This is because:
Your Answer:
Correct Answer: There is a latent period before the attenuation reflex can occur
Explanation:On transmission of a loud sound into the central nervous system, an attenuation reflex occurs after a latent period of 40-80 ms. This reflex contracts the two muscles that pull malleus and stapes closer, developing a high degree of rigidity in the entire ossicular chain. This reduces the ossicular conduction of low frequency sounds to the cochlea by 30-40 decibels. In this way, the cochlea is protected from damage due to loud sounds (these are low frequency sounds) when they develop slowly.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 175
Incorrect
-
A 55-year old patient with signs and symptoms of internal haemorrhage was brought in for emergency surgery to control the bleeding. Angiography results revealed an advanced duodenal tumour that had perforated the blood vessel immediately behind the first part of the duodenum. Which of the following is the most likely blood vessel that was ruptured by the cancer?
Your Answer:
Correct Answer: Gastroduodenal artery
Explanation:The gastroduodenal artery is the artery that lies just behind the first portion of the duodenum. The gastroduodenal artery would be the most likely artery to be perforated by a cancer in this area. The perforation is as a result of the spillage of the acidic content of the chyme in the duodenum. All the other blood vessels in the list would less likely be affected by the gastric expellant from the duodenum. The coronary vein is located in the lesser curvature of the stomach. The inferior pancreaticoduodenal arcade is located inferiorly to the first part of the duodenum on the head of the pancreas. The hepatic artery proper is a branch of the common hepatic artery that is located superior to the first portion of the duodenum. The splenic vein arises from the spleen; it forms the portal vein by joining the superior mesenteric vein. It is laterally detached from the duodenum. Both the left gastric vein and the splenic vein are located superior to the first portion of the duodenum.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 176
Incorrect
-
Pain in the right upper quadrant of the abdomen on ingestion of a fatty meal is seen in a condition which involves which of the following substances?
Your Answer:
Correct Answer: Cholecystokinin
Explanation:The clinical scenario described here favours the presence of gallstones. During food ingestion, vagal discharges stimulate gallbladder contraction. Moreover, presence of fat and amino acids in the intestinal lumen stimulates the release of cholecystokinin (CCK) in the duodenum. This causes sustained gallbladder contraction and relaxation of the sphincter of Oddi. If gallstones are present, there will be inflammation in the gallbladder and CCK will aggravate it due to contractions.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 177
Incorrect
-
A patient at the time of her second delivery opted for a bilateral pudendal nerve block. In order to inject the anaesthetic agent near the pudendal nerve a anaesthetic consultant had to insert a finger into the vagina and press laterally to palpate which landmark?
Your Answer:
Correct Answer: Ischial spine
Explanation:The ischial spine is always palpated through the walls of the vagina when performing a transvaginal pudendal nerve block and can easily be palpated on the lateral wall of the vagina.
-
This question is part of the following fields:
- Anatomy
- Pelvis
-
-
Question 178
Incorrect
-
A patient is admitted to the ICU, and is prescribed tazobactam, amongst other drugs. What is the mechanism of action of tazobactam?
Your Answer:
Correct Answer: Inhibits beta-lactamase
Explanation:Tazobactam is a compound which inhibits the action of bacterial beta-lactamases. It is added to the extended-spectrum beta-lactam antibiotic piperacillin to broaden the spectrum of piperacillin by making it effective against organisms that express beta-lactamase and would normally degrade piperacillin.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 179
Incorrect
-
Which of the following over-the-counter drugs can cause a prolonged bleeding time?
Your Answer:
Correct Answer: Acetylsalicylic acid
Explanation:Acetylsalicylic acid, or aspirin, is a nonsteroidal anti-inflammatory drug that is widely used as an analgesic and antipyretic. Aspirin is as a cyclo-oxygenase inhibitor that leads to decreased prostaglandin production. Decreased platelet aggregation is another effect of this drug, achieved by long-lasting use of aspirin.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 180
Incorrect
-
The blood-brain barrier is a membrane that separates the circulating blood from the brain extracellular fluid in the central nervous system (CNS). Which of the following statements regarding the blood– brain barrier is CORRECT?
Your Answer:
Correct Answer: It breaks down in areas of brain that are infected
Explanation:The blood–brain barrier is a membrane that controls the passage of substances from the blood into the central nervous system. It is a physical barrier between the local blood vessels and most parts of the central nervous system and stops many substances from travelling across it. During meningitis, the blood–brain barrier may be disrupted. This disruption may increase the penetration of various substances (including either toxins or antibiotics) into the brain. A few regions in the brain, including the circumventricular organs, do not have a blood–brain barrier.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 181
Incorrect
-
An abdominal aortogram of a 59 year-old female with an abdominal aortic aneurysm shows occlusion of the inferior mesenteric artery. The patient, however, does not complain of any symptoms. Occlusion of the inferior mesenteric artery is rarely symptomatic because its territory is supplied by branches of the:
Your Answer:
Correct Answer: Middle colic artery
Explanation:The transverse colon is supplied by the middle colic artery which is a branch from the superior mesenteric artery. If the inferior mesenteric artery was occluded, branches from the middle colic may go to the marginal artery which supplies the descending colon, sigmoid colon and rectum.. Ileocolic and right colic arteries also branch from the superior mesenteric artery that supply the colon but the middle colic, which serves the more distal part of the colon is the better answer. The gastroduodenal artery branches off the common hepatic artery, which supplies part of the duodenum, pancreas and stomach. The splenic artery supplies the spleen, pancreas and curvature of the stomach.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 182
Incorrect
-
Which portion of the renal tubule absorbs amino acids and glucose?
Your Answer:
Correct Answer: Proximal convoluted tubule
Explanation:In relation to the morphology of the kidney as a whole, the convoluted segments of the proximal tubules are confined entirely to the renal cortex. Glucose, amino acids, inorganic phosphate and some other solutes are reabsorbed via secondary active transport in the proximal renal tubule through co-transport channels driven by the sodium gradient.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 183
Incorrect
-
What is the chief ligament preventing posterior sliding of the tibia on the femur ?
Your Answer:
Correct 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.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 184
Incorrect
-
During a surgical operation, whilst dissecting the mediastinal lymph nodes for a bronchogenic carcinoma of the right upper lobe bronchus, a patient's right sympathetic trunk is accidentally severed above the level of spinal nerve T1. Which function would be left intact in the affected region?
Your Answer:
Correct Answer: Voluntary muscle activity
Explanation:The sympathetic nervous system regulates vascular tone, dilation of pupils, arrector pili muscles, sweat production and visceral reflexes. Neurones that supply the voluntary muscles originate from the ventral horn of the spinal cord. If these nerves were thus damaged, these functions would be impaired. The sympathetic nervous system is not responsible for voluntary muscle activity.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 185
Incorrect
-
Dicloxacillin is an antibiotic; the subclass that dicloxacillin belongs to is:
Your Answer:
Correct Answer: Penicillin
Explanation:Dicloxacillin is a narrow-spectrum beta-lactam antibiotic. It is used to treat infections caused by susceptible Gram-positive bacteria and most effective against beta-lactamase-producing organisms such as Staphylococcus aureus. To decrease the development of resistance, dicloxacillin is recommended to treat infections that are suspected or proven to be caused by beta-lactamase-producing bacteria.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 186
Incorrect
-
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:
Correct 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.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 187
Incorrect
-
A 13-year-old girl has complained of pain in her left arm for 4 months. An X-ray reveals a mass along with erosion of the affected humerus. Histologically, the tumour is found to be formed by small, round, blue cells. What is the most likely diagnosis?
Your Answer:
Correct Answer: Ewing’s sarcoma
Explanation:Ewing’s sarcoma is formed by small, round, blue cells, and is common in children. The usually develop in limbs, and clinical findings include pain and inflammation, with lytic destruction showing up on X-rays.
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 188
Incorrect
-
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:
Correct 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.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 189
Incorrect
-
Lateral medullary syndrome, also known as Wallenberg's syndrome is a neurological condition caused by ischaemia in the lateral part of the medulla oblongata and is commonly associated with numerous neurological symptoms. Which of the following arteries when occluded leads to this condition?
Your Answer:
Correct Answer: Posterior inferior cerebellar
Explanation:The lateral medullary syndrome or Wallenberg’s disease is also known as posterior inferior cerebellar artery syndrome (PICA). This syndrome is a clinical manifestation of the occlusion of the posterior cerebellar artery that results in symptoms of infarction of the lateral medullary oblongata. Other arteries that contribute to blood flow in to this region such are the vertebral artery, superior middle cerebellar and inferior medullary arteries can also result to this syndrome when occluded.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 190
Incorrect
-
Which of the following statements regarding aqueous humour is correct?
Your Answer:
Correct Answer: Is the only source of nutrients for the lens of the eye
Explanation:The aqueous humour is a transparent, watery fluid similar to plasma, but containing low protein concentrations. It is secreted from the ciliary epithelium and fills both the anterior and the posterior chambers of the eye. It maintains the intraocular pressure and inflates the globe of the eye. It is this hydrostatic pressure which keeps the eyeball in a roughly spherical shape and keeps the walls of the eyeball taut. It provides nutrition (e.g. amino acids and glucose) for the avascular ocular tissues; posterior cornea, trabecular meshwork, lens, and anterior vitreous. It may serve to transport ascorbate into the anterior segment to act as an antioxidant agent. The presence of immunoglobulins indicate its role in immune response to defend against pathogens.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 191
Incorrect
-
What is the most likely cause of prolonged bleeding time in a 40 year old women admitted for a laparoscopic cholecystectomy?
Your Answer:
Correct Answer: Thrombocytopaenia
Explanation:Bleeding time is related to platelet function, thus a decrease in platelet function, as seen in thrombocytopenia, DIC and von Willebrand disease in which platelet aggregation is defective, leads to an increase in bleeding time. It is not affected by a decrease or deficiency of any other clotting factors. Aspirin and other COX inhibitors prolong bleeding time along with warfarin and heparin.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 192
Incorrect
-
If a tumour is found in both lobes of the prostate, without nodal involvement or metastases, a histological grade of G2 and elevated PSA, what is the overall prostatic cancer stage?
Your Answer:
Correct Answer: Stage II
Explanation:The AJCC uses the TNM, Gleason score and PSA levels to determine the overall stage of prostatic cancer. This staging is as follows:
Stage I: T1, N0, M0, Gleason score 6 or less, PSA less than 10; or T2a, N0, M0, Gleason score 6 or less, PSA less than 10
Stage IIa: T1, N0, M0, Gleason score of 7, PSA less than 20; or T1, N0, M0, Gleason score of 6 or less, PSA at least 10 but less than 20; or T2a or T2b, N0, M0, Gleason score of 7 or less, PSA less than 20
Stage IIb: T2c, N0, M0, any Gleason score, any PSA; or T1 or T2, N0, M0, any Gleason score PSA of 20 or more; or T1 or T2, N0, M0, Gleason score of 8 or higher, any PSA
Stage III: T3, N0, M0, any Gleason score, any PSA Stage IV: T4, N0, M0,any Gleason score, any PSA; or any T, N1, M0,any Gleason score, any PSA; or Any T, any N, M1, any Gleason score, any PSA.
The patient in this case has a T2 N0 M0 G2 tumour, meaning it belongs in stage II
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 193
Incorrect
-
Cranial nerve XII, the hypoglossal nerve, innervates which one of the following muscles in the list?
Your Answer:
Correct Answer: Hyoglossus
Explanation:The cranial nerve XII, hypoglossal nerve, innervates all the intrinsic and extrinsic muscles of the tongue except the palatoglossus. The muscles of the tongue innervated by this nerve include the extrinsic muscles; hyoglossus, styloglossus, genioglossus and the intrinsic muscles; superior longitudinal, inferior longitudinal, vertical and transverse muscles. The salpingopharyngeus, palatoglossus and the palatopharyngeus muscles are innervated by the vagus nerve. The stylopharyngeus muscle is innervated by the glossopharyngeal nerve (CN IX). The mylohyoid muscle is innervated by the inferior alveolar nerve, a branch of the mandibular nerve. Finally, the geniohyoid muscle is innervated by the olfactory nerve (CN I) via the hypoglossal nerve.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 194
Incorrect
-
A cerebellar tremor can be differentiated from a Parkinsonian tremor in that:
Your Answer:
Correct Answer: It only occurs during voluntary movements
Explanation:Cerebellar disease leads to intention tremors, which is absent at rest and appears at the onset of voluntary movements. In comparison, Parkinson’s tremor is present at rest. Frequency of tremor is a less reliable means to differentiate between the two as the oscillation amplitude of the tremor is not constant throughout a voluntary action.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 195
Incorrect
-
The circle of Willis is one of the cerebrovascular safeguards comprised of the left and the right posterior communicating artery. Which of the following arteries in the brain is connected to the posterior cerebral artery by these posterior communicating arteries?
Your Answer:
Correct Answer: Internal carotid artery
Explanation:The Circle of Willis is an anastomosis of cerebral arteries that are located at the base of the brain. The Circle of Willis is one of the important safeguards that ensure back up of blood supply to parts of the brain in case of any cerebrovascular accident. The Circle of Willis is made up of an anterior portion of arteries including; the anterior cerebral arteries. The anterior cerebral arteries are connected to the posterior portion of the circle of Willis by the anterior communicating artery. The posterior portion is made up of the posterior cerebral artery which branch off from the basilar artery. The posterior cerebral artery are connected to the anterior portion of the circle of Willis by the posterior communicating artery. The posterior communicating artery connects the posterior cerebral artery to the internal carotid artery. The circle of Willis receives blood supply from the left and right internal carotid arteries that continues as the middle cerebral artery and posteriorly from the two vertebral arteries that join to form the basilar artery.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 196
Incorrect
-
A 30-year old lady was admitted to the general surgical ward after a diagnosis of perforation of the first part of the duodenum that resulted from a long standing ulcer. If this perforation led to the expulsion of the gastric content that resulted to the erosion of an artery found in this part of the duodenum (the posterior of the first part of the duodenum). Which of the following arteries is this most likely to be?
Your Answer:
Correct Answer: Gastroduodenal
Explanation:The proximal part of the duodenum is supplied by the gastroduodenal artery. This artery is found descending behind the first part of the duodenum after branching from the hepatic artery. If gastric content was to be expelled in the posterior portion of the first part of the duodenum, then this artery would be most likely to be damaged. The common hepatic artery and the left gastric artery are branches of the coeliac trunk that are found superior to the duodenum. The proper hepatic artery is a branch of the common hepatic artery also found superior to the duodenum. The superior mesenteric artery is found behind the pancreas as a branch of the aorta that is at the bottom of the L1 level. The right gastric artery arises above the pylorus from the proper hepatic artery and supplies the lesser curvature of the stomach. The intestinal arteries supply the ileum and the jejunum.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 197
Incorrect
-
A 27-year-old female was admitted due to severe dehydration. The patient also complained of chest tightness, thus an ECG was requested. The ECG strip showed an isoelectric ST segment, upright T wave, with prominent U waves. What is the most likely electrolyte abnormality responsible for these ECG tracing?
Your Answer:
Correct Answer: Hypokalaemia
Explanation:U waves are prominent if it is >1-2mm or 25% of the height of the T wave. Abnormally prominent U waves are characteristically seen in severe hypokalaemia.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 198
Incorrect
-
A neonate is diagnosed with cryptorchidism of the right side (undescended testis). Which is the LEAST likely place to find the testis?
Your Answer:
Correct Answer: Perineum
Explanation:Embryologically the testes are retroperitoneal structures in the posterior abdominal wall, attached to the anterolateral abdominal wall by the gubernaculum. The gubernaculum ‘pulls’ the testes through the deep inguinal ring, inguinal canal and superficial inguinal ring and over the pelvic brim. The gubernaculum is preceded by the processus vaginalis that is derived from the peritoneum anterior to the testes. The processus vaginalis pushes the muscle and fascial layers. These eventually make up the canal and the spermatic cord, into the scrotum. The gubernaculum persists as the scrotal ligament while part of the processus vaginalis remains as a bursa-like sac i.e. the tunica vaginalis testes. The testes therefore could be caught in any one of these places along its path of descending. The testes are never in the perineum.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 199
Incorrect
-
During an operation to repair an aortic coarctation in a neonate, a surgeon accidentally cuts the first aortic intercostal arteries as he mobilised the descending aorta. Which one of the following structure might be deprived of its primary source of blood supply following this injury?
Your Answer:
Correct Answer: Right bronchus
Explanation:The right bronchus is supplied by one right bronchial artery that may branch from one of the left bronchial arteries or from the right 3rd posterior intercostal artery (this is the first intercostal artery that arises from the aorta). Damage to this artery might stop blood supply to the main bronchus. Intercostal arteries that go to the first and the second interspaces originate from the highest intercostal artery such that blood supply to either of these spaces would not be interfered with.
The left bronchus receives blood from 2 left bronchial arteries which are direct branches from the descending aorta.
Fibrous pericardium is the sac that contains the heart. Its blood supply is not a major concern.
Visceral pericardium receives its blood supply from the coronary vessels.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 200
Incorrect
-
Which of the following enzymes is secreted by the small intestinal mucosa?
Your Answer:
Correct Answer: Lactase
Explanation:Lactase, an enzyme belonging to β-galactosidase family of enzymes, brings about the hydrolysis of the disaccharide lactose into galactose and glucose. In humans, it is present along the brush border membrane of the cells lining the small intestinal villi. Deficiency of lactase causes lactose intolerance.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
