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Question 1
Correct
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Which of the following tumours has the best prognosis following surgery?
Your Answer: Schwannoma
Explanation:Schwannomas are histologically benign neoplasms that arise from nerve sheaths, most commonly from sensory nerve roots. They are generally contained within a capsule, and so can be surgically removed without injuring the associated nerve root. They are histologically benign and less than 1% become malignant.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 2
Correct
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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.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 3
Correct
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Regarding the extensor retinaculum of the wrist, which of these is CORRECT?
Your Answer: It prevents the tendons of the posterior compartment of the forearm from ‘bowstringing’ when the hand is extended at the wrist
Explanation:This extensor retinaculum, as the name indicates, holds the tendons of the extensors against the dorsal surface of the distal radius and ulna. Therefore, the correct answer is that it prevents bowstringing of the extensor tendons with wrist extension. It forms compartments between it and its bony attachment, and these compartments guide and hold the tendons.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 4
Correct
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Which of the following is a true statement regarding the pupil?
Your 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.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 5
Correct
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Which of the following clinical signs will be demonstrated in a case of Brown-Séquard syndrome due to hemisection of the spinal cord at mid-thoracic level?
Your Answer: Ipsilateral spastic paralysis, ipsilateral loss of vibration and proprioception (position sense) and contralateral loss of pain and temperature sensation beginning one or two segments below the lesion
Explanation:Brown–Séquard syndrome results due to lateral hemisection of the spinal cord and results in a loss of motricity (paralysis and ataxia) and sensation. The hemisection of the cord results in a lesion of each of the three main neural systems: the principal upper motor neurone pathway of the corticospinal tract, one or both dorsal columns and the spinothalamic tract. As a result of the injury to these three main brain pathways the patient will present with three lesions. The corticospinal lesion produces spastic paralysis on the same side of the body (the loss of moderation by the upper motor neurons). The lesion to fasciculus gracilis or fasciculus cuneatus results in ipsilateral loss of vibration and proprioception (position sense). The loss of the spinothalamic tract leads to pain and temperature sensation being lost from the contralateral side beginning one or two segments below the lesion. At the lesion site, all sensory modalities are lost on the same side, and an ipsilateral flaccid paralysis.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 6
Correct
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A 32-year old gentleman came to the emergency department, complaining of progressively increasing weakness in his arms and legs over 5 days. On examination, there is symmetrical weakness on both sides of his face, along with weakness of the proximal and distal muscles of all four limbs. No loss of sensation noted. Deep tendon reflexes could not be elicited and plantar responses were downward. On enquiry, it was revealed that he had an upper respiratory tract infection 10 days ago. The likely diagnosis is:
Your Answer: Guillain–Barré syndrome
Explanation:Guillain–Barré syndrome (GBS) is an acute, autoimmune polyradiculoneuropathy which affects the peripheral nervous system and is usually triggered by an acute infectious process. 75% patients have a history of acute infection within the past 1–4 weeks, usually respiratory or gastrointestinal. immunisations have also been implicated. The most common form is acute inflammatory demyelinating polyneuropathy. It results in an ascending paralysis with complete loss of deep tendon reflexes. Treatment includes immunoglobulins and supportive care. However, the disease may be fatal due to severe pulmonary complications and dysautonomia.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 7
Correct
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If a 55-year old gentleman who has suffered a stroke, develops a tremor in his fingers that worsens on reaching for an object, what part of his brain is likely to be involved?
Your Answer: Cerebellum
Explanation:The cerebellum plays an important role in the integration of sensory perception and motor output. Multiple neural pathways link the cerebellum with the motor cortex and the spinocerebellar tract. The cerebellum uses the constant feedback on body position to fine-tune the movements and integrates these pathways. The patient described here has a characteristic cerebellar tremor that is a slow, broad tremor of the extremities and occurs at the end of a purposeful movement.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 8
Correct
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When one is silently counting, what part of his brain will show increased regional cerebral blood flow (rCBF)?
Your 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.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 9
Correct
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Which of the following diseases causes abrupt vertigo, nausea, vomiting, tinnitus, and nystagmus?
Your Answer: Vestibular neuronitis
Explanation:Vestibular neuronitis or labyrinthitis causes a self-limited episode of vertigo, presumably due to inflammation of the vestibular division of cranial nerve VIII. Its causes are unknown, It may be due to a virus, but it can be related to a bacterial infection, head injury, stress, allergy, or as a reaction to medication. Symptoms can last up to 7-10 days.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 10
Correct
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Which of these infectious agents tends to affect people under 20 and over 40 years old, can cause acute encephalitis with cerebral oedema and petechial haemorrhages, along with haemorrhagic lesions of the temporal lobe. A lumbar puncture will reveal clear cerebrospinal fluid with an elevated lymphocyte count?
Your Answer: Herpes simplex virus
Explanation:Haemorrhagic lesions of the temporal lobe are typical of Herpes simplex encephalitis (HSE). It tends to affect patients aged under 20 or over 40 years, and is often fatal if left untreated. In acute encephalitis, cerebral oedema and petechial haemorrhages occur and direct viral invasion of the brain usually damages neurones. The majority of cases of herpes encephalitis are caused by herpes simplex virus-1 (HSV-1), and about 10% of cases of herpes encephalitis are due to HSV-2, which is typically spread through sexual contact.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 11
Correct
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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.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 12
Correct
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A patient in the recovery ward after cardiac surgery is noticed to have a small effusion in the lowest extent of the pleural cavity, into which no lung tissue extends. What is the name of this part of the pleural cavity?
Your Answer: Costodiaphragmatic recess
Explanation:The costodiaphragmatic recess is the part of the pleural cavity where the costal pleura is in continuity with the diaphragmatic pleura. It forms the lowest extent of the pleural cavity.
Costomediastinal recess: a tiny recess that is anteriorly located, where the costal pleura becomes continuous with the mediastinal pleura.
The cupola is the pleural cavity that extends above the first rib.
The inferior mediastinum refers to the posterior, middle and anterior mediastinal divisions together.
The pulmonary ligament on the other hand, is a pleural fold that is situated beneath the root of the lung on the medial aspect of the lung.
Oblique pericardial sinus is not part of the pleural cavity.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 13
Correct
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A 70-year-old man suffers an ischaemic stroke and develops a left homonymous hemianopia. Where is the likely infarct?
Your Answer: Right occipital lobe
Explanation:The man has a left homonymous hemianopia which means he is unable to view objects in the left visual field. This information is processed by the right primary visual cortex which lies in the right occipital lobe.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 14
Correct
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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.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 15
Incorrect
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An old woman complains of a lack of sensation halfway down the anterior surface of the thigh. The cause of this:
Your Answer: Would result from damage to a nerve accompanying the artery in the adductor canal
Correct Answer: Would result from damage to the nerve that innervates the pectineus muscle
Explanation:The pectineus is supplied by the second, third and fourth lumbar nerves through the femoral nerve and by the third lumbar through the accessory obturator when it exists. The anterior surface of the thigh receives its innervation from the femoral nerve as well, thus this is the nerve most likely to be injured
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 16
Correct
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Dysarthria, nystagmus and a tremor worsening with directed movement are likely to be seen in:
Your Answer: Cerebellar disease
Explanation:The given symptoms are seen in diseases affecting the cerebellum. A cerebellar tremor is a slow tremor that occurs at the end of a purposeful movement. It is seen in cerebellar disease, such as multiple sclerosis or some inherited degenerative disorders and chronic alcoholism. Classically, tremors are produced in the same side of the body as a one-sided lesion. Cerebellar disease can also result in a wing-beating’ type of tremor called rubral or Holmes’ tremor – a combination of rest, action and postural tremors. Other signs of cerebellar disease include dysarthria (speech problems), nystagmus (rapid, involuntary rolling of the eyes), gait problems and postural tremor of the trunk and neck.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 17
Incorrect
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A sudden loud sound is more likely to result in cochlear damage than a slowly developing loud sound. This is because:
Your Answer: A sudden sound carries more energy
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.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 18
Correct
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A young man came to the emergency room after an accident. The anterior surface of his wrist was lacerated with loss of sensation over the thumb side of his palm. Which nerves have been damaged?
Your Answer: Median
Explanation:The median nerve provides cutaneous innervation to the skin of the palmar radial three and a half fingers. Also the site of injury indicates that the medial nerve may have been injured as it passes into the hand by crossing over the anterior wrist.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 19
Correct
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A 50 year old male point was diagnosed with tennis elbow that became worse after he started playing basket ball over the last three months. He was admitted to the orthopaedic ward to have elbow braces fitted. What type of synovial joint is the elbow joint?
Your Answer: Hinge
Explanation:The elbow joint is one of the many synovial joints in the body. This joint is an example of the hinge joint as the humerus is received into the semilunar notch of the ulna and the capitulum of the humerus articulates with the fovea on the head of the radius, together acting as a hinge in one plane.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 20
Incorrect
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A patient presents with loss of pain and temperature sensation in the left leg. He is likely to have a lesion involving:
Your Answer: Left corticospinal tract
Correct Answer: Right lateral spinothalamic tract
Explanation:The spinothalamic tract is a sensory pathway originating in the spinal cord that transmits information to the thalamus. There are two main parts of the spinothalamic tract: the lateral spinothalamic tract transmits pain and temperature and the anterior spinothalamic tract transmits touch (crude touch). The decussation of this pathway occurs at the level of the spinal cord. Hence, a unilateral lesion of the lateral spinothalamic tract causes contralateral loss of pain and temperature.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 21
Correct
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A 50-year old gentleman who suffered a stroke was brought to the emergency department by his relatives. The patient however denied the presence of paralysis of his left upper and lower limbs. What is the most likely site of the lesion in this patient?
Your Answer: Right posterior parietal cortex
Explanation:A large injury to the non-dominant parietal cortex can make the patient neglect or refuse to acknowledge the presence of paralysis on the contralateral side. This can also involve the perception of the external world. Smaller injuries in this area which involve the precentral gyrus (primary motor cortex) or postcentral gyrus (primary sensory cortex) cause contralateral spastic paralysis or contralateral loss of tactile sensation respectively. A lesion in posterior inferior gyrus of the dominant frontal lobe results in motor aphasia. Involvement of the posterior superior gyrus of the dominant frontal lobe produces sensory aphasia.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 22
Correct
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After a car accident, a 30-year-old woman is alert and only has minor, superficial injuries. 2 hours later, she becomes unconscious and a CT scan reveals a convex, lens-shaped haemorrhage over the right parietal region. The most likely diagnosis is:
Your Answer: Epidural haematoma
Explanation:Epidural haematomas are usually caused by arterial bleeding, classically due to damage to the middle meningeal artery by a temporal bone fracture. Symptoms develop within minutes to several hours after the injury and consist of increasing headache, decreased level of consciousness, hemiparesis and pupillary dilation with loss of light reactivity. Around 15–20% of epidural hematomas are fatal.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 23
Correct
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The normal location of the major duodenal papilla:
Your 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.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 24
Correct
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A 34-year-old woman has been suffering from headaches, fever, vomiting, and confusion for the last 5 days. A CT scan reveals an oedematous mass with ring enhancement in the left temporal region. It is biopsied, revealing glial cells, necrosis, neutrophils and lymphocytes. What is the most likely diagnosis?
Your Answer: Cerebral abscess
Explanation:A cerebral abscess can result from direct extension of cranial infections, penetrating head trauma, haematogenous spread, or for unknown causes. An abscess forms when an area of cerebral inflammation becomes necrotic and encapsulated by glial cells and fibroblasts. Oedema around the abscess can increase the intracranial pressure. Symptoms result from increased intracranial pressure and mass effects. It is most frequent in the third decade of life, and when it occurs in children, it is usually associated with congenital heart disease.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 25
Correct
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A 39-year old female patient was diagnosed with a tumour of the left adrenal gland. The tumour, which is metastasizing to the adjacent tissues, has already extended to the left suprarenal vein. If the tumour is still spreading, which of the following veins will most likely be affected after the involvement of the left suprarenal vein?
Your Answer: Left renal vein
Explanation:The suprarenal veins or also known as the veins of Warshaw, are the veins that receive blood from the suprarenal glands. These veins receive blood from the medullary venous plexus and the cortex of the adrenal glands (suprarenal glands). They are two in number – the left and the right suprarenal veins. The right suprarenal vein drains into the inferior vena cava while the left suprarenal vein drains into the left renal vein. This therefore means that in the case of a metastasizing tumour involving the left suprarenal vein, the tumour will most likely extend from the left suprarenal vein to the left renal vein into which it drains.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 26
Incorrect
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Which is the correct statement regarding gonadal venous drainage:
Your Answer: The left testicular vein drains into the inferior vena cava
Correct Answer: The left ovarian vein drains into the left renal vein
Explanation:Spermatic or testicular veins arise from the posterior aspect of the testis and receive tributaries from the epididymis. Upon uniting, they form the pampiniform plexus that makes up the greater mass of the spermatic cord. The vessels that make up this plexus rise up the spermatic cord in front of the ductus deferens. They then unite, below the superficial ring, to form three or four veins that traverse the inguinal canal and enter the abdomen through the deep inguinal ring. They further unite to form 2 veins that ascend up the psoas major muscle behind the peritoneum each lying on either side of the testicular artery. These further unite to form one vein that empties on the right side of the inferior vena cava at an acute angle and on the left side into the renal vein, at a right angle. The left testicular vein courses behind the iliac colon and is thus exposed to pressure from the contents of this part of the bowel. The ovarian vein is the equivalent of the testicular vein in women. They form a plexus in the broad ligament near the ovary and uterine tube and communicate with the uterine plexus. They drain into similar vessels as in a man.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 27
Incorrect
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A surgeon performing a Whipple's procedure, that involves mobilizing the head of the pancreases, accidentally injured a structure immediately posterior to the neck of the pancrease which bled out. Which structure is most likely to have been injured?
Your Answer: Abdominal aorta
Correct Answer: Superior mesenteric artery
Explanation:The structure immediately posterior to the neck of the pancreas is the superior mesenteric vein. The neck of the pancreas lies anterior to the superior mesenteric vein, which joins with the splenic vein to form the portal vein.
The superior mesenteric artery (SMA) is also located in proximity to the neck of the pancreas. Specifically, the SMA emerges from the abdominal aorta just below the level of the pancreas and passes posterior to the neck of the pancreas before it descends into the mesentery to supply the intestines. Thus, both the superior mesenteric vein and the superior mesenteric artery are key vascular structures related to the posterior aspect of the neck of the pancreas.
Bleeding out would suggest an arterial injury.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 28
Correct
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A lesion involving the lateral geniculate nucleus of the thalamus is likely to affect:
Your Answer: Vision
Explanation:The lateral geniculate nucleus (LGN) of the thalamus is the primary processor of visual information in the central nervous system. The LGN receives information directly from the retina and sends projections directly to the primary visual cortex. The LGN likely helps the visual system focus its attention on the most important information.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 29
Correct
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A young man in a motor vehicle accident sustained a spinal injury at C8 level. What would likely be seen in this patient?
Your Answer: The hypothenar muscles would be completely paralysed
Explanation:The eighth cervical nerve is one of the contributors of the ulnar nerve. The ulnar nerve supplies the hypothenar muscles which include the opponens digiti minimi, abductor digiti minimi, flexor digiti minimi brevis, and palmaris brevis.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 30
Incorrect
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Which statement is true regarding the diaphragmatic openings:
Your Answer: The left phrenic nerve passes through the opening at T8
Correct Answer: The thoracic duct passes through the opening at T12
Explanation:The diaphragmatic openings are:
T8 – opening for the inferior vena cavaand the right phrenic nerve
T10 – opening for the oesophagusand the left gastric artery and vein
T12 – opening for the aorta, the thoracic duct and azygos vein.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 31
Incorrect
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A 16 year old girl fractured a bone in her left foot. Upon examination the clinician discovered that the fracture affected the insertion of the peroneus brevis muscle. Which of the following bones was most likely affected?
Your Answer: Base of the first metatarsal
Correct Answer: Base of the fifth metatarsal
Explanation:The peroneus brevis muscle originates from the lower two-thirds of the lateral body of the fibula and has inserts at the base of the fifth metatarsal. Fractures to this bone are common and can be due to infection, trauma, overuse and repetitive use.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 32
Incorrect
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A surgeon trainee is assisting in an operation to ligate the ductus arteriosus. The consultant supervising explains that caution is required when placing a clamp on the ductus to avoid injury to an important structure immediately dorsal to it. To which structure is the consultant referring?
Your Answer: Right Recurrent laryngeal nerve
Correct Answer: Left recurrent laryngeal nerve
Explanation:The left recurrent laryngeal nerve branches off the vagus and wraps around the aorta, posterior to the ductus arteriosus/ligamentum arteriosum from whence it courses superiorly to innervate the laryngeal muscles.
Accessory Hemiazygous vein is on the left side of the body draining the posterolateral chest wall and emptying blood into the azygos vein.
The left internal thoracic artery is branch of the left subclavian artery supplying blood to the anterior wall of the thorax.
Left phrenic nerve is lateral to the vagus nerve.
Thoracic duct: is behind the oesophagus, coursing between the aorta and the azygos vein in the posterior chest.
Right recurrent laryngeal nerve: loops around the right subclavian artery and is not in danger in this procedure.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 33
Incorrect
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Which structure holds the duodenojejunal flexure in place?
Your Answer: Hepatoduodenal ligament
Correct Answer: Suspensory ligament (of Treitz)
Explanation:The duodenum is connected to the diaphragm by the suspensory ligament called the ligament of Treitz. It is a slip of skeletal muscle from the right crus of the diaphragm and a fibromuscular band of smooth muscle from the 3rd and 4th parts of the duodenum. It is an important landmark, used to divide the gastrointestinal tract into the upper and lower parts. Contraction of this ‘ligament’ leads to opening of the duodenojejunal flexure allowing the flow of chyme.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 34
Correct
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Which muscle is most likely to be affected following an injury to the thoracodorsal nerve (C6-C8)?
Your Answer: Latissimus dorsi
Explanation:Latissimus dorsi is a triangular, flat muscle that covers the lumbar region and the lower half of the thoracic region. It is supplied by the sixth, seventh and eighth cervical nerves through the thoracodorsal (long subscapular) nerve.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 35
Incorrect
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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: Jejunum
Correct 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.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 36
Incorrect
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Production of pain is most likely associated with:
Your Answer: Gamma-aminobutyric acid (GABA)
Correct Answer: Substance P
Explanation:Substance P is a short-chain polypeptide that functions as a neurotransmitter and as a neuromodulator, and is thus, a neuropeptide. It has been linked with pain regulation, mood disorders, stress, reinforcement, neurogenesis, respiratory rhythm, neurotoxicity, nausea and emesis. It is also a potent vasodilator as it brings about release of nitric oxide from the endothelium. Its release can also cause hypotension.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 37
Incorrect
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During a procedure in the mediastinum, the surgeon accidentally injured a key structure that lies immediately anterior to the thoracic duct. Which structure is likely to be injured?
Your Answer: Azygos vein
Correct Answer: Oesophagus
Explanation:In the mid-thorax, the azygos vein, thoracic duct and aorta (in this order from right to the left) are all located posterior to the oesophagus. The superior vena cava, left internal jugular vein and trachea are not found in the mid thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 38
Correct
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A patient who following 20 years of working in the asbestos industry develops malignant mesothelioma and is scheduled for pleuropneumonectomy to remove the entire pleura and lung on the affected side. Which layer would provide a natural cleavage plane for surgical separation of the costal pleura from the thoracic wall?
Your Answer: Endothoracic fascia
Explanation:The endothoracic fascia is connective tissue that is between the costal parietal pleura and the inner aspect of the chest wall. Removing this layer of connective tissue would make it easy to separate the costal pleura from the thoracic wall.
Deep fascia: is not found around the lungs. It is a layer of connective tissue that invests a muscle or a group of muscles.
Parietal pleura: part of the pleura that lines the inner surface of the chest/thoracic cavity.
Visceral pleura: is the serous membrane that lines the surface of the lungs.
Transversus thoracis muscle fascia is associated only with the muscle transversus thoracis.
Peritracheal fascia: a layer of connective tissue that invests the trachea. It is not associated with the thoracic wall or the costal pleura.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 39
Incorrect
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A pedestrian sustained a left fibula fractured following a hit-and-run. X-rays showed that there was a transverse fracture of the upper end of the fibula. It was manifested clinically by inability to flex his foot at the ankle joint plus weak extension of the phalanges. What nerve is suspected to be injured in such a case?
Your Answer: Tibial
Correct Answer: Deep peroneal
Explanation:The deep peroneal nerve supplies the muscles allowing for flexion of the foot at the ankle joint, namely the tibialis anterior and peroneus tertius muscles. The peroneus tertius, peroneus brevis, and peroneus longus evert the foot, whereas the tibialis anterior and tibialis posterior invert the foot. Fibres of the deep peroneal nerve originate from L4, L5, and S1.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 40
Incorrect
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Rapid Eye Movement (REM) sleep is typically associated with:
Your Answer: Night terrors
Correct Answer: Penile erections
Explanation:Normal sleep comprises of alternate cycles between slow-wave sleep (non-REM sleep) and REM sleep. REM sleep is characterized by increased metabolic brain activity and EEG desynchronization. Somnambulism (sleepwalking), enuresis (bedwetting) and night terrors all occur during slow-wave sleep or during arousal from slow-wave sleep. In comparison, REM sleep is characterized by hypotonia of major muscle groups (excluding ocular muscles), dreams, nightmares and penile erection.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 41
Incorrect
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Which one of the following is a derivative of the midgut?
Your Answer: Biliary system
Correct Answer: Caecum
Explanation:The primary intestinal loop is formed from the midgut which gives rise to the distal half of the duodenum, the jejunum, ascending colon, proximal two thirds of the transverse colon and the ileum.
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This question is part of the following fields:
- Anatomy
- Embryology
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Question 42
Incorrect
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A 66-year-old man complains of constant headaches. On physical examination, the only relevant sign is a dark brown mole located on left his arm which has grown in size over the years and is itchy and painful. A MRI of the brain revealed a solitary lesion at the grey-white junction in the right frontal lobe, without ring enhancement. This lesion is most likely to be:
Your Answer: Viral inclusions
Correct Answer: Metastatic carcinoma
Explanation:The location of the mass at the grey–white junction is typical of a metastasis. The most frequent types of metastatic brain tumours originate in the lung, skin, kidney, breast and colon. These tumour cells reach the brain via the bloodstream. This patient is likely to have skin cancer, which caused the metastatic brain tumour.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 43
Correct
-
A surgeon ligates the left middle suprarenal artery while carrying out a left adrenalectomy. Where does the left middle suprarenal artery originate?
Your Answer: Abdominal aorta
Explanation:Middle suprarenal arteries arise from either side of the abdominal aorta, opposite the superior mesenteric artery.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 44
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.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 45
Correct
-
Destruction of the ventromedial nucleus of the hypothalamus will result in:
Your Answer: Loss of satiety
Explanation:The ventromedial nucleus of the hypothalamus is divided into an anterior and a superior part. The anterior part controls the female sexual drive, whereas the superior part is responsible for satiety. Destruction of the superior part of the nucleus will result in overeating, as no signal tells the body that it is satisfied.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 46
Incorrect
-
Which of the following will show decreased hearing when tested by air conduction but normal hearing when tested by bone conduction?
Your Answer: Destruction of the cochlea
Correct Answer: Fibrosis causing fixation of the ossicles
Explanation:As the cochlea is embedded into bone, the vibrations from the bone are transmitted directly to the fluid in the cochlea. Hence, any damage to the ossicles or tympanic membrane will not show an abnormal result on bone conduction test.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 47
Incorrect
-
A 28 year gang member was shot in the chest. The bullet hit a vessel that courses horizontally across the mediastinum. Which of the following vessels is it likely to be?
Your Answer: Right brachiocephalic vein
Correct Answer: Left brachiocephalic vein
Explanation:The superior vena cava that empties blood into the right atrium is formed by the right and the left brachiocephalic veins. Hence, the left brachiocephalic has to course across the mediastinum horizontally to join with its right ‘counterpart’. The left subclavian artery and vein being lateral to the mediastinum do not cross the mediastinum while the left jugular and the common carotid artery course vertically.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 48
Incorrect
-
A 68-year-old woman complains of headaches, dizziness, and memory loss. About a month ago, she fell from a staircase but only suffered mild head trauma. What is the most likely diagnosis in this case?
Your Answer: Cerebral contusion
Correct Answer: Chronic subdural haematoma
Explanation:A quarter to a half of patients with chronic subdural haematoma have no identifiable history of head trauma. If a patient does have a history of head trauma, it usually is mild. The average time between head trauma and chronic subdural haematoma diagnosis is 4–5 weeks. Symptoms include decreased level of consciousness, balance problems, cognitive dysfunction and memory loss, motor deficit (e.g. hemiparesis), headache or aphasia. Some patients present acutely. They usually result from tears in bridging veins which cross the subdural space, and may cause an increase in intracranial pressure (ICP).
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This question is part of the following fields:
- Neurology
- Pathology
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Question 49
Incorrect
-
The gluteus medius muscle:
Your Answer: Flexes the thigh at the hip joint
Correct Answer: Is supplied by the superior gluteal nerve
Explanation:The gluteus medius is situated on the outer surface of the pelvis. It arises from the outer surface of the ilium between the iliac crest and posterior gluteal line above and the anterior gluteal line below. The gluteus medius is supplied by the fourth and fifth lumbar and first sacral nerves through the superior gluteal nerve
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 50
Incorrect
-
An old man was diagnosed with squamous cell carcinoma with axillary lymph node metastasis. The doctor said he will excise the tumour and remove all axillary lymph nodes lateral to the edge of the pectoralis minor muscle. One of the following axillary lymph nodes won't be removed by this procedure. Which is it?
Your Answer: Subscapular
Correct Answer: Apical
Explanation:The apical lymph node group won’t be removed which include 20 to 30 lymph nodes.
Axillary lymph nodes are grouped according to location. The lateral group, the anterior to pectoral group, the posterior or subscapular group, the central group, and the medial or apical group. The lateral, pectoral, and subscapular groups are found lateral to the pectoralis minor muscle. The central group is situated directly under that muscle. Thus, if all lymph nodes lateral to the medial edge of the pectoralis minor muscle are removed, all the above four groups will be removed. The apical group won’t be removed which is situated medial to the medial edge of the pectoralis minor muscle.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 51
Incorrect
-
The muscle that forms the posterior wall of the axilla along with the scapula, subscapularis muscle and teres major muscle is the?
Your Answer: Supraspinatus
Correct Answer: Latissimus dorsi
Explanation:The latissimus dorsi forms the posterior wall of the axilla along with the scapula. It is responsible for extension, adduction, transverse extension also known as horizontal abduction, flexion from an extended position, and (medial) internal rotation of the shoulder joint. It also has a synergistic role in extension and lateral flexion of the lumbar spine.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 52
Incorrect
-
A terrorist running away from the police was shot in the back. The bullet hit his left lung halfway between its apex and the diaphragmatic surface. Which part of the lung was most likely to be injured?
Your Answer:
Correct Answer: Inferior lobe
Explanation:The oblique fissure of the left lung is so sharp that the posterior surface of the left lung is mostly composed of the inferior lobe so that the point halfway between the apex and the diaphragmatic surface of the lung would result in injury to the inferior lobe.
The hilum is the point on the medial surface of the lung where the structures that form the root of the lung enter and leave the lung.
The lingual on the other hand is part of the superior lobe of the left lung and it is part of the anterior and superior sides of the lung.
The middle lobe is only found on the right lung.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 53
Incorrect
-
What is the likely course of a pulmonary embolism arising from the leg veins and ending in the apical segmental pulmonary artery that supplies the superior lobe of left lung?.
Your Answer:
Correct Answer: Inferior vena cava – right atrium – tricuspid valve – right ventricle – pulmonary trunk – left pulmonary artery – left superior lobar artery – left apical segmental artery
Explanation:A clot originating in the leg vein will go to the inferior vena cava, into the right atrium, through the tricuspid valve, into the right ventricle, through the pulmonary trunk, into the left pulmonary artery, into the left superior lobar artery and then finally reach the left apical segmental artery.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 54
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.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 55
Incorrect
-
A young boy fell from a tree, sustaining an injury to the elbow area and damaging the nerve behind the medial epicondyle of the humerus. What is the most likely result from that injury?
Your Answer:
Correct Answer: Flexion in the distal interphalangeal joint of digit 5
Explanation:The nerve injured in this situation is the ulnar nerve. It passes posterior to the medial epicondyle of the humerus before going between the two heads of the flexor carpi ulnaris muscle. This nerve supplies the muscles and skin of forearm and hand. At the level of medial epicondyle, the injury will led to paralysis in flexor carpi ulnaris and the ulnar half of the flexor digitorum profundus as well as the palmar interossei and hypothenar muscles in the hand. The correct answer will be that the boy will suffer from inability to flex the distal interphalangeal joint of digit 5
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 56
Incorrect
-
When the pitch of a sound increases, what is the physiological response seen in the listener?
Your Answer:
Correct Answer: The location of maximal basilar membrane displacement moves toward the base of the cochlea
Explanation:An increase in the frequency of sound waves results in a change in the position of maximal displacement of the basilar membrane in the cochlea. Low pitch sound produces maximal displacement towards the cochlear apex and greatest activation of hair cells there. With an increasing pitch, the site of greatest displacement moves towards the cochlear base. However, increased amplitude of displacement, increase in the number of activated hair cells, increased frequency of discharge of units in the auditory nerve and increase in the range of frequencies to which such units respond, are all seen in increases in the intensity or a sound stimulus.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 57
Incorrect
-
Choose the most correct answer regarding the common peroneal nerve.
Your Answer:
Correct Answer: It gives rise to the nerve that supplies the anterior compartment leg muscles
Explanation:The common peroneal nerve divides beneath the peroneus longus muscle and gives off articular and lateral sural cutaneous nerves which supply muscular branches to the muscles of the anterior compartment of the leg which are the tibialis anterior, extensor digitorum, peroneus tertius and extensor hallucis longus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 58
Incorrect
-
A patient gives a history of dull discomfort in her abdomen associated with pain that she points to be on her right shoulder and right scapula. The following organs are most likely to be source of her pain:
Your Answer:
Correct Answer: Liver, duodenum and gallbladder
Explanation:Referred pain is felt at a point away from the source of the pain or the unpleasant sensation. It arises when a nerve is damaged or compressed at a point but the pain is felt at another site that is the territory of that nerve. Common abdominal causes of referred pain to the shoulder and the shoulder blade are the liver, duodenum and gall bladder.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 59
Incorrect
-
You observe a procedure to harvest the left internal thoracic (mammary) artery to be used as a graft for coronary artery bypass surgery. The left internal thoracic artery is mobilised from the inside of the chest wall and divided near the caudal end of the sternum. After dividing the internal thoracic artery at its distal end, the specialist registrar asks you to name the artery that will now have increased blood supply so that adequate blood flow is maintained to the rectus abdominis on the left side. What would your answer be?
Your Answer:
Correct Answer: Inferior epigastric artery
Explanation:The rectus abdominis muscle is supplied by the superior epigastric artery which is a branch of the internal thoracic artery. If the internal thoracic artery is thus ligated, blood would no longer flow to it. However, the superior epigastric artery communicates with the inferior epigastric artery (a branch of the external iliac artery). This means that blood could flow from the external iliac, to the inferior epigastric, to the superior epigastric to the rectus abdominis.
The superficial circumflex iliac artery and the superficial epigastric are two superficial branches of the femoral artery and do not supply the deep branches of the abdomen.
The deep circumflex iliac artery travels along the iliac crest on the inner surface of the abdominal wall; being too lateral it doesn’t supply blood to the rectus abdominis.
The distal portions of the umbilical arteries are obliterated in adults to form the medial umbilical folds.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 60
Incorrect
-
A neurotransmitter of the nigrostriatal pathway is:
Your Answer:
Correct Answer: Dopamine
Explanation:Dopamine acts as a neurotransmitter in the brain, activating dopamine receptors. It is also a neurohormone released from the hypothalamus. It plays an important role in the reward system. It is believed that dopamine provides a teaching signal to parts of the brain responsible for acquiring new motor sequences (behaviours), by activation of dopamine neurons when an unexpected reward is presented. Loss of dopamine neurones in the nigrostriatal pathway causes Parkinson’s disease. In the frontal lobes, dopamine controls the flow of information from other areas of the brain, and thus, dopamine disorders in this region can cause a decline in neurocognitive functions, especially memory, attention and problem solving. Reduced dopamine concentrations in the prefrontal cortex are thought to contribute to attention-deficit disorder and some symptoms of schizophrenia. Dopamine is also the primary neuroendocrine regulator of the secretion of prolactin from the anterior pituitary gland. Dopamine is also commonly associated with the pleasure system of the brain. This plays a key role in understanding the mechanism of action of drugs (such as cocaine and the amphetamines), which seem to be directly or indirectly related to the increase of dopamine.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 61
Incorrect
-
Mechanical distortion, and not K+ channels are responsible for distortion of which of the following structures?
Your Answer:
Correct Answer: Pacinian corpuscle
Explanation:Pacinian corpuscles are a type of mechanoreceptor, sensitive to deep pressure, touch and high-frequency vibration. The Pacinian corpuscles are ovoid and about 1 mm long. In the centre of the corpuscle is the inner bulb, which is a fluid-filled cavity with a single afferent unmyelinated nerve ending. Any deformation in the corpuscle causes the generation of action potentials by opening of pressure-sensitive sodium ion channels in the axon membrane. This allows influx of sodium ions, creating a receptor potential (independent of potassium channels).
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This question is part of the following fields:
- Neurology
- Physiology
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Question 62
Incorrect
-
Thalamic syndrome will most likely result in:
Your Answer:
Correct Answer: Hyperaesthesia
Explanation:Signs and symptoms of thalamic syndrome include contralateral hemi anaesthesia, burning or aching sensation in one half of a body (hyperaesthesia), often accompanied by mood swings.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 63
Incorrect
-
Rapid eye movement (REM) sleep is likely to be affected by a lesion in the:
Your Answer:
Correct Answer: Pons
Explanation:Rapid eye movement (REM) sleep is also known as paradoxical sleep, as the summed activity of the brain’s neurons is quite similar to that during waking hours. Characterised by rapid movements of the eyes, most of the vividly recalled dreams occur during this stage of sleep. The total time of REM sleep for an adult is about 90–120 min per night.
Certain neurones in the brainstem, known as REM sleep-on cells, which are located in the pontine tegmentum, are particularly active during REM sleep and are probably responsible for its occurrence. The eye movements associated with REM are generated by the pontine nucleus with projections to the superior colliculus and are associated with PGO (pons, geniculate, occipital) waves.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 64
Incorrect
-
Which best describes the sartorius muscle?
Your Answer:
Correct Answer: Will flex the leg at the knee joint
Explanation:The sartorius muscle arises from tendinous fibres from the superior iliac spine. It passes obliquely across the thigh from lateral to medial and is inserted into the upper part of the medial side of the tibia. When the sartorius muscle contracts it will flex the leg at the knee joint.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 65
Incorrect
-
A 70-year old man who is suspected to have a perforated colonic diverticulum is explored in theatre through a midline incision. This incision will be through the:
Your Answer:
Correct Answer: Linea alba
Explanation:The linea alba is the point where this incision was made. It is a tendinous raphe in the midline of the abdomen extending between the xiphoid process and the symphysis pubis. It is placed between the medial borders of the recti and is formed by the blending of the aponeuroses of the external and internal obliques and transversi.
The linea aspera is a vertical ridge on the posterior surface of the femur.
The arcuate line is the inferior border of the posterior rectus sheath behind the rectus abdominis muscle.
The semilunar line is the lateral margin of the rectus abdominis.
The iliopectineal line is a line on the pelvic bones formed by the arcuate line of the ilium and the pectineal line of the pubis.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 66
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.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 67
Incorrect
-
A man came to the hospital complaining of a sensation of pins and needles in the dorsum of the thumb and digits 1 and 2. On further examination they found that he had weakness in wrist dorsiflexion and finger extension. Which nerve do you think is injured in this case?
Your Answer:
Correct Answer: Radial
Explanation:The radial nerve can be injured in multiple sites along its course in the upper limb, and each site has its own presentation. The major complaint is wrist drop which if high above the elbow, can cause numbness of the forearm and hand. It can last for several days or weeks. The most common site of compression for the radial nerve is at the proximal forearm in the area of the supinator muscles.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 68
Incorrect
-
The transverse colon has two curvatures known as the colic flexures on each side of its lateral ends, the right and left. The left colic flexure found on the side of the descending colon is attached to an organ superiorly by a mesenteric ligament. Which organ is this?
Your Answer:
Correct Answer: Spleen
Explanation:The left colic flexure is the bend of the transverse colon as it continues to form the descending colon on the left upper quadrant. The spleen is located on the superior aspect of the left colic flexure. It is commonly referred to as the splenic flexure because of its relation o the spleen superiorly.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 69
Incorrect
-
Which of these structures is most likely to be damaged if a patient loses consciousness days or weeks after an otherwise insignificant head trauma, especially in elderly patients?
Your Answer:
Correct Answer: Dural bridging vein
Explanation:A subdural haematoma is a type of hematoma, usually associated with traumatic brain injury, in which blood collects between the dura mater and the pia-arachnoid mater. Symptoms of subdural haemorrhage have a slower onset than those of epidural haemorrhages because the lower pressure veins bleed more slowly than arteries. These injuries are more common in elderly patients, especially those taking antiplatelet or anticoagulant drugs. Oedema and increased intracranial pressure are unusual.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 70
Incorrect
-
A 25-year-old football player suffers severe head trauma during a game. Physical examination reveals a decerebrate posture and bilateral papilledema. A CT scan reveals marked diffuse cerebral oedema. This condition will be most severe in which component of the brain?
Your Answer:
Correct Answer: White matter
Explanation:The greatest amount of salt and water increase with cerebral oedema occurs within the white matter. Any swelling from oedema, haemorrhage or haematoma increases the intracranial pressure (ICP). As the ICP increases, the cerebral perfusion decreases and brain tissue can become ischaemic, even leading to brain death.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 71
Incorrect
-
During an anatomy revision session, medical students are told that the posterior wall of the rectus sheath ends in a thin curved margin whose concavity is directed downwards. What is the name of this inferior border of the rectus sheath?
Your Answer:
Correct Answer: Arcuate line
Explanation:The rectus sheath is a tendinous sheath that encloses the rectus abdominis muscle. It covers the entire anterior surface however on the posterior surface of the muscle the sheath is incomplete ending inferiorly at the arcuate line. Below the arcuate line, the rectus abdominis is covered by the transversalis fascia. The linea alba is a band of aponeurosis on the midline of the anterior abdominal wall, which extends from the xiphoid process to the pubic symphysis. It is formed by the combined abdominal muscle aponeuroses. This is a useful site for midline incision during abdominal surgery because it does not carry many blood vessels. All of the other answer choices are related to the inguinal canal.
The falx inguinalis (sometimes called the inguinal falx or conjoint tendon), is the inferomedial attachment of the transversus abdominis with some fibres of the internal abdominal oblique – it contributes to the posterior wall of the inguinal canal.
The inguinal ligament is the ligament that connects the anterior superior iliac spine with the pubic tubercle – it makes the floor of the inguinal canal.
The internal (deep) inguinal ring is the entrance to the inguinal canal, where the transversalis fascia pouches out and creates an opening through which structures can leave the abdominal cavity.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 72
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.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 73
Incorrect
-
A 70-year-old man who was previously healthy develops a rapidly progressing neurological deficit. A MRI reveals a large, poorly defined mass with central necrosis in his left temporal lobe. What is the most likely diagnosis?
Your Answer:
Correct Answer: Glioblastoma multiforme
Explanation:Glioblastoma multiforme, or grade 4 astrocytoma, is the most common and aggressive primary brain tumour. They are formed by small areas of necrotising tissue surrounded by highly anaplastic cells. Most of them arise from the deep white matter of the brain and quickly infiltrate it, becoming very large before they are symptomatic. The most common symptom is progressive memory, personality or neurological deficit due to temporal and frontal lobe involvement. It is most common in men, and risk factors include: neurofibromatosis, tuberous sclerosis, Von Hippel-Lindau disease, Li-Fraumeni syndrome, and Turcot syndrome.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 74
Incorrect
-
A man had noticed weakness in his left arm causing flexion of the elbow and supination of the forearm. Which nerve in this case was injured?
Your Answer:
Correct Answer: Musculocutaneous
Explanation:The musculocutaneous nerve supplies the biceps brachii and the brachialis muscles. The first one flexes the elbow and the shoulder. It is also involved in supination. The brachialis muscle flexes the forearm. The injury to the musculocutaneous nerve results in paralysis of these muscles.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 75
Incorrect
-
Which of the following statements is true regarding the umbilical cord?
Your Answer:
Correct Answer: Is filled with jelly of Wharton
Explanation:The umbilical cord that connects the fetus to the placenta is about 50cm long. This tissue consists of the body stalk and vitelline duct. The former containing the allantoic diverticulum and the umbilical vessels. The latter contains the connection linking the digestive tube and the yolk sac. This cord is wrapped by stratum of ectoderm and gelatinous tissue or jelly of Wharton. The right umbilical vein plus the vitelline vessels and ducts disappear and this at birth the cord has three vessels which are the umbilical vein and two umbilical arteries.
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This question is part of the following fields:
- Anatomy
- Embryology
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Question 76
Incorrect
-
The primary motor cortex is located in the:
Your Answer:
Correct Answer: Precentral gyrus
Explanation:The primary motor cortex is located in the dorsal part of the precentral gyrus and the anterior bank of the central sulcus. The precentral gyrus lies anterior to the postcentral gyrus and is separated from it by a central sulcus. Its anterior border is the precentral sulcus, while inferiorly it borders to the lateral fissure (Sylvian fissure).
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This question is part of the following fields:
- Neurology
- Physiology
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Question 77
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.
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This question is part of the following fields:
- Anatomy
- Neurology
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Question 78
Incorrect
-
A 60-year-old woman complains of left sided headaches which have been recurring for several years. She recently suffered from a focal seizure for the first time a few days ago. A CT scan shows a mass in the left hemisphere of the brain. The most likely diagnosis is:
Your Answer:
Correct Answer: Meningioma
Explanation:Meningiomas are a common benign intracranial tumour, and their incidence is higher in women between the ages of 40-60 years old. Many of these tumours are asymptomatic and are diagnosed incidentally, although some of them may have malignant presentations (less than 2% of cases). These benign tumours can develop wherever there is dura, over the convexities near the venous sinuses, along the base of the skull, in the posterior fossa and, within the ventricles.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 79
Incorrect
-
Which muscle would be affected most following injury to the transverse cervical artery?
Your Answer:
Correct Answer: Trapezius
Explanation:The latissimus dorsi receives blood from the thoracodorsal artery, the supraspinatus receives its blood from the suprascapular artery, the levator scapulae and the rhomboids are supplied by the dorsal scapular artery and the transverse cervical artery supplies blood to the trapezius.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 80
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.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 81
Incorrect
-
What is expected from complete transection of the inferior gluteal nerve when it emerges from the greater sciatic foramen?
Your Answer:
Correct Answer: Extension of the thigh would be the action most affected
Explanation:As the inferior gluteal nerve emerges from the greater sciatic foramen below the piriformis muscle, it divides into branches and enters the gluteus maximus muscle which extends the femur and bends the thigh in line with the body.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 82
Incorrect
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Which of the following structures is affected or damaged when the 'anterior drawer test' is positive?
Your Answer:
Correct Answer: Anterior cruciate ligament
Explanation:The anterior drawer test is an important orthopaedic test that is used to test weakness of the anterior cruciate ligament. The test is done by having the patient sit in a supine position with his/her knees flexed at 90 degrees. An examiner stabilises the patients feet and softly pulls or pushes on the proximal tibia. The test is positive if there is translational movement of the tibia in relation to the femur, indicating a weakened anterior cruciate ligament. The anterior cruciate ligament prevents the tibia from sliding out in front of the femur.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 83
Incorrect
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With respect to far accommodation, which of the following is a TRUE statement?
Your Answer:
Correct Answer: The ciliary muscles are relaxed
Explanation:Myopia or near-sightedness is a disease due to elongated eyeballs or too strong a lens. For far accommodation (focus of a distant object onto the retina), the lens needs to decrease its refractive power, or in other words, increase its focal length. This is done by relaxation of ciliary muscles which tightens the zonular fibres and flattening of the lens. Relaxation of the zonular fibres, rounding of the lens, shortening of the focal length and constriction of the pupil occurs during near accommodation.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 84
Incorrect
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A teacher had varicosities in the region of the small saphenous vein. Which of the following is true about that vein?
Your Answer:
Correct Answer: Has nine to twelve valves
Explanation:It is known that the small saphenous vein has nine to twelve valves along its course. This vein begins as a direct continuation of the lateral marginal vein posterior to the lateral malleolus. It is superficially situated but closer to its termination, perforates the deep fascia in the lower part of the popliteal fossa to end in the popliteal vein.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 85
Incorrect
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A recognised side-effect of prefrontal leukotomy is:
Your Answer:
Correct Answer: Confusion
Explanation:Used previously as a treatment for psychiatric disorders, prefrontal leucotomy severs the connection between the prefrontal cortical association area and the thalamus. This leads to functional isolation of the prefrontal and orbitofrontal association cortex. Thus, along with the desired reduction in anger and frustration, undesirable side effects included changes in mood and affect, as well as confusion.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 86
Incorrect
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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.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 87
Incorrect
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What is the arterial sequence for an analgesic to reach the latissimus dorsi muscle assuming that your starting point is at the subclavian vein?
Your Answer:
Correct Answer: Subclavian – axillary – subscapular – thoracodorsal
Explanation:Assuming our starting point is the subclavian artery, the analgesic continues in the same vessel into the axillary artery, as it passes into the axilla. The axillary artery at the lower border of the subscapularis gives rise to the subcapsular artery which is considered the largest branch of the axillary artery. This circumflex scapular branch distributes a serratus branch before entering the substance of the muscle as the thoracodorsal artery.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 88
Incorrect
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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.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 89
Incorrect
-
A lesion involving the suprachiasmatic nucleus of hypothalamus is likely to affect:
Your Answer:
Correct Answer: Regulation of circadian rhythm
Explanation:The suprachiasmatic nucleus (SCN) in the hypothalamus is responsible for controlling endogenous circadian rhythms and destruction of the SCN leads to a loss of circadian rhythm.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 90
Incorrect
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upon stroking the plantar surface of a patient's foot, extension of toes was noted. This is likely to be accompanied with:
Your Answer:
Correct Answer: Spasticity
Explanation:An upper motor neuron lesion affects the neural pathway above the anterior horn cell or motor nuclei of the cranial nerves, whereas a lower motor neurone lesion affects nerve fibres travelling from the anterior horn of the spinal cord to the relevant muscles. An upper motor neurone lesions results in the following:
– Spasticity in the extensor muscles (lower limbs) or flexor muscles (upper limbs).
– ‘clasp-knife’ response where initial resistance to movement is followed by relaxation
– Weakness in the flexors (lower limbs) or extensors (upper limbs) with no muscle wasting
– Brisk tendon jerk reflexes
– Positive Babinski sign (on stimulation of the sole of the foot, the big toe is raised rather than curled downwards)
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This question is part of the following fields:
- Neurology
- Physiology
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Question 91
Incorrect
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Infection to all of the following will lead to enlargement of the superficial inguinal lymph nodes, except for:
Your Answer:
Correct Answer: Ampulla of the rectum
Explanation:The superficial inguinal lymph nodes form a chain immediately below the inguinal ligament. They receive lymphatic supply from the skin of the penis, scrotum, perineum, buttock and abdominal wall below the level of the umbilicus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 92
Incorrect
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A 60 year-old patient being treated for hypertension presents to the ED with swelling of the left upper limb due to poor venous return. On examination, it is found that an aneurysm of the ascending aorta is impinging on a large vein lying immediately anterosuperior to it. Which vein is it likely to be?
Your Answer:
Correct Answer: Left brachiocephalic
Explanation:Among the veins listed, only the left brachiocephalic vein is anterosuperior to the ascending aorta. The right brachiocephalic vein being on the right side would not be affected by the aortic aneurysm.
The azygos vein lies deep in the chest on the right side.
The internal thoracic vein lies interior to the anterior wall of the chest.
The left superior intercostal vein is close to the aortic arch, crossing it laterally. This vein drains the 2nd to 4th interspaces on the left side.
The Right internal jugular vein joins the right brachiocephalic vein which would not be affected by the aneurysm.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 93
Incorrect
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Which of the following veins is prostate cancer most likely to metastasize through?
Your Answer:
Correct Answer: Internal vertebral venous plexus
Explanation:The internal vertebral veins are the most likely route of metastasis as they are valveless. They serve an important clinical role as they are the route of free travel for cancerous cells to other body structures. The other veins on the list have valves and would be the least likely routes for metastasis.
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This question is part of the following fields:
- Anatomy
- Neurology
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Question 94
Incorrect
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What is the nerve supply to the muscles of the lateral compartment of the leg ?
Your Answer:
Correct Answer: Superficial peroneal nerve
Explanation:The peroneus longus and peroneus brevis in the lateral compartment of the leg take nerve supply from the superficial peroneal nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 95
Incorrect
-
Which of the following is true about myasthenia gravis?
Your Answer:
Correct Answer: Response of skeletal muscle to nerve stimulation is weakened
Explanation:An autoimmune disorder, myasthenia gravis leads to progressive muscle weakness. It occurs due to formation of antibodies against the nicotinic acetylcholine (ACh) receptor of the motor endplate, which leads to impaired neuromuscular transmission. Thus, nerve stimulation will lead to a weakened muscle response, but direct electrical stimulation will bring about a normal response. Diagnostic test includes improvement of muscle weakness by small doses of acetylcholinesterase inhibitors (physostigmine or edrophonium). However, a large dose of physostigmine worsens the weakness due to desensitisation of the endplate to persistent Ach. One of the investigative tools includes radiolabelled snake venom α-bungarotoxin. It is an in vitro study performed on muscle biopsy specimens and used to quantify the number of ACh receptors at the motor endplate.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 96
Incorrect
-
Injury to the supraspinatus muscle will affect:
Your Answer:
Correct Answer: Initiation of abduction of the humerus
Explanation:This muscle arises from the medial two-thirds of the supraspinatus fossa and from the supraspinatus fascia. It is inserted into the highest impression on the greater tubercle of the humerus after passing over the upper part of the shoulder joint. It works with the deltoid to raise the arm from the side of the trunk and initiate abduction. It also assists in fixation of the head of the humerus in the glenoid cavity.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 97
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:
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.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 98
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
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 99
Incorrect
-
Which best describes the suprascapular nerve?
Your Answer:
Correct Answer: It contains nerve fibres from C5 and C6 spinal cord segments
Explanation:The suprascapular nerve arises from the cervical spinal nerves 5 and 6 after coming together to form common trunk. This nerve supplies the supraspinatus and infraspinatus muscles giving off branches to the shoulder joint.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 100
Incorrect
-
A patient who complained of pain on the lower left side of the back had an x-ray done which confirmed a hernia passing posterolaterally, just superior to the iliac crest. Where is this hernia passing through?
Your Answer:
Correct Answer: Lumbar triangle
Explanation:The lumber triangle is bound medially by the border of the latissimus dorsi, laterally by the external abdominal oblique and by the iliac crest inferiorly. This is exactly where the hernia that is described is located.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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SESSION STATS - PERFORMANCE PER SPECIALTY
