-
Question 1
Correct
-
Internal haemorrhoids are painless and only sensitive to stretch. They are formed from folds of the mucous membrane and the submucosa of the anal canal which contain varicose branches of the:
Your Answer: Superior rectal vein
Explanation:Internal haemorrhoids are formed by varicosities of the branches of the superior rectal vein.
External haemorrhoids are formed by varicosities of the branches of the inferior rectal vein.
-
This question is part of the following fields:
- Anatomy
- Colorectal
-
-
Question 2
Correct
-
Rapid eye movement (REM) sleep is likely to be affected by a lesion in the:
Your 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.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 3
Correct
-
A 30-year-old man is brought to the emergency department suffering from extreme dehydration, and subsequent hypotension and tachycardia. Which part of the kidney will compensate for this loss?
Your Answer: Collecting ducts
Explanation:The collecting duct system of the kidney consists of a series of tubules and ducts that physically connect nephrons to a minor calyx or directly to the renal pelvis. The collecting duct system is the last component of the kidney to influence the body’s electrolyte and fluid balance. In humans, the system accounts for 4–5% of the kidney’s reabsorption of sodium and 5% of the kidney’s reabsorption of water. At times of extreme dehydration, over 24% of the filtered water may be reabsorbed in the collecting duct system.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 4
Incorrect
-
A 20 year old is brought to the A&E after he fell from a moving cart. The boy has sustained blunt abdominal injury, and the there is a possibility of internal bleeding as the boy is in shock. An urgent exploratory laparotomy is done in the A&E theatre. On opening the peritoneal cavity, the operating surgeon notices a torn gastrosplenic ligament with a large clot around the spleen. Which artery is most likely to have been injured in this case?
Your Answer: Left gastroepiploic
Correct Answer: Short gastric
Explanation:The short gastric arteries branch from the splenic artery near the splenic hilum to travel back in the gastrosplenic ligament to supply the fundus of the stomach. Therefore, these may be injured in this case.
The splenic artery courses deep to the stomach to reach the hilum of the spleen. It doesn’t travel in the gastrosplenic ligament although it does give off branches that do.
The middle colic artery is a branch of the superior mesenteric artery that supplies the transverse colon.
Gastroepiploic artery is the largest branch of the splenic artery that courses between the layers of the greater omentum to anastomose with the right gastroepiploic.
Left gastric artery, a branch of the coeliac trunk. It supplies the left half of the lesser curvature.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 5
Correct
-
A patient with a long standing lower motor neuron lesion will have:
Your Answer: Muscle wasting
Explanation:Lower motor neurons (LMNs) connect the brainstem and spinal cord to muscle fibres. Damage to lower motor neurons is indicated by abnormal electromyographic potentials, fasciculations, paralysis, weakening and wasting of skeletal muscles.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 6
Incorrect
-
A 62-year-old male smoker, presented with shortness of breath, chronic cough and haemoptysis over the last three months. He has developed a fat pad in the base of his neck, rounded face, acne and osteoporosis. Which of the following is the most likely pulmonary disease that is causing these symptoms and findings?
Your Answer: Pulmonary adenocarcinoma
Correct Answer: Small-cell anaplastic carcinoma
Explanation:Small cell lung cancer is a highly aggressive form of lung cancer. It is thought to originate from neuroendocrine cells in the bronchus called Feyrter cells and is often associated to ectopic production of hormones like ADH and ACTH that result in paraneoplastic syndromes and Cushing’s syndrome.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 7
Incorrect
-
A 26-year-old female sought consultation due to excessive vaginal discharge. Vaginal smear showed numerous bacilli under the microscope. The organism was non-pathogenic. What is the most likely organism:
Your Answer: Escherichia coli
Correct Answer: Lactobacillus species
Explanation:Lactobacillus is a Gram-positive facultative bacteria. It is commonly present in the vagina and the gastrointestinal tract. Colonization of Lactobacillus is usually benign and it makes up a small portion of the gastrointestinal flora.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 8
Correct
-
The otic ganglion receives its preganglionic sympathetic fibres from which of the following nerves?
Your Answer: Glossopharyngeal nerve
Explanation:The otic ganglion is a small (2–3 mm), oval shaped, flattened parasympathetic ganglion of a reddish-grey colour, located immediately below the foramen ovale in the infratemporal fossa and on the medial surface of the mandibular nerve. The preganglionic parasympathetic fibres originate in the inferior salivatory nucleus of the glossopharyngeal nerve. They leave the glossopharyngeal nerve by its tympanic branch and then pass via the tympanic plexus and the lesser petrosal nerve to the otic ganglion. Here, the fibres synapse, and the postganglionic fibres pass by communicating branches to the auriculotemporal nerve, which conveys them to the parotid gland. They produce vasodilator and secretomotor effects.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 9
Correct
-
The pleural cavity is the space between the two pulmonary pleurae which cover the lungs. What is the normal amount of pleural fluid?
Your Answer: 10 ml
Explanation:Pleural fluid is a serous fluid produced by the serous membrane covering normal pleurae. Most fluid is produced by the parietal circulation (intercostal arteries) via bulk flow and reabsorbed by the lymphatic system. The total volume of fluid present in the intrapleural space is estimated to be only 2–10 ml. A small amount of protein is present in intrapleural fluid. Normally, the rate of reabsorption increases as a physiological response to accumulating fluid.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 10
Correct
-
Which statement is true regarding the diaphragmatic openings:
Your 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.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 11
Correct
-
Which of the cranial nerves is responsible for touch sensation on the skin over the maxilla region and the mandible?
Your Answer: Trigeminal
Explanation:The sensation of the face is provided by the trigeminal nerve which is cranial nerve V. It is also responsible for other motor functions such as biting and chewing. The trigeminal nerve has three branches; the ophthalmic nerve (V1), the maxillary nerve((V2) and the mandibular nerve (V3). These three branches exit the skull through separate foramina, namely; the superior orbital fissure, the foramen rotundum and the foramen ovale respectively. The mnemonic for this is ‘Standing room only’. The sensory fibres of the maxillary nerve are distributed to the lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges. The sensory fibres of the mandibular nerve are distributed to the lower lip, the lower teeth and gums, the floor of the mouth, the anterior two-thirds of the tongue, the chin and jaw (except the angle of the jaw, which is supplied by C2–C3), parts of the external ear, and parts of the meninges. The mandibular nerve carries touch/ position and pain/temperature sensation from the mouth. The sensory fibres of the ophthalmic nerve are distributed to the scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose), the nasal mucosa, the frontal sinuses and parts of the meninges (the dura and blood vessels). The sensory fibres of the maxillary nerve are distributed to the lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 12
Correct
-
A 12-year old girl was brought to the hospital with recurrent headaches for 6 months. Her physical examination revealed no abnormality. A CT scan of the head revealed a suprasellar mass with calcifications, eroding the surrounding sella turcica. The lesion is likely to represent:
Your Answer: Craniopharyngioma
Explanation:Craniopharyngiomas (also known as Rathke pouch tumours, adamantinomas or hypophyseal duct tumours) affect children mainly between the age of 5 and 10 years. It constitutes 9% of brain tumours affecting the paediatric population. These are slow-growing tumours which can also be cystic, and arise from the pituitary stalk, specifically the nests of epithelium derived from Rathke’s pouch. Histologically, this tumour shows nests of squamous epithelium which is lined on the outside by radially arranged cells. Calcium deposition is often seen with a papillary type of architecture.
ACTH-secreting pituitary adenomas are rare and mostly microadenomas. Paediatric astrocytoma’s usually occur in the posterior fossa. Although null cell adenomas can cause mass effect and give rise to the described symptoms, they are not suprasellar. Prolactinomas can also show symptoms of headache and disturbances in the visual field, however they are known to be small and slow-growing.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 13
Correct
-
In a young, sexually active male, what is the most common cause of non-gonococcal urethritis?
Your Answer: Chlamydia
Explanation:Non-gonococcal urethritis is most commonly caused by Chlamydia trachomatis (50% cases). Less common organisms include Mycoplasma genitalium, Urea urealyticum and Trichomonas vaginalis. Chlamydia is also the commonest cause of non-gonococcal cervicitis in women and proctitis in both sexes.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 14
Correct
-
Which of the following conditions is likely to result in splenomegaly, hypochromic anaemia and hemochromatosis in a young male?
Your Answer: β-Thalassaemia
Explanation:Beta-thalassaemia is due to decreased production of β-polypeptide chains, with an autosomal inheritance pattern. Carrier patients (heterozygotes) are asymptomatic and have mild to moderate microcytic anaemia. This is known as thalassaemia minor. Homozygotes (β-thalassaemia major, or Cooley’s anaemia) develop severe anaemia and marrow hyperactivity. The disease presents at 1-2 years of age with severe anaemia and transfusional and absorptive iron overload. Patients also present with jaundice, leg ulcers, massive splenomegaly and cholelithiasis. The disease can also lead to splenic sequestration leading to faster destruction of transfused red blood cells. Increased marrow activity causes thickening of cranial bones. Involvement of long bones is also seen, which can cause pathological fractures and growth impairment. There is iron deposition in various organs, which can lead to heart failure or hepatic failure (leading to cirrhosis). Thalassaemias are suspected in presence of family history, or signs suggesting microcytic haemolytic anaemia. Further test and quantitative haemoglobin studies are useful. In beta-thalassaemia, there is an increase in serum bilirubin, iron and ferritin levels. There is severe anaemia, often with haemoglobin < 6 g/dl. There is an elevated red blood cell count, which are microcytic. Peripheral blood smear is diagnostic with nucleated erythroblasts, target cells, small pale red blood cells, and punctate basophilia.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 15
Correct
-
When at rest, which of the following will be higher in a marathon runner compared to an untrained individual?
Your Answer: Cardiac stroke volume
Explanation:Cardiac muscle hypertrophy is seen in trained athletes as compared to the normal population. This hypertrophy results in higher stroke volume at rest and increased cardiac reserve (maximum cardiac output during exercise). However, the cardiac output at rest is almost the same in both trained and untrained people. This is because in trained athletes, the heart rate is slower, even up to 40-50 beats/min. There is minimal affect of athletic training on oxygen consumption and respiratory rate.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 16
Incorrect
-
A 48-year-old woman has a mass in her right breast and has right axillary node involvement. She underwent radical mastectomy of her right breast. The histopathology report described the tumour to be 4 cm in its maximum diameter with 3 axillary lymph nodes with evidence of tumour. The most likely stage of cancer in this patient is:
Your Answer: IIIA
Correct Answer: IIB
Explanation:Stage IIB describes invasive breast cancer in which: the tumour is larger than 2 centimetres but no larger than 5 centimetres; small groups of breast cancer cells — larger than 0.2 millimetre but not larger than 2 millimetres — are found in the lymph nodes OR the tumour is larger than 2 centimetres but no larger than 5 centimetres; cancer has spread to 1 to 3 axillary lymph nodes or to lymph nodes near the breastbone (found during a sentinel node biopsy) OR the tumour is larger than 5 centimetres but has not spread to the axillary lymph nodes.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 17
Correct
-
Which of the following toxins most likely results in continuous cAMP production, which pumps H2O, sodium, potassium, chloride and bicarbonate into the lumen of the small intestine and results in rapid dehydration?
Your Answer: Cholera toxin
Explanation:The cholera toxin (CTX or CT) is an oligomeric complex made up of six protein subunits: a single copy of the A subunit (part A), and five copies of the B subunit (part B), connected by a disulphide bond. The five B subunits form a five-membered ring that binds to GM1 gangliosides on the surface of the intestinal epithelium cells. The A1 portion of the A subunit is an enzyme that ADP-ribosylates G proteins, while the A2 chain fits into the central pore of the B subunit ring. Upon binding, the complex is taken into the cell via receptor-mediated endocytosis. Once inside the cell, the disulphide bond is reduced, and the A1 subunit is freed to bind with a human partner protein called ADP-ribosylation factor 6 (Arf6). Binding exposes its active site, allowing it to permanently ribosylate the Gs alpha subunit of the heterotrimeric G protein. This results in constitutive cAMP production, which in turn leads to secretion of H2O, Na+, K+, Cl−, and HCO3− into the lumen of the small intestine and rapid dehydration. The gene encoding the cholera toxin was introduced into V. cholerae by horizontal gene transfer.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 18
Incorrect
-
13 year old girl developed sun burnt cheeks after spending the day playing on the beach. What is the underlying mechanism to her injury?
Your Answer: Damage to DNA
Correct Answer: Free radical injury
Explanation:Free radicals are a by-product of chemical reactions with an unpaired electron in their outer most shell. They are capable of causing wide spread damage to cells. They can cause autolytic reactions thereby converting the reactants into free radicals. By absorbing sun light, the energy is used to hydrolyse water into hydroxyl (OH) and hydrogen (H) free radicals which can cause injury by lipid peroxidation of membranes, oxidative modification of proteins and damage to the DNA structure.
-
This question is part of the following fields:
- Cell Injury & Wound Healing; Dermatology
- Pathology
-
-
Question 19
Correct
-
The gastrosplenic ligament also known as the gastrolienal ligament is the structure that connects the greater curvature of the stomach to the hilum of the spleen. Which of the following arteries would most likely be injured if a surgeon accidentally tore this ligament?
Your Answer: Short gastric
Explanation:The short gastric arteries arise from the end of the splenic arteries and form five to seven branches. The short gastric arteries inside the gastrosplenic ligament from the left to the right, supply the greater curvature of the stomach. The hepatic artery proper runs inside the hepatoduodenal ligament. The right gastric artery and the left gastric artery are contained in the hepatogastric ligament. The caudal pancreatic artery branches off from the splenic artery and supplies the tail of the pancreas. The middle colic artery supplies the transverse colon. The splenic artery does not travel in the gastrosplenic ligament and so it would not be damaged by a tear to this ligament.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 20
Correct
-
A 40-year-old woman is suspected to have an ovarian cancer. Which tumour marker should be requested to confirm the diagnosis?
Your Answer: CA-125
Explanation:CA-125 is a protein that is used as a tumour marker. This substance is found in high concentration in patients with ovarian cancer. It is the only tumour marker recommended for clinical use in the diagnosis and management of ovarian cancer.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 21
Correct
-
An experiment was conducted in which the skeletal muscle protein (not smooth muscle) involved in contraction was selectively inhibited. Which protein was inhibited?
Your Answer: Troponin
Explanation:The mechanism of contraction of smooth muscles is different from that of skeletal muscles in which the contractile protein is troponin whilst in smooth muscle contraction is a protein called calmodulin. Calmodulin reacts with calcium ions and stimulates the formation of myosin crossbridges.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 22
Correct
-
In which of the following situations will fat necrosis occur?
Your Answer: Trauma to the breast
Explanation:Fat necrosis is necrosis of adipose tissue with subsequent deposition of calcium, giving it a white chalky appearance. It is seen characteristically in trauma to the breast and the pancreas with subsequent involvement of the peripancreatic fat. In the breast it may present as a palpable mass with is usually painless or as an incidental finding on mammogram. Fatty acids are released from the traumatic tissue which combine with calcium in a process known as saponification, this is an example of dystrophic calcification in which calcium binds to dead tissue. The central focus is surrounded by macrophages and neutrophils initially, followed by proliferation of fibroblasts, neovascularization and lymphocytic migration to the site of the insult.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 23
Incorrect
-
Which of the following arteries is the posterior branch of the external carotid artery?
Your Answer: Occipital
Correct Answer: Superficial temporal
Explanation:The external carotid artery is a branch of the common carotid artery that supplies parts of the neck, head and face. It branches off from the common carotid artery at the level of the thyroid cartilage. The external carotid, at the level of the mandible divides into the maxillary artery and the superficial temporal. The superficial temporal artery is the posterior branch of these two arteries. It starts off, somewhat, as a continuation of the external carotid artery at the substance of the parotid gland. Anterior cerebral and middle cerebral arteries are branches of the internal carotid artery.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 24
Correct
-
Whilst snorkelling, a 30-year old gentleman has the respiratory rate of 10/min, tidal volume of 550 ml and an effective anatomical dead space of 250 ml. What is his alveolar ventilation?
Your Answer: 3000 ml/min
Explanation:Alveolar ventilation is the amount of air reaching the alveoli per minute. Alveolar ventilation = respiratory rate × (tidal volume – anatomical dead space volume). Thus, alveolar ventilation = 10 × (550 − 250) = 3000 ml/min.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 25
Correct
-
A chloride sweat test was performed on a 13-year-old boy. Results indicated a high likelihood of cystic fibrosis. This diagnosis is associated with a higher risk of developing which of the following?
Your Answer: Bronchiectasis
Explanation:Cystic fibrosis is a life-threatening disorder that causes the build up of thick mucus in the lungs, digestive tract, and other areas of the body. It is a hereditary autosomal-recessive disease caused by mutations of the CFTR gene. Cystic fibrosis eventually results in bronchiectasis which is defined as a permanent dilatation and obstruction of bronchi or bronchioles.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 26
Incorrect
-
A surgical registrar performing an adrenalectomy procedure on the left suprarenal gland of a 25 - year old male patient, accidentally jabbed and injured a vital structure that lies anterior to the left suprarenal organ. Which of the following was the structure most likely injured?
Your Answer: Colon
Correct Answer: Pancreas
Explanation:The adrenal (suprarenal) glands are organs of the endocrine system located on top of each of the kidneys. The left suprarenal gland, in question, is crescent in shape and slightly larger than the right suprarenal gland. It is posteriorly located to the lateral aspect of the head of the pancreas which is thus the most likely to be injured. The other organs like the duodenum, liver and the inferior vena cava are related to the right suprarenal gland. The spleen and the colon are not in close proximity with the left suprarenal gland and are not likely to be the organs injured.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 27
Correct
-
A 62-year-old man presented with a persistent cough and weight loss. Chest x-ray demonstrated widespread nodular opacities. After a bronchoalveolar lavage, atypical cells were detected. Which is the most probable diagnosis?
Your Answer: Bronchioalveolar carcinoma
Explanation:Bronchioloalveolar carcinoma (BAC) is a term used to define a particular subtype of adenocarcinoma which develops in cells near the alveoli, in the outer regions of the lungs. On a chest X-ray it can appear as a single peripheral spot or as scattered spots throughout the lungs. Symptoms include cough, haemoptysis, chest pain, dyspnoea and loss of weight.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 28
Correct
-
Which of the following morphological characteristic is a salient feature of a pure apoptotic cell?
Your Answer: Chromatin condensation
Explanation:Apoptosis is the programmed death of cells which occurs as a normal and controlled part of an organism’s growth or development. The changes which occur in this process include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, chromosomal DNA fragmentation, and global mRNA decay. The cell membrane however remains intact and the dead cells are phagocytosed prior to any content leakage and thus inflammatory response.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 29
Correct
-
Which of the following conditions is characterized by generalised oedema due to effusion of fluid into the extracellular space?
Your Answer: Anasarca
Explanation:Anasarca (or ‘generalised oedema’) is a condition characterised by widespread swelling of the skin due to effusion of fluid into the extracellular space. It is usually caused by liver failure (cirrhosis of the liver), renal failure/disease, right-sided heart failure, as well as severe malnutrition/protein deficiency.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 30
Correct
-
After finding elevated PSA levels, a 69-year-old man undergoes a needle biopsy and is diagnosed with prostatic cancer. What is the stage of this primary tumour?
Your Answer: T1c
Explanation:The AJCC uses a TNM system to stage prostatic cancer, with categories for the primary tumour, regional lymph nodes and distant metastases:
TX: cannot evaluate the primary tumour T0: no evidence of tumour
T1: tumour present, but not detectable clinically or with imaging T1a: tumour was incidentally found in less than 5% of prostate tissue resected (for other reasons)
T1b: tumour was incidentally found in more than 5% of prostate tissue resected
T1c: tumour was found in a needle biopsy performed due to an elevated serum prostate-specific antigen
T2: the tumour can be felt (palpated) on examination, but has not spread outside the prostate
T2a: the tumour is in half or less than half of one of the prostate gland’s two lobes
T2b: the tumour is in more than half of one lobe, but not both
T2c: the tumour is in both lobes
T3: the tumour has spread through the prostatic capsule (if it is only part-way through, it is still T2)
T3a: the tumour has spread through the capsule on one or both sides
T3b: the tumour has invaded one or both seminal vesicles
T4: the tumour has invaded other nearby structures.
In this case, the tumour has a T1c stage.
-
This question is part of the following fields:
- Pathology
- Urology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
