-
Question 1
Incorrect
-
What is the action of the muscle of the orbit that originates on the lesser wing of the sphenoid bone, just above the optic foramen?
Your Answer: Temporal rotation of the eyeball
Correct Answer: Elevation of the upper eyelid
Explanation:The levator palpebrae superioris is the muscle in the orbit that elevates the superior (upper) eyelid. The levator palpebrae superioris originates on the lesser wing of the sphenoid bone, just above the optic foramen and receives somatic motor input from the ipsilateral superior division of the oculomotor nerve.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 2
Correct
-
The tympanic membrane is a thin semi-transparent membrane that separates the tympanic cavity from the bottom of the external acoustic meatus. The interior of the tympanic membrane is innervated by which of the following cranial nerves?
Your Answer: Glossopharyngeal
Explanation:The glossopharyngeal nerve, known as the ninth cranial nerve (CN IX), is a mixed nerve that carries afferent sensory and efferent motor information. The glossopharyngeal nerve has five distinct general functions:
– The branchial motor (special visceral efferent), supplies the stylopharyngeus muscle.
– The visceral motor (general visceral efferent), provides parasympathetic innervation of the parotid gland via the otic ganglion.
– The visceral sensory (general visceral afferent), carries visceral sensory information from the carotid sinus and carotid body.
– The general sensory (general somatic afferent), provides general sensory information from the inner surface of the tympanic membrane, upper pharynx (GVA), and the posterior one-third of the tongue.
– The visceral afferent (special visceral afferent), provides taste sensation from the posterior one-third of the tongue, including the circumvallate papillae.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 3
Incorrect
-
Chest X-ray of a 45-year old gentleman with a week history of pleurisy showed a small pneumothorax with moderate-sized pleural effusion. Arterial blood gas analysis showed p(CO2) = 23 mmHg, p(O2) = 234.5 mmHg, standard bicarbonate = 16 mmol/l. What are we most likely dealing with?
Your Answer: Compensated respiratory acidosis
Correct Answer: Compensated respiratory alkalosis
Explanation:Normal pH with low p(CO2) and low standard bicarbonate could indicate either compensated respiratory alkalosis or a compensated metabolic acidosis. However, the history of hyperventilation for 5 days (pleurisy) favours compensated respiratory alkalosis. Compensated metabolic acidosis would have been likely in a diabetic patient with fever, vomiting and high glucose (diabetic ketoacidosis).
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 4
Correct
-
Where is the foramen ovale located?
Your Answer: Sphenoid
Explanation:The foramen ovale is an oval shaped opening in the middle cranial fossa located at the posterior base of the greater wing of the sphenoid bone, lateral to the lingula. It transmits the mandibular division of the trigeminal nerve (CN Vc), accessory meningeal artery, emissary veins between the cavernous sinuses and pterygoid plexus, otic ganglion, and occasionally the nervus spinosus and lesser petrosal nerve.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 5
Correct
-
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: 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.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 6
Incorrect
-
During an exploratory laparotomy a herniation of bowel is identified between the lateral edge of the rectus abdominis, the inguinal ligament and the inferior epigastric vessels. These boundaries define the hernia as being a:
Your Answer: Indirect inguinal hernia
Correct Answer: Direct inguinal hernia
Explanation:The boundaries given define the inguinal triangle which is the site for direct inguinal hernias. Indirect inguinal hernias occur lateral to the inferior epigastric vessels.
Femoral hernias protrude through the femoral ring, into the femoral canal.
Umbilical hernias protrude through a defect in the umbilical area.
Obturator hernias, occur through the obturator foramen. These are very rare.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 7
Correct
-
Which of the following will be a seen in a patient with a plasma thyroid-stimulating hormone (TSH) level of 14 mU/l (normal < 5 mU/l) and a low T3 resin uptake of 19% (normal 25–35%)?
Your Answer: Periorbital swelling and lethargy
Explanation:Low T3 resin uptake combined with raised TSH is indicative of hypothyroidism. Signs and symptoms include dull expression, facial puffiness, lethargy, periorbital swelling due to infiltration with mucopolysaccharides, bradycardia and cold intolerance. Anxiety, palpitations, tachycardia, raised body temperature, heat intolerance and weight loss are all seen in hyperthyroidism.
-
This question is part of the following fields:
- Endocrinology
- Physiology
-
-
Question 8
Incorrect
-
Coagulation in the body (in vivo) is a process in which several proteins known as coagulation factors are activated in a cascade effect to stop bleeding. Which of the following initiates this cascade effect?
Your Answer: Factor VII
Correct Answer: Tissue factor
Explanation:Tissue factor (TF), also known as ‘factor III’ or ‘thromboplastin’, is an anti-coagulation protein that initiates the extrinsic coagulation. TF acts as a transmembrane receptor for Factor VII/VIIa . It is expressed by endothelial cells but also certain tissues, such as the heart and brain.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 9
Correct
-
Which of the following will show decreased hearing when tested by air conduction but normal hearing when tested by bone conduction?
Your 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.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 10
Correct
-
Which of the following statements regarding the femoral artery is CORRECT?
Your Answer: It has the femoral nerve lying lateral to it
Explanation:The femoral artery begins immediately behind the inguinal ligament, midway between the anterior superior spine of the ilium and the symphysis pubis. The first 4 cm of the vessel is enclosed, together with the femoral vein, in a fibrous sheath (the femoral sheath). The femoral nerve lies lateral to this.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 11
Correct
-
A football player sustained an injury to his ankle. The wound went through the skin, subcutaneous tissue and flexor retinaculum. Which other structure passing under the retinaculum may be injured?
Your Answer: Tibial nerve
Explanation:The flexor retinaculum is immediately posterior to the medial malleolus. The structures that pass under the flexor retinaculum from anterior to posterior are: tendon of the tibialis posterior, flexor digitorum longus, posterior tibial artery (and vein), tibial nerve and tendon of flexor hallucis longus. The tibial nerve is the only one which lies behind the flexor retinaculum.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 12
Incorrect
-
The majority of gallstones are mainly composed of:
Your Answer: Bile salts
Correct Answer: Cholesterol
Explanation:Bile salts are formed out of cholesterol in the liver cells. Occasionally, precipitation of cholesterol occurs resulting into cholesterol stones developing in the gall bladder.
These cholesterol gallstones are the most common type and account for 80% of all gallstones. Another type, accounting for 20% gallstones is pigment stones which are composed of bilirubin and calcium salts. Occasionally, stones of mixed origin are also seen.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 13
Correct
-
A 54-year-old woman is re-admitted to the hospital with shortness of breath and sharp chest pain 2 weeks after surgical cholecystectomy. The most probable cause of these clinical findings is:
Your Answer: Pulmonary embolus
Explanation:Pulmonary embolism is caused by the sudden blockage of a major lung blood vessel, usually by a blood clot. Symptoms include sudden sharp chest pain, cough, dyspnoea, palpitations, tachycardia or loss of consciousness. Risk factors for developing pulmonary embolism include long periods of inactivity, recent surgery, trauma, pregnancy, oral contraceptives, oestrogen replacement, malignancies and venous stasis.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 14
Correct
-
What's the nodal stage of a testicular seminoma if several lymph nodes between 2cm and 5cm are found?
Your Answer: N2
Explanation:According to the American Joint Committee on Cancer (AJCC) 2002 guidelines, the nodal staging of testicular seminoma is the following:
N0: no regional lymph node metastases
N1: metastasis with lymph nodes 2 cm or less in their greatest dimension or multiple lymph nodes, none more than 2 cm
N2: metastasis with lymph nodes greater than 2 cm but not greater than 5 cm in their greatest dimension, or multiple lymph nodes, any one mass greater than 2 cm, but not more than 5 cm
N3: metastasis with lymph nodes greater than 5 cm in their greatest dimension.
The patient in this case has N2 testicular seminoma. This TNM staging is extremely important because treatment options are decided depending on this classification.
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 15
Incorrect
-
In a cardiac cycle, what event does the closing of atrioventricular (AV) valves coincide with?
Your Answer: Beginning of diastole
Correct Answer: First heart sound
Explanation:In the cardiac cycle, the closing of the atrioventricular (AV) valves coincides with the onset of ventricular systole. This event marks the beginning of the isovolumetric contraction phase, where the ventricles begin to contract, but the volume of blood in the ventricles remains the same because both the AV valves and the semilunar valves (aortic and pulmonary valves) are closed. The closing of the AV valves produces the first heart sound, known as “S1” or “lub.”
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 16
Correct
-
A lady presents to the out patient clinic with a painful boil on the skin of her mons pubis. Which nerve supplies the skin of the mons pubis?
Your Answer: Anterior labial
Explanation:Anterior labial branch is the terminal branch of the ilioinguinal nerve that innervates the skin of the mons pubis in women and the skin of the anterior scrotum in men.
The femoral branch of genitofemoral nerve innervates the upper medial thigh.
The iliohypogastric innervates muscles of the abdominal wall.
The subcostal nerve innervates muscles of the abdominal wall and the skin of the lower abdominal wall.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 17
Correct
-
Which of the following structures carry part of the right bundle branch of the AV bundle?
Your Answer: Moderator band (septomarginal trabecula)
Explanation:The moderator band extends from the base of the anterior papillary muscle to the ventricular septum. It is the structure which carries part of the right AV bundle. Its role it to prevent overdistention of the ventricle.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 18
Correct
-
A 5 year-old-child with fever complains of sore throat . She was brought to her paediatrician for consult because she has also developed a rash and has swollen lymph nodes. Upon physical examination she cried when her liver was palpated and the tip of her spleen is slightly palpable. Full blood count shows haemoglobin 13 g/dL, Haematocrit 40%, white blood cell count 13x109/L with a WBC differential count of 45 neutrophils, 4 bands, 26 lymphocytes, 15 atypical lymphocytesm, 10 monocytes and 1 eosinophil. Whick is the most likely infectious agent that is responsible for the patient's condition?
Your Answer: Epstein–Barr virus
Explanation:Epstein-Barr virus (EBV), also known as human herpes virus 4,is a member of the herpes virus family. EBV spreads most commonly through bodily fluids, primarily saliva. EBV can cause infectious mononucleosis. Symptoms of EBV can include fatigue, fever, inflamed throat, swollen lymph nodes in the neck, enlarged spleen, swollen liver and rash.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 19
Correct
-
Which of the following substances is most likely to cause pulmonary vasodilatation?
Your Answer: Nitric oxide
Explanation:In the body, nitric oxide is synthesised from arginine and oxygen by various nitric oxide synthase (NOS) enzymes and by sequential reduction of inorganic nitrate. The endothelium of blood vessels uses nitric oxide to signal the surrounding smooth muscle to relax, so dilating the artery and increasing blood flow. Nitric oxide/oxygen blends are used in critical care to promote capillary and pulmonary dilation to treat primary pulmonary hypertension in neonatal patients post-meconium aspiration and related to birth defects.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 20
Correct
-
The thyroid gland is a large ductless gland located in which part of the neck?
Your Answer: Visceral space
Explanation:The thyroid gland is an endocrine gland in the neck, consisting of two lobes connected by an isthmus. It is situated at the front and sides of the neck in the visceral space.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 21
Correct
-
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: 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 22
Incorrect
-
A 45-year old lady underwent biopsy of a soft, fleshy mass involving her left breast. The biopsy showed lymphoid stroma with minimal fibrosis, surrounding sheets of large vesicular cells with frequent mitoses. Which condition is she most likely suffering from?
Your Answer: Cystosarcoma phyllodes
Correct Answer: Medullary carcinoma of breast
Explanation:Medullary carcinoma is a malignant tumour of the breast with well-defined boundaries and accounts for 5% of all breast cancers. Other special features include a larger size of the neoplastic cells and presence of lymphoid cells at tumour edge. Differential diagnosis includes invasive ductal carcinoma. Prognosis is usually good.
-
This question is part of the following fields:
- Pathology
- Women's Health
-
-
Question 23
Correct
-
Which among the following vertebrae marks the lowest extent of the superior mediastinum?
Your Answer: Fourth thoracic
Explanation:The superior mediastinum lies between the manubrium anteriorly and the upper vertebrae of the thorax posteriorly. Below, it is bound by a slightly oblique plane that passes backward from the sternal angle to the lower part of the body of T4 and laterally by the pleura.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 24
Correct
-
A 60-year-old female has sudden onset of high-grade fever associated with cough with productive rusty-coloured sputum. Chest x-ray showed left-sided consolidation. What is the most accurate test for the diagnosis of this patient?
Your Answer: Sputum culture
Explanation:Sputum culture is used to detect and identify the organism that are infecting the lungs or breathing passages.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 25
Correct
-
A 56-year old male with history of previous abdominal surgery presents to the emergency department with severe abdominal pain that is increasing in intensity. This pain is associated with abdominal distension and faint, high-pitched bowel sounds. An old scar is also noted on the abdomen. An erect abdominal X-ray shows multiple air-fluid levels in dilated bowel loops. No occult blood was found in stool sample. What is the most likely predisposing factor for his present condition?
Your Answer: Adhesions from previous surgery
Explanation:The described features suggest acute bowel obstruction. The scar described points toward previous surgery, which suggests development of peritoneal adhesions that could lead to obstruction. Hepatitis does not lead to dilated bowel loops. Amoebiasis could lead to inflammatory bowel disease, however, occult blood in stool is usually positive. Ileal adenocarcinoma is rare. Meckel’s diverticulum can possibly lea to obstruction but the findings described here are more consistent with obstruction due to peritoneal adhesions from a past surgery.
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 26
Incorrect
-
What causes a reduction in pulmonary functional residual capacity?
Your Answer: Emphysema
Correct Answer: Pulmonary fibrosis
Explanation:Pulmonary functional residual capacity (FRC) is = volume of air present in the lungs at the end of passive expiration.
Obstructive diseases (e.g. emphysema, chronic bronchitis, asthma) = an increase in FRC due to an increase in lung compliance and air trapping.
Restrictive diseases (e.g. pulmonary fibrosis) result in stiffer, less compliant lungs and a reduction in FRC.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 27
Incorrect
-
Which tumour occurs in young adults, affecting the epiphyses of the bones and sometimes extending to the soft tissues?
Your Answer: Osteoid osteoma
Correct Answer: Benign giant-cell tumour
Explanation:Benign giant-cell tumours tend to affect adults in their twenties and thirties, occur in the epiphyses and can erode the bone and extend into the soft tissues. These tumours have a strong tendency to recur.
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 28
Correct
-
What is the basic chemical reaction that takes place in the breakdown of complex foodstuffs?
Your Answer: Hydrolysis
Explanation:Breakdown of complex food into simpler compounds is achieved by hydrolysis, with the help of different enzymes specific for different compounds.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 29
Correct
-
A 45-year-old woman was brought to the emergency department due to fever and chills. She has a history of recurrent UTI and complains of dysuria and urinary frequency. Urinary white blood cell count is >200 cell/high power field. If urine culture is performed, what is the most likely organism that will grow?
Your Answer: Escherichia coli
Explanation:The pathogen that most likely causes recurrent urinary tract infection in young women are E. coli, Enterococcus and Staphylococcus saprophyticus.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 30
Correct
-
A 35-year old lady presents to her GP with vague abdominal symptoms. Examination reveals a normal size spleen. Which of the following is the likely diagnosis?
Your Answer: Idiopathic thrombocytopenic purpura
Explanation:Idiopathic thrombocytopenic purpura (ITP) is a disease caused due to development of an antibody against a platelet antigen (autoantibody). In childhood disease, the autoantibody gets triggered by binding of viral antigen to the megakaryocytes. Presentation includes unexplained thrombocytopenia, petechiae and bleeding from mucosal surfaces. The spleen usually does not enlarge in size. However, splenomegaly can occur due to coexisting viral infection. Marrow examination reveals normal or increased number of megakaryocytes. Diagnosis is by exclusion of other thrombocytopenic disorders.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 31
Correct
-
A 72 year old man suffered a MI. What is the approximate time needed by the scar tissue of the MI to recover and attain full strength?
Your Answer: Several months
Explanation:A week following a MI attack, a little collagen starts to form and deposit. By the end of the 2nd week, neovascularisation of the scar occurs, with some collagen being laid down in a haphazard fashion. By this time the scar attains some strength. During the next 6 months, collagen is constantly being laid down and is rearranged in order to shrink the scar. Most of the blood vessels by this time have regenerated, decreasing vascularity of the scar reaching full maturity.
-
This question is part of the following fields:
- Cell Injury & Wound Healing; Cardiovascular
- Pathology
-
-
Question 32
Incorrect
-
Both the arytenoid muscles and the lateral cricoarytenoid muscles perform this action on the glottis:
Your Answer: Abduction
Correct Answer: Adduction
Explanation:Both the arytenoid and the cricoartenoid muscles close the glottis. The lateral cricoarytenoid muscles extend from the lateral cricoid cartilage to the muscular process of the arytenoid cartilage. By rotating the arytenoid cartilages medially, these muscles adduct the vocal cords and thereby close the rima glottidis. The arytenoid muscle adducts or approximates the arytenoid cartilages, and thus closes the aperture of the glottis.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 33
Correct
-
A 5-year-old child presents with fever and otalgia. Greenish pustular discharge was seen in his left ear during physical examination. The patient is diagnosed with otitis externa. Which of the following organisms most likely caused the infection?
Your Answer: Pseudomonas aeruginosa
Explanation:P. aeruginosa is a multidrug resistant pathogen recognised for its ubiquity, its advanced antibiotic resistance mechanisms and its association with serious illnesses – especially hospital-acquired infections such as ventilator-associated pneumonia and various septic syndromes. The species name aeruginosa is a Latin word meaning verdigris (copper rust), referring to the blue-green colour of laboratory cultures of the species. This blue-green pigment is a combination of two metabolites of P. aeruginosa, pyocyanin (blue) and pyoverdine (green), which impart the blue-green characteristic colour of cultures.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 34
Correct
-
A patient sustained an injury to the facial nerve after it emerges from the stylomastoid foramen. What is the clinical impact of this injury?
Your Answer: Facial expression
Explanation:The facial nerve is the seventh of the twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla. It controls the muscles of facial expression and supplies taste fibres to the anterior two-thirds of the tongue. It also supplies preganglionic parasympathetic fibres to several head and neck ganglia. Its branches and distribution are as follows:
Inside the facial canal (proximal to the stylomastoid foramen):
– Greater petrosal nerve – provides parasympathetic innervation to the lacrimal gland, as well as special taste sensory fibres to the palate via the nerve of pterygoid canal
– Nerve to stapedius – provides motor innervation for the stapedius muscle in the middle ear
– Chord tympani – provides parasympathetic innervation to the submandibular and sublingual glands and special sensory taste fibres for the anterior two-thirds of the tongue
Outside the skull (distal to the stylomastoid foramen):
– Posterior auricular nerve – controls the movements of some of the scalp muscles around the ear
– Five major facial branches (in the parotid gland), from top to bottom: temporal branch, zygomatic branch, buccal branch, marginal mandibular branch and cervical branch. From the description given above it is obvious that injury to the facial nerve distal to the stylomastoid foramen will affect facial expression.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 35
Correct
-
A 7-year old child from a rural setting complains of recurrent abdominal pain. The child is found to have a heavy parasitic infestation and anaemia. Which type of anaemia is most likely seen in this patient?
Your Answer: Iron deficiency anaemia
Explanation:The most common cause of iron deficiency anaemia in children in developing countries is parasitic infection (hookworm, amoebiasis, schistosomiasis and whipworm).
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 36
Correct
-
Which of the following brings about a reduction in gastric blood flow?
Your Answer: Vasopressin
Explanation:Gastric blood flow is increased by vagal stimulation, gastrin, histamine and acetylcholine as they stimulate gastric section and the production of vasodilator metabolites. Acetylcholine and histamine also have a direct action on the gastric arterioles. Similarly, gastric blood flow is reduced by inhibitors of secretion – catecholamines, secretin and vasopressin.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 37
Incorrect
-
What is the percentage of bone calcium that is freely exchangeable with the extracellular fluid that is available for buffering changes in the calcium ion balance?
Your Answer: 10%
Correct Answer: 1%
Explanation:Around 1% of calcium in the body is available for buffering changes in calcium ion balance. These are mainly derived from the bone that are freely exchangeable with extracellular fluid.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 38
Correct
-
Which antibiotic acts by inhibiting protein synthesis?
Your Answer: Erythromycin
Explanation:Penicillins and cephalosporins (e.g. cefuroxime, cefotaxime, ceftriaxone) inhibit bacterial cell wall synthesis through the inhibition of peptidoglycan cross-linking.
Macrolides (e.g. erythromycin), tetracyclines, aminoglycosides and chloramphenicol act by interfering with bacterial protein synthesis.
Sulphonamides (e.g. trimethoprim, co-trimoxazole) work by inhibiting the synthesis of nucleic acid
-
This question is part of the following fields:
- Pharmacology; Microbiology
- Physiology
-
-
Question 39
Incorrect
-
A 10-year-old boy was sent for an x-ray of the leg because he was complaining of pain and swelling. The x-ray showed the classic sign of Codman's triangle. What is the most likely diagnosis of this patient?
Your Answer: Osteomyelitis
Correct Answer: Osteosarcoma
Explanation:Codman’s triangle is the triangular area of new subperiosteal bone that is created when a lesion, often a tumour, raises the periosteum away from the bone. The main causes for this sign are osteosarcoma, Ewing’s sarcoma, eumycetoma, and a subperiosteal abscess.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 40
Correct
-
Which of the following chemotherapy regimens is most likely to be used in colorectal cancer?
Your Answer: FOLFOX
Explanation:Chemotherapy regimens are often identified by acronyms, identifying the agents used in the drug combination. However, the letters used are not consistent across regimens. FOLFOX is a chemotherapy regimen used for the treatment of colorectal cancer, made up of the following drugs: • FOL: fluorouracil (5-fluorouracil or 5-FU) • F: folinic acid (leucovorin) • OX: oxaliplatin (Eloxatin®).
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 41
Correct
-
Which one of the following muscles is innervated by the facial nerve?
Your Answer: Buccinator
Explanation:Buccinator is a muscle of facial expression and is therefore innervated by the facial nerve. The lateral pterygoid, masseter, anterior belly of digastric and temporalis are all muscles of mastication and therefore innervated by the mandibular division of the trigeminal nerve.
-
This question is part of the following fields:
- Anatomy
- Head & Neck; Neurology
-
-
Question 42
Correct
-
How much blood can the pulmonary vessels of a 45-year-old healthy man accommodate when he is at rest?
Your Answer: 500 ml
Explanation:Pulmonary circulation is the portion of the cardiovascular system which carries deoxygenated blood away from the heart, to the lungs, and returns oxygenated blood back to the heart. The vessels of the pulmonary circulation are very compliant (easily distensible) and so typically accommodate about 500 ml of blood in an adult man. This large lung blood volume can serve as a reservoir for the left ventricle, particularly during periods when left ventricular output momentarily exceeds venous return.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 43
Correct
-
You are asked to help a junior medical student studying anatomy to identify the left lung. Which of the following features found only in the left lung will you use the identify it?
Your Answer: Cardiac notch
Explanation:Oblique fissure: is found on both the left and the right lungs. It separates the upper from the lower lobes in both lungs and the middle lobe from the lower lobe in the right lung(which has three lobes.)
The superior lobar bronchus is found in both lungs.
Cardiac notch: found only on the left lung.
Horizontal fissure: a deep groove separating the middle lobe from the upper lobe of the right lung is absent on the left lung.
Diaphragmatic surface: refers to the part of the lung, both the left and the right, that is in contact with the diaphragm.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 44
Correct
-
A 26-year old man is brought to the A&E with a stab wound to the chest. The wound is in a part of the left lung that might partially fill the costomediastinal recess in full respiration. Where did the weapon strike this man?
Your Answer: Lingula
Explanation:During full inspiration, the lingual-of the left lung partially fills the costomediastinal recess. If the apex of the lung is fully filled with air, it would occupy the copula (the part of the pleura that extends above the first rib). The hilum is part of the lung where the neurovascular structures that form the root of the lung enter and leave the lung and doesn’t expand on inspiration. The middle lobe can expand to fill the costomediastinal recess, however, the middle lobe is on the right lung. The inferior lobe, during full inspiration, might fill the costodiaphragmatic recess.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 45
Correct
-
The absence of which of the following components characterizes the grey platelet syndrome (GPS)?
Your Answer: Alpha granules
Explanation:Grey platelet syndrome (GPS) is a rare inherited bleeding disorder associated with an almost total absence of α-granules and their contents. The syndrome is characterised by thrombocytopenia, enlarged platelets that have a grey appearance, myelofibrosis, and splenomegaly. Alpha granules store proteins and growth factors that promote platelet adhesiveness and wound healing. Patients with GPS develop symptoms and signs such as easy bruising, prolonged bleeding, and nose bleeds.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 46
Incorrect
-
Which of the following substances will enhance the activity of antithrombin III?
Your Answer: Warfarin
Correct Answer: Heparin
Explanation:Antithrombin III is a glycoprotein that inactivates multiple enzymes involved in the coagulation system. It inactivates factor X, factor IX, factor II, factor VII, factor XI and factor XII. Its activity is greatly increased by the action of heparin.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 47
Correct
-
A 27-year-old woman, who had been taking a combined oral contraceptive for 6 months, presented with inguinal pain and oedema of the left leg. Which of the following investigations would you recommend to help confirm the diagnosis?
Your Answer: Duplex scan
Explanation:Oral combined contraceptive pill (OCCP) is a drug used for birth control and treating a number of other conditions. Women who take the OCP have a higher risk of developing deep vein thrombosis (DVT), usually in the legs. Duplex ultrasonography is a safe and non-invasive technique which is used for diagnosing the presence of lower extremity thrombi.
-
This question is part of the following fields:
- Cardiovascular
- Pathology
-
-
Question 48
Incorrect
-
Following an accident, a man was unable to extend the wrist and metacarpophalangeal joints, despite sensation being intact. Which nerve was likely damaged?
Your Answer: Radial nerve
Correct Answer: Posterior interosseous nerve
Explanation:The posterior interosseous nerve which causes, what is known as the posterior interosseous nerve syndrome. The nerve is compressed before it bifurcates to form the medial and lateral branches. The compression is beyond the origin of the branches to the radial wrist extensors and the radial sensory nerve. The result of such a case is paralysis of the digital extensors and the extensor carpi ulnaris, resulting in dorsoradial deviation of the wrist.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 49
Correct
-
Normally, the O2 transfer in the lungs from alveolar to capillary is perfusion-limited. In which of the following situations does it become a diffusion-limited process?
Your Answer: Pulmonary oedema
Explanation:Normally, the transfer of oxygen from air spaces to blood takes place across the alveolar-capillary membrane by simple diffusion and depends entirely on the amount of blood flow (perfusion-limited process). Diseases that affect this diffusion will transform the normal process to a diffusion limited process. Thus, the diseases which cause a thickened barrier (such as pulmonary oedema due to increased extravascular lung water or asbestosis) will limit the diffusion of oxygen. Chronic obstructive lung diseases will have little effect on diffusion. Inhaling hyperbaric gas mixtures might overcome the diffusion limitation in patients with mild asbestosis or interstitial oedema, by increasing the driving force. Strenuous (not mild) exercise might also favour diffusion limitation and decrease passage time. Increasing the rate of ventilation will not have this affect but will only maintain a high oxygen gradient from air to blood.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 50
Correct
-
Which of the following is the cause of flattened (notched) T waves on electrocardiogram (ECG)?
Your Answer: Hypokalaemia
Explanation:The T-wave is formed due to ventricular repolarisation. Normally, it is seen as a positive wave. It can be normally inverted (negative) in V1 (occasionally in V2-3 in African-Americans/Afro-Caribbeans). Hyperacute T-waves are the earliest ECG change of acute myocardial infarction. ECG findings of hyperkalaemia include high, tent-shaped T-waves, a small P-wave and a wide QRS complex. Hypokalaemia results in flattened (notched) T-waves, U-waves, ST-segment depression and prolonged QT interval.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 51
Correct
-
During a laparoscopic surgery, the surgeon visualizes the medical umbilical folds on the deep surface of the anterior abdominal wall. What causes the medial umbilical folds?
Your Answer: Obliterated umbilical arteries
Explanation:The medial umbilical ligament is a structure found on the deep surface of the anterior abdominal wall and is covered by the medial umbilical folds. It is a paired structure that represents the remnants of the fetal umbilical artery. They have no role in humans after birth other than to be used as a landmark for exploring the medial inguinal fossa during laparoscopic inguinal hernia repair.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 52
Correct
-
During gastrectomy, the operating surgeon ligates the short gastric arteries along the greater curvature of the stomach. Where do the short gastric arteries branch from?
Your Answer: Splenic artery
Explanation:Short gastric arteries arise from the splenic artery at the end or from its terminal divisions. They are about 5 or 7 in number, passing from the left to the right in between the layers of the gastrosplenic ligament to be distributed along the greater curvature of the stomach.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 53
Correct
-
During a splenectomy procedure of a 45-year old male patient with a bleeding ruptured spleen, the surgeon decided to clamp the splenic artery near the coeliac trunk to stop the bleeding. Which of the following organ/s parts will be least affected by the clamping?
Your Answer: Duodenum
Explanation:The duodenum is the only organ in the list that would not be affect by the clumping of the splenic artery as it is supplied by common hepatic artery (through the gastroduodenal artery) and the superior mesenteric artery (through the inferior pancreaticoduodenal artery). The splenic artery is the artery that supplies the spleen with oxygenated blood. The splenic artery before reaching the spleen also gives off branches that supply the stomach and the pancreas. The greater curvature and the fundus of the stomach is supplied the short gastric artery which branches off from the splenic artery. The left portion of the greater curvature of the stomach together with the greater omentum is supplied by the left gastro-omental artery of the splenic artery. The body and tail of the pancreas is supplied by branches of the splenic artery through the dorsal and superior pancreatic arteries and the caudal pancreatic arteries respectively.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 54
Correct
-
A 45-year-old man complains of shortness of breath, cough and chest pain. Chest X ray revealed a perihilar mass with bronchiectasis in the left mid-lung. Which of the following is most probably associated with these findings?
Your Answer: Bronchial carcinoid
Explanation:Bronchial carcinoids are neuroendocrine tumours that arise from Kulchitsky’s cells of the bronchial epithelium. Kulchitsky’s cells belong to the diffuse endocrine system. Patients affected by this tumour may be asymptomatic or may present with symptoms of airway obstruction, like dyspnoea, wheezing, and cough. Other common findings are recurrent pneumonia, haemoptysis, chest pain and paraneoplastic syndromes. Chest radiographs are abnormal in the majority of cases. Peripheral carcinoids usually present as a solitary pulmonary nodule. For central lesions common findings include hilar or perihilar masses with or without atelectasis, bronchiectasis, or consolidation. Bronchial carcinoids most commonly arise in the large bronchi causing obstruction.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 55
Correct
-
A 50 year old woman presented with excessive bleeding after an inguinal hernia repair. Labs are suggestive of a primary haemostasis defect. Deficiency of which of the following is most likely to cause it?
Your Answer: Platelets
Explanation:Primary haemostatic control means the first line of defence against immediate bleeding. This is carried out by the platelets. They immediately form a haemostatic plug at the site of injury. Coagulation starts within 20s after an injury to the blood vessel which damage the endothelial cells. Secondary haemostasis follows which includes activation of the coagulation factors to form fibrin strands which mesh together forming the platelet plug. Platelets interact with platelet collagen receptor, glycoprotein Ia/IIa and to collagen fibres in the vascular endothelium. This adhesion is mediated by von Willebrand factor (vWF), which forms links between the platelet glycoprotein Ib/IX/V and collagen fibrils. The platelets are then activated and release the contents of their granules into the plasma, in turn activating other platelets and white blood cells.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 56
Correct
-
The LEAST mobile structure in the peritoneal cavity is the:
Your Answer: Pancreas
Explanation:The presence or absence of the mesentery determines mobility of abdominal contents. Structures like the stomach, transverse colon and appendix have mesenteries and thus are relatively mobile. In contrast, the pancreas is a retroperitoneal (behind the peritoneum) structure and therefore is fixed. The greater omentum is a large mobile fold of omentum that hangs down from the stomach .
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 57
Correct
-
In a neurological exam on a robbery with violence victim, it was discovered that the victim had lost sense of touch to the skin over her cheek and chin (maxilla and mandible region). Where are the cell bodies of the nerve that is responsible for touch sensations of this region located?
Your Answer: Cranial nerve V ganglion
Explanation:The skin over the cheek and the maxilla are innervated by the trigeminal nerve (CN V). The trigeminal nerve has three major branches and it is the largest cranial nerve. The three branches of the trigeminal nerve are; the ophthalmic nerve, the maxillary nerve and the mandibular nerve. The trigeminal nerves ganglion is a sensory nerve ganglion know as the trigeminal ganglion (also referred to as the Gasser’s ganglion or the semilunar ganglion). It is contained in the dura matter in a cavity known as the Meckel’s cave, which covers the trigeminal impression near the apex of the petrous part of the temporal bone.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 58
Correct
-
The muscle that forms the posterior wall of the axilla along with the scapula, subscapularis muscle and teres major muscle is the?
Your 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.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 59
Correct
-
A 30-year old lady was admitted to the general surgical ward after a diagnosis of perforation of the first part of the duodenum that resulted from a long standing ulcer. If this perforation led to the expulsion of the gastric content that resulted to the erosion of an artery found in this part of the duodenum (the posterior of the first part of the duodenum). Which of the following arteries is this most likely to be?
Your Answer: Gastroduodenal
Explanation:The proximal part of the duodenum is supplied by the gastroduodenal artery. This artery is found descending behind the first part of the duodenum after branching from the hepatic artery. If gastric content was to be expelled in the posterior portion of the first part of the duodenum, then this artery would be most likely to be damaged. The common hepatic artery and the left gastric artery are branches of the coeliac trunk that are found superior to the duodenum. The proper hepatic artery is a branch of the common hepatic artery also found superior to the duodenum. The superior mesenteric artery is found behind the pancreas as a branch of the aorta that is at the bottom of the L1 level. The right gastric artery arises above the pylorus from the proper hepatic artery and supplies the lesser curvature of the stomach. The intestinal arteries supply the ileum and the jejunum.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 60
Correct
-
A neonate with failure to pass meconium is being evaluated. His abdomen is distended and X-ray films of the abdomen show markedly dilated small bowel and colon loops. The likely diagnosis is:
Your Answer: Aganglionosis in the rectum
Explanation:Hirschsprung’s disease (also known as aganglionic megacolon) leads to colon enlargement due to bowel obstruction by an aganglionic section of bowel that starts at the anus. A blockage is created by a lack of ganglion cells needed for peristalsis that move the stool. 1 in 5000 children suffer from this disease, with boys affected four times more commonly than girls. It develops in the fetus in early stages of pregnancy. Symptoms include not having a first bowel movement (meconium) within 48 hours of birth, repeated vomiting and a swollen abdomen. Two-third of cases are diagnosed within 3 months of birth. Some children may present with delayed toilet training and some might not show symptoms till early childhood. Diagnosis is by barium enema and rectal biopsy (showing lack of ganglion cells).
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 61
Correct
-
A 30-year old lady presented to her GP with complaints of tremors, excessive emotional outbursts, weight loss and increased sweating over 20 days. On examination, she had warm and moist skin, a fine tremor of the fingers and hyperreflexia. Her vital signs were normal. What is the likely diagnosis?
Your Answer: Hyperthyroidism
Explanation:Excess of circulating free thyroid hormones (thyroxine and/or triiodothyronine) leads to hyperthyroidism. Common causes include Graves’ disease, toxic thyroid adenoma and toxic multinodular goitre. Grave’s disease is the most common cause and is responsible for 70-80% cases of hyperthyroidism. Other causes include excess intake of thyroid hormone, amiodarone-related. It is important that hyperthyroidism is not confused with hyperthyroxinaemia (high levels of thyroid hormone in blood), which includes causes like thyroiditis. Both the conditions lead to thyrotoxicosis (symptoms due to hyperthyroxinemia). Symptoms include weight loss associated with increased appetite, anxiety, weakness, heat intolerance, depression, increased sweating, dyspnoea, loss of libido, diarrhoea, palpitations and occasionally arrhythmias. If there is an acute increase in metabolic rate, the condition is known as ‘thyroid storm’. Elderly sometimes present only with fatigue and weight loss and this is called apathetic hyperthyroidism. Neurological symptoms are also seen in hyperthyroidism and these are tremor, chorea, myopathy and periodic paralysis. One of the most serious complications of hyperthyroidism is stroke of cardioembolic origin due to coexisting atrial fibrillation.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 62
Incorrect
-
If your EEG shows waves with a frequency range of 8-12 Hz, the waves most likely to be seen are:
Your Answer: Delta
Correct Answer: Alpha
Explanation:Electroencephalography (EEG) is the neurophysiological measurement of the electrical activity of the brain. It is done by placing electrodes on the scalp or subdurally. In reality, the electrical currents are not measured, but rather the voltage differences between different parts of the brain. Four major types of EEG activity are recognized, which are alpha, beta, delta and theta.
Alpha waves, also known as Berger’s waves ranges in frequency from 8-12 Hz. Best detected with eyes closed, alpha waves are characteristic of a relaxed, alert state of consciousness. An alpha-like normal variant called mu is sometimes seen over the motor cortex (central scalp) and attenuates with movement or, rather, with the intention to move.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 63
Correct
-
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: 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.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 64
Incorrect
-
The Henderson–Hasselbalch equation describes the derivation of pH as a measure of acidity. According to this equation, the buffering capacity of the system is at maximum when the number of free anions compared with undissociated acid is:
Your Answer: Three times more
Correct Answer: Equal
Explanation:In 1908, Lawrence Joseph Henderson wrote an equation describing the use of carbonic acid as a buffer solution. Later, Karl Albert Hasselbalch re-expressed that formula in logarithmic terms, resulting in the Henderson–Hasselbalch equation. The equation is also useful for estimating the pH of a buffer solution and finding the equilibrium pH in acid–base reactions. Two equivalent forms of the equation are: pH = pKa + log10 [A–]/[HA] or pH = pKa + log10 [base]/[acid]. Here, pKa is − log10(Ka) where Ka is the acid dissociation constant, that is: pKa = –log10(Ka) = –log10 ([H3 O+][A–]/[HA]) for the reaction: HA + H2 O ≈ A– + H3 O+ In these equations, A– denotes the ionic form of the relevant acid. Bracketed quantities such as [base] and [acid] denote the molar concentration of the quantity enclosed. Maximum buffering capacity is found when pH = pKa or when the number of free anions to undissociated acid is equal and buffer range is considered to be at a pH = pKa ± 1.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 65
Correct
-
A 45-year old farmer was referred to the surgical clinic with complaints of pain in his right hypochondrium. Investigations confirmed the diagnosis of hepatocellular carcinoma with malignant ascites. According to you, what is the most likely cause of HCC in this patient?
Your Answer: Aflatoxin
Explanation:Aflatoxins are naturally occurring toxins produced by the Aspergillus fungus (most often, A. flavus and A. parasiticus). These organisms are common and their native habitat is soil, decaying vegetation and grains. They can contaminate the grain before harvest or after storage, more likely in high-humidity (at least 7%) or high temperature environment of after stressful conditions like drought. Aflatoxins are mycotoxins and also carcinogenic. They get metabolized in the liver to an epoxide, aflatoxin M1. High exposure can lead to acute necrosis, cirrhosis or liver carcinoma. These substances can cause haemorrhage, acute liver damage, oedema, and alteration in digestion, absorption and/or metabolism of nutrients. Although humans are susceptible to these toxins like all other animals, they have a high tolerance level and hence, rarely develop acute aflatoxicosis. However, children are particularly susceptible to exposure leading to growth impairment and delayed development. Chronic exposure carries a high risk of hepatic cancer, due to intercalation of its metabolite aflatoxin M1 into the DNA and alkylation of the bases because of its epoxide moiety.
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 66
Correct
-
Atractyloside is an inhibitor of electron transport chain. It is expected to have little or no effect on the functioning of which of the following cell types?
Your Answer: Red blood cells
Explanation:Electron transport chain is a series of electron carriers that are embedded in the mitochondrial membrane. It is the place where ATP is made. Inhibiting the electron transport chain will stop production of ATP. Red blood cells are the only cell in the given option which do not contain ATP.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 67
Incorrect
-
A 35 year old man presented to the surgical OPD with a lump on his right forearm which appeared 3 weeks ago and was tender on examination. He gave a history was being in a car accident with pieces of glass from the windshield piercing his forearm removed manually and on further elective surgery. Which of these cells are characteristically found during inflammation in this situation?
Your Answer: Plasma cell
Correct Answer: Giant cell
Explanation:A foreign body reaction Is characteristic of giant cells. Glass being the foreign object initiates an inflammatory response in this condition.
Mast cells are involved in allergic reactions.
Eosinophils are characteristic of a parasitic infection and allergic inflammatory process but are not due to foreign bodies.
Plasma cells are typical of chronic inflammation.
Lymphocytes are involved in viral infections.
Macrophages combine together to form giant cells.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 68
Correct
-
Pseudomonas aeruginosa is a multidrug resistant pathogen that causes hospital-acquired infections. It is usually treated with piperacillin or another antibiotic. Which of the following is the other antibiotic?
Your Answer: Azlocillin
Explanation:Azlocillin, like piperacillin, is an acylampicillin antibiotic with an extended spectrum of activity and greater in vitro potency than the carboxypenicillins. Azlocillin is similar to mezlocillin and piperacillin. It demonstrates antibacterial activity against a broad spectrum of bacteria, including Pseudomonas aeruginosa.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 69
Correct
-
The superior pancreaticoduodenal artery, the artery that supplies blood to the pancreas and the duodenum, is a branch of the:
Your Answer: Gastroduodenal artery
Explanation:The superior pancreaticoduodenal artery together with the right gastroepiploic artery form the two branches of the gastroduodenal artery which divides at the lower border of the duodenum.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 70
Correct
-
In a hypertensive patient with secondary hyperaldosteronism, aldosterone is released mainly in response to:
Your Answer: Angiotensin II
Explanation:Secondary hyperaldosteronism in hypertension is either due to primary renin overproduction by the kidneys or renin overproduction secondary to decreased renal blood flow. The main stimulus for aldosterone release are adrenocorticotrophic hormone (ACTH), angiotensin II and high plasma K+ levels. Low plasma Na+ might also stimulate the adrenal cortex. Fluid overload will reduce aldosterone secretion. Atrial natriuretic peptide is secreted under conditions of expanded extracellular volume and will not lead to aldosterone secretion.
-
This question is part of the following fields:
- Endocrinology
- Physiology
-
-
Question 71
Incorrect
-
A significantly elevated white cell count of 50 x 109/l with 5% blasts and raised leucocyte alkaline phosphatase is seen in which of the following conditions?
Your Answer: Acute myelogenous leukaemia
Correct Answer: Leukaemoid reaction
Explanation:Non-neoplastic proliferation of leucocytes causes an increase in leukocyte alkaline phosphatase (LAP). This is referred to as ‘leukemoid reaction’ because of the similarity to leukaemia with an increased white cell count (>50 × 109/l) with immature forms. Causes of leukemoid reaction includes haemorrhage, drugs (glucocorticoids, all-trans retinoic acid etc), infections such as tuberculosis and pertussis, and as a paraneoplastic phenomenon. Leukemoid reaction can also be seen in infancy as a feature of trisomy 21. This is usually a benign condition, but can be a response to a disease state. Differential diagnosis include chronic myelogenous leukaemia (CML).
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 72
Correct
-
Which organs would cause pain in a patient who complains of dull pain in her pelvis, along the midline starting from the pubic bone in the front to the sacrum at the back?
Your Answer: Urinary bladder, uterus/cervix/vagina, rectum
Explanation:The pain could have been caused by the urinary bladder, uterus/cervix/vagina or rectum as it involves the pelvic viscera.
-
This question is part of the following fields:
- Anatomy
- Pelvis
-
-
Question 73
Correct
-
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: 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.
-
This question is part of the following fields:
- Neurology
- Pathology
-
-
Question 74
Correct
-
A 58-year-old woman diagnosed with deep vein thrombosis had been using warfarin for 10 days. When she presented to the doctor she had haemorrhagic bullae and necrotic lesions in her lower limbs and buttocks. Deficiency of which of the following proteins may have caused the necrotic skin lesions?
Your Answer: Protein C
Explanation:Warfarin-induced skin necrosis is a rare complication of anticoagulant therapy that requires immediate drug cessation. The most common cutaneous findings include petechiae that progress to ecchymoses and haemorrhagic bullae. Warfarin inactivates vitamin K-dependent clotting factors II, VII, IX, and X and vitamin K-dependent proteins C and S. The concentration of protein C falls more rapidly than other vitamin K-dependent factors because they have a shorter half-lives. Skin necrosis is seen mainly in patients with prior protein C deficiency.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 75
Correct
-
The lateral thoracic artery:
Your Answer: Accompanies the long thoracic nerve to the serratus anterior muscle
Explanation:The thoracic nerve, along with the lateral thoracic artery, follow the pectoralis minor to the side of the chest which supplies the serratus anterior and the pectoralis. It then sends branches across the axilla to the axillary glands and subscapularis. The pectoral branch of the thoraco-acromial anastomoses with the internal mammary, subscapular and intercostal arteries, which in women, supply an external mammary branch.
-
This question is part of the following fields:
- Anatomy
- Breast
-
-
Question 76
Correct
-
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: 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.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 77
Incorrect
-
The vagus nerve passes through which of the following foramen?
Your Answer: Foramen magnum
Correct Answer: Jugular foramen
Explanation:The jugular foramen is a large foramen in the base of the skull. It is located behind the carotid canal and is formed in front by the petrous portion of the temporal bone, and behind by the occipital bone. Cranial nerves IX, X, and XI and the internal jugular vein pass through the jugular foramen.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 78
Correct
-
On exploration of an axillary wound, a branch from the third part of the axillary artery was found to be transected. Which of the following arteries would have been likely injured?
Your Answer: Anterior circumflex humeral
Explanation:The axillary artery gives off many branches from the first, second, or third parts along its course. The third part of the axillary artery gives off 3 branches: the subscapular, anterior and posterior circumflex humeral arteries.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 79
Correct
-
A 45-year old gentleman presented to the emergency department at 5.00 AM with pain in his left flank. The pain began suddenly and presented in waves throughout the night. Urine examination was normal except for presence of blood and few white blood cells. The pH and specific gravity of the urine were also found to be within normal range. What is the likely diagnosis?
Your Answer: Ureteric calculus
Explanation:A calculus in the ureter, if less than 5mm in diameter is likely to pass spontaneously. However, a larger calculus irritates the ureter and may become lodged, leading to hydroureter and/or hydronephrosis. Likely sites where the calculus might get lodged, include pelviureteric junction, distal ureter at the level of iliac vessels and the vesicoureteric junction. An obstruction can result in reduced glomerular filtration. There can be deterioration in renal function due to hydronephrosis and a raised glomerular pressure, leading to poor renal blood flow. Permanent renal dysfunction usually takes about 4 weeks to occur. Secondary infection can also occur in chronic obstruction.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 80
Correct
-
Which of the following structure contains the parasympathetic pre-ganglionic nucleus that innervates the iris sphincter muscle and the ciliary muscle?
Your Answer: Edinger–Westphal nucleus
Explanation:The Edinger–Westphal nucleus (accessory oculomotor nucleus) is the parasympathetic pre-ganglionic nucleus that innervates the iris sphincter muscle and the ciliary muscle.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 81
Correct
-
Which of the following is the most accurate test for the diagnosis of primary syphilis?
Your Answer: Dark-field microscopy
Explanation:Primary syphilis is transmitted via sexual contact. Lesions on genitalia, called a chancre occur after an asymptomatic incubation period of 10-90 days (average 21 days) after exposure. This chancre is a typically solitary (can be multiple), firm, painless, ulceration over the skin at the point of exposure to spirochete, seen on penis, vagina or rectum. It heals spontaneously after 4-6 weeks. Local lymphadenopathy can be seen.
Diagnosis is made by microscopy of fluid from lesion using dark-field illumination, taking care to not confuse with other treponemal disease. Screening tests include rapid plasma regain (RPR) and Venereal Diseases Research Laboratory (VDRL) tests. False positives are known to occur with these tests and can be seen in viral infections like hepatitis, varicella, Epstein-Barr virus, tuberculosis, lymphoma, pregnancy and IV drug use. More specific tests should therefore be carried out in case these screening tests are positive.
The Treponema pallidum hemagglutination assay (TPHA) and the fluorescent treponemal antibody absorption (FTAABS) test are based on monoclonal antibodies and immunofluorescence and are more specific. However, they can too show false positives with other treponemal diseases like yaws or pinta. Other confirmatory tests include those based on enzyme-linked immunoassays.
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 82
Correct
-
The fundus of the stomach receives blood supply from the same artery as the greater curvature of the stomach. Which of the following arteries when ligated will disrupt blood supply to the fundus of the stomach through this artery?
Your Answer: Splenic
Explanation:The fundus of the stomach along with the greater curvature of the stomach receive blood supply from the short gastric artery. The short gastric artery arises from the end of the splenic artery. The ligation of the splenic artery therefore would cause a disruption of blood supply to the fundus of the stomach.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 83
Correct
-
Which of the following is true about a patient who has undergone total colectomy and ileostomy?
Your Answer: Following total colectomy and ileostomy, the volume and water content of ileal discharge decreases over time
Explanation:After a patient has undergone total colectomy and ileostomy, the volume of ileal discharge, along with its water content gradually decreases over time. Post surgery, most patients can live a normal life. Iron and vitamin B12 absorption do not take place in the colon and hence are not affected significantly by a colectomy.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 84
Correct
-
The midgut loop, also called the primary intestinal loop in a developing embryo, is formed when the midgut bends around which of the following arteries?
Your Answer: Superior mesenteric
Explanation:In a developing foetus, the midgut develops to form most of the intestines. During this development process, the midgut usually bends around the superior mesenteric artery and forms what is referred to as the midgut loop.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 85
Incorrect
-
Which of the following will be affected by a lesion in the posterior column-medial lemniscus system?
Your Answer: Hearing
Correct Answer: Fine touch
Explanation:The posterior column–medial lemniscus (PCML) pathway is a sensory pathway that transmits fine touch and conscious proprioceptive information from the body to the brain. As the posterior columns are also known as dorsal columns, the pathway is also called the dorsal column–medial lemniscus system or DCML.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 86
Incorrect
-
During routine laboratory tests, a 66-year-old man is found to be suffering from hypercholesterolaemia and is prescribed atorvastatin. What is the mechanism of action of atorvastatin?
Your Answer: Inhibits lipoprotein lipase
Correct Answer: Inhibits cholesterol synthesis
Explanation:Atorvastatin is a member of the drug class of statins, used for lowering cholesterol. The mode of action of statins is inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. This enzyme is needed by the body to make cholesterol. The primary uses of atorvastatin is for the treatment of dyslipidaemia and the prevention of cardiovascular disease.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 87
Correct
-
A 62-year-old woman presented to the doctor complaining of spine pain, fatigue and oliguria. She is diagnosed with chronic renal failure. Dipstick testing shows no protein, glucose, nitrite or ketones but a semi-quantitative sulphosalicylic acid test for urine protein is positive. Which of the following is the most probable cause of chronic renal failure in this patient.
Your Answer: Multiple myeloma
Explanation:Dipstick results are negative because the proteins found in the urine of this patient are not albumin but Bence Jones proteins. A Bence Jones protein is a monoclonal globulin protein commonly detected in patients affected by multiple myeloma. Multiple myeloma is a malignancy of plasma cells characterised by the production of monoclonal immunoglobulin. Symptoms include bone pain, bone fractures, bleeding, neurologic symptoms, fatigue, frequent infections and weight loss.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 88
Correct
-
A man was stabbed in the thigh following a bar brawl. A superficial vein was injured which terminates in the femoral vein. This superficial vein is?
Your Answer: Great saphenous
Explanation:The great saphenous vein is considered the longest vein in the body. It terminates in the femoral vein nearly 3cm below the inguinal ligament. It begins at the dorsum of the foot in the medial marginal vein and ascends at the medial side of the leg in relation with the saphenous nerve.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 89
Correct
-
A patients sciatic nerve has been severed following a stab injury. What would be affected?
Your Answer: There would still be cutaneous sensation over the anteromedial surface of the thigh
Explanation:The sciatic nerve supplies nearly all of the sensation of the skin of the leg and the muscles of the back of the thigh, leg and foot. A transection of the sciatic nerve at its exit from the pelvis will affect all the above-mentioned functions except cutaneous sensation over the anteromedial surface of the thigh, which comes from the femoral nerve.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 90
Correct
-
A 90-year-old man is prescribed spironolactone after his family notices his legs are swollen. What class of drugs does spironolactone belong to?
Your Answer: Potassium-sparing diuretics
Explanation:Spironolactone is a renal competitive aldosterone antagonist in a class of drugs called ‘potassium-sparing diuretics’, that is primarily used to treat fluid build-up due to heart failure, liver scarring, or kidney disease. It is also used in the treatment of high blood pressure, low blood potassium, early-onset puberty, and acne and excessive hair growth in women. Spironolactone inhibits the effect of aldosterone by competing for intracellular aldosterone receptors in the distal tubule cells. This increases the secretion of water and sodium, while decreasing the excretion of potassium.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 91
Correct
-
A patient under went repair of a lingual artery aneurysm in the floor of the mouth. During surgical dissection from the inside of the mouth which muscle would you have to pass through to reach the main portion of the lingual artery?
Your Answer: Hyoglossus
Explanation:The lingual artery first runs obliquely upward and medialward to the greater horns of the hyoid bone. It then curves downward and forward, forming a loop which is crossed by the hypoglossal nerve, and passing beneath the digastric muscle and stylohyoid muscle it runs horizontally forward, beneath the hyoglossus, and finally, ascending almost perpendicularly to the tongue, turns forward on its lower surface as far as the tip, to become the deep lingual artery.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 92
Correct
-
Injury to this nerve may result in loss of sensation of the mandibular teeth and bone:
Your Answer: Inferior alveolar nerve
Explanation:The inferior alveolar nerve (sometimes called the inferior dental nerve) is a branch of the mandibular nerve, which is itself the third branch of the trigeminal nerve. The inferior alveolar nerves supply sensation to the lower teeth of the mandible.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 93
Correct
-
Passing through the lesser sciatic foramen are the:
Your Answer: Pudendal nerve
Explanation:Structures that pass through the lesser sciatic foramen include:
– the pudendal nerve
– the nerve to obturator internus
– internal pudendal artery
– the tendon of obturator internus
-
This question is part of the following fields:
- Anatomy
- Pelvis
-
-
Question 94
Correct
-
A 23-year-old woman decides to donate a kidney through a kidney chain. Which of the following indices would be expected to be decreased in the donor after full recovery from the operation?
Your Answer: Creatinine clearance
Explanation:Since medication to prevent rejection is so effective, donors do not need to be similar to their recipient. Most donated kidneys come from deceased donors; however, the utilisation of living donors is on the rise. Most problems encountered with live donation are associated with the donor. Firstly, there are the potentially harmful investigative procedures carried out in the assessment phase, the most hazardous being renal angiography, where there is cannulation of the artery and injection of a radio-opaque dye to determine the blood supply to the kidney. Secondly, there are the short-term risks of nephrectomy surgery. According to the literature, there is a mortality rate of between 1 in 1600 and 1 in 3000, but this is no more than is associated with any anaesthetic. In the initial postoperative period creatinine clearance may be decreased but this recovers fully over a few weeks to months. Long-term complications include prolonged wound pain.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 95
Correct
-
The blood investigations of a 30-year old man with jaundice revealed the following : total bilirubin 6.5 mg/dl, direct bilirubin 1.1 mg/dl, indirect bilirubin 5.4 mg/dl and haemoglobin 7.3 mg/dl. What is the most likely diagnosis out of the following?
Your Answer: Haemolysis
Explanation:Hyperbilirubinemia can be caused due to increased bilirubin production, decreased liver uptake or conjugation, or decreased biliary excretion. Normal bilirubin level is less than 1.2 mg/dl (<20 μmol/l), with most of it unconjugated. Elevated unconjugated bilirubin (indirect bilirubin fraction >85%) can occur due to haemolysis (increased bilirubin production) or defective liver uptake/conjugation (Gilbert syndrome). Such increases are less than five-fold usually (<6 mg/dl or <100 μmol/l) unless there is coexistent liver disease.
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 96
Correct
-
Which of the following physiological changes will you see in a young man who has been trekking in the Himalayas for 3 years?
Your Answer: Increased renal excretion of HCO3 –
Explanation:The atmospheric pressure is lower at high altitudes as compared with sea level. This leads to a decrease in the partial pressure of oxygen. Once 2100 m (7000 feet) of altitude is reached, there is a drop in saturation of oxyhaemoglobin. The oxygen saturation of haemoglobin determines the oxygen content in the blood. The body physiological tries to adapt to high altitude by acclimatization. Immediate effects include hyperventilation, fluid loss (due to a decreased thirst drive), increase in heart rate and slightly lowered stroke volume. Long term effects include lower lactate production, compensatory alkali loss in urine, decrease in plasma volume, increased erythropoietin release and red cell mass, increased haematocrit, higher concentration of capillaries in striated muscle tissue, increase in myoglobin, increase in mitochondria, increase in aerobic enzyme concentration such as 2,3-DPG and pulmonary vasoconstriction.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 97
Correct
-
A 27-year old lady is shot in the chest. The bullet enters superior to the upper edge of the clavicle. She had difficulty in breathing which is interpreted by the A&E physician as a likely indicator of a collapsed lung. If that is the case, what portion of the pleura is most likely to have been punctured?
Your Answer: Cupola
Explanation:The cupola is part of the pleura that extends above the first rib into the root of the lung. Most likely to injured in a stab above the level of the clavicle.
Costodiaphragmatic recess: the lowest extent of the pleural sac.
Pulmonary ligament: is a fold of pleura located below the root of the lung.
Mediastinal pleura: part of the pleura that lines the mediastinal cavity.
Hilar reflection is the part of the pleura where the visceral pleura of the lung reflects to become continuous with the parietal pleura.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 98
Correct
-
Digital rectal examination of a 75-year old gentleman who presented to the surgical clinic with urinary retention revealed an enlarged, nodular prostate. PSA was found to be elevated, favouring the diagnosis of prostatic malignancy. Which of the given options is the most common malignant lesion affecting the prostate gland?
Your Answer: Adenocarcinoma
Explanation:Prostatic adenocarcinoma is the commonest solid malignancy and non-dermatological cancer in men above 50 years age. Increasing in incidence with age and the highest risk seen in the black population. About 75% of cases are seen in men over 65 years. Other tumours affecting the prostate include undifferentiated prostate cancer, squamous cell carcinoma, and ductal transitional carcinoma, but these occur less commonly. Sarcomas usually affect children. Hormones play a role in the aetiology of prostate adenocarcinoma unlike the other types. Intraepithelial neoplasia is considered a precursor of invasive malignancy.
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 99
Correct
-
Paracentesis of ascetic fluid in a 45-year old woman revealed the following : clear, yellow fluid with protein 2.0 g/dl and a few mesothelial and mononuclear cells seen. No malignant cells seen. What is the likely diagnosis?
Your Answer: Cirrhosis
Explanation:Ascites develops either from:
-
- Increased  accumulation
- Increased capillary permeability
- Increased venous pressure
- Decreased protein (oncotic pressure)
- Decreased clearance
- Increased lymphatic obstruction
- Increased  accumulation
Cause
- Transudate (<30g/L protein) (Systemic disease)
- Liver (Cirrhosis)
- Cardiac e.g. RHF, CCF, SBE right heart valve disease and constrictive Pericarditis
- Renal failure
- Hypoalbuminaemia (nephrosis)
- Exudate (>30g/L protein) (Local disease)
- Malignancy
- Venous obstruction e.g. Budd-Chiari, Schistosomiasis
- Pancreatitis
- Lymphatic obstruction
- Infection (especially TB)
Cirrhosis is disease of the liver that is characterized by fibrosis leading to disorganization of the hepatic architecture. It shows the development of regenerative nodules surrounded by dense fibrotic tissue. Cirrhosis shows non-specific symptoms initially, which include fatigue, anorexia and weight loss. It can later progress to portal hypertension, ascites and liver failure.
-
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 100
Incorrect
-
Evaluation of a 60-year old gentleman, who has been a coal miner all his life and is suspected to have pulmonary fibrosis reveals the following: FEV1 of 75% (normal > 65%), arterial oxygen saturation 92%, alveolar ventilation 6000 ml/min at a tidal volume of 600 ml and a breathing rate of 12 breaths/min. There are also pathological changes in lung compliance and residual volume. Calculate his anatomical dead space.
Your Answer: 500 ml
Correct Answer: 100 ml
Explanation:Dead space refers to inhaled air that does not take part in gas exchange. Because of this dead space, taking deep breaths slowly is more effective for gas exchange than taking quick, shallow breaths where a large proportion is dead space. Use of a snorkel by a diver increases the dead space marginally. Anatomical dead space refers to the gas in conducting areas such as mouth and trachea, and is roughly 150 ml (2.2 ml/kg body weight). This corresponds to a third of the tidal volume (400-500 ml). It can be measured by Fowler’s method, a nitrogen wash-out technique. It is posture-dependent and increases with increase in tidal volume. Physiological dead space is equal to the anatomical dead space plus the alveolar dead space, where alveolar dead space is the area in the alveoli where no effective exchange takes place due to poor blood flow in capillaries. This physiological dead space is very small normally (< 5 ml) but can increase in lung diseases. Physiological dead space can be measured by Bohr’s method. Total ventilation per minute (minute ventilation) is given by the product of tidal volume and the breathing rate. Here, the total ventilation is 600 ml times 12 breaths/min = 7200 ml/min. The problem mentions alveolar ventilation to be 6000 ml/min. Thus, the difference between the alveolar ventilation and total ventilation is 7200 – 6000 ml/min = 1200 ml/min, or 100 ml per breath at 12 breaths per min. This 100 ml is the dead space volume.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
SESSION STATS - PERFORMANCE PER SPECIALTY
