-
Question 1
Correct
-
A 49-year-old woman with acute renal failure has a total plasma [Ca2+] = 2. 5 mmol/l and a glomerular filtration rate of 160 l/day. What is the estimated daily filtered load of calcium?
Your Answer: 240 mmol/day
Explanation:Calcium is the most abundant mineral in the human body. The average adult body contains in total approximately 1 kg of calcium of which 99% is in the skeleton in the form of calcium phosphate salts. The extracellular fluid (ECF) contains approximately 22 mmol, of which about 9 mmol is in the plasma. About 40% of total plasma Ca2+ is bound to proteins and not filtered at the glomerular basement membrane. Therefore, the estimated daily filtered load is 1.5 mmol/l × 160 l/day = 240 mmol/day. The exact amount of free versus total Ca2+ depends on the blood pH: free Ca2+ increases during acidosis and decreases during alkalosis.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 2
Incorrect
-
After a car accident, a 30-year-old woman is alert and only has minor, superficial injuries. 2 hours later, she becomes unconscious and a CT scan reveals a convex, lens-shaped haemorrhage over the right parietal region. The most likely diagnosis is:
Your Answer: Subarachnoid haemorrhage
Correct Answer: Epidural haematoma
Explanation:Epidural haematomas are usually caused by arterial bleeding, classically due to damage to the middle meningeal artery by a temporal bone fracture. Symptoms develop within minutes to several hours after the injury and consist of increasing headache, decreased level of consciousness, hemiparesis and pupillary dilation with loss of light reactivity. Around 15–20% of epidural hematomas are fatal.
-
This question is part of the following fields:
- Neurology
- Pathology
-
-
Question 3
Incorrect
-
A 77-year-old woman's renal function is tested. The following results were obtained during a 24-h period:
Urine flow rate: 2. 0 ml/min
Urine inulin: 0.5 mg/ml
Plasma inulin: 0.02 mg/ml
Urine urea: 220 mmol/l
Plasma urea: 5 mmol/l.
What is the urea clearance?Your Answer: 320 ml/min
Correct Answer: 88 ml/min
Explanation:Urea is reabsorbed in the inner medullary collecting ducts of the nephrons. The clearance (C) of any substance can be calculated as follows: C = (U × V)/P, where U and P are the urine and plasma concentrations of the substance, respectively and V is the urine flow rate. So, glomerular filtration rate = (0.220 × 2. 0)/0.005 = 88 ml/min.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 4
Correct
-
An operation to resect a tumour of the right lung was stopped as the chest surgeon said that the tumour was crossing the oblique fissure. Which structures are separated by the oblique fissure of the right lung?
Your Answer: Lower lobe from both upper and middle lobes
Explanation:The oblique fissure on the right lung separates the lower lobe from both the middle and upper lobe. The lingual is only found on the left lung and is part of the upper lobe.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 5
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 6
Correct
-
Which of the following muscles attaches to the pterygomandibular raphe?
Your Answer: Superior pharyngeal constrictor muscle
Explanation:The pterygomandibular raphé (pterygomandibular ligament) provides attachment on its posterior border to the superior pharyngeal constrictor and on its anterior border to the buccinator muscle.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 7
Correct
-
A 50-year old gentleman who suffered a stroke was brought to the emergency department by his relatives. The patient however denied the presence of paralysis of his left upper and lower limbs. What is the most likely site of the lesion in this patient?
Your Answer: Right posterior parietal cortex
Explanation:A large injury to the non-dominant parietal cortex can make the patient neglect or refuse to acknowledge the presence of paralysis on the contralateral side. This can also involve the perception of the external world. Smaller injuries in this area which involve the precentral gyrus (primary motor cortex) or postcentral gyrus (primary sensory cortex) cause contralateral spastic paralysis or contralateral loss of tactile sensation respectively. A lesion in posterior inferior gyrus of the dominant frontal lobe results in motor aphasia. Involvement of the posterior superior gyrus of the dominant frontal lobe produces sensory aphasia.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 8
Correct
-
A 4-year-old child was brought to a paediatrician for consult due to a palpable mass in his abdomen. The child has poor appetite and regularly complains of abdominal pain. The child was worked up and diagnosed with a tumour. What is the most likely diagnosis ?
Your Answer: Nephroblastoma
Explanation:Nephroblastoma is also known as Wilms’ tumour. It is a cancer of the kidneys that typically occurs in children. The median age of diagnose is approximately 3.5 years. With the current treatment, approximately 80-90% of children with Wilms’ tumour survive.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 9
Incorrect
-
A 25 year-old male patient was brought to the hospital due to a vehicular accident. A skull x-ray was done which revealed a fracture along the base of the middle cranial fossa. The patient has no sense of touch over the skin over his cheek and chin. Injury to the maxillary and the mandibular nerves is suspected. In which foramina do these two affected sensory branches leave the cranial cavity.
Your Answer: Superior orbital fissure and foramen rotundum
Correct Answer: Foramen rotundum and foramen ovale
Explanation:The patient’s clinical manifestations suggests an injury to the maxillary and mandibular nerves. The maxillary branch (V2) of the trigeminal nerve (CN V) passes through and exits the skull via the pterygopalatine fossa and the foramen rotundum. At the base of the skull the foramen ovale (Latin: oval window) is one of the larger of the several holes (the foramina) that transmit nerves through the skull. The foramen ovale is situated in the posterior part of the sphenoid bone, posterolateral to the foramen rotundum. The following structures pass through foramen ovale: mandibular nerve, motor root of the trigeminal nerve, accessory meningeal artery (small meningeal or paradural branch, sometimes derived from the middle meningeal artery), lesser petrosal nerve, a branch of the glossopharyngeal nerve and an emissary vein connecting the cavernous sinus with the pterygoid plexus of veins. Occasionally it will also carry the anterior trunk of the middle meningeal vein.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 10
Incorrect
-
A 42 - year old male patient with an acute onset headache was brought in to the emergency department with suspicion of a subarachnoid haemorrhage (SAH). The SHO on call decided to have a diagnostic lumbar puncture after computed topography scan failed to support the suspicion. To perform a successful lumbar puncture without causing injury to the spine, which anatomical landmark should guide the SHO to locate the fourth vertebra for insertion of the spinal needle?
Your Answer: Iliac tuberosity
Correct Answer: Iliac crest
Explanation:The safest spinal level for conducting a lumbar puncture, is at the level of the fourth lumbar vertebra. The anatomical landmark used to locate the fourth lumbar vertebra (L4), is the iliac crest. The needle can safely be inserted either above or below L4. The conus medullaris is at the level of the border of L1 and L2 so L4 is safely distant from it.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 11
Incorrect
-
During cardiac catheterisation, if the blood sample from the catheter shows an oxygen saturation of 70%, and the pressure ranging from 12 to 24 mm Hg, it implies that the catheter tip is located in the:
Your Answer: Foramen ovale
Correct Answer: Pulmonary artery
Explanation:Normal values for various parameters are as follows:
Systolic arterial blood pressure (SBP): 90–140 mmHg.
Diastolic arterial blood pressure: 60–90 mmHg.
Mean arterial blood pressure (MAP): SBP + (2 × DBP)/3 (normal range: 70-105 mmHg).
Right atrial pressure (RAP): 2–6 mmHg.
Systolic right ventricular pressure (RVSP): 15–25 mmHg.
Diastolic right ventricular pressure (RVDP): 0–8 mmHg.
Pulmonary artery pressure (PAP): Systolic (PASP) is 15-25 mmHg and Diastolic (PADP) is 8–15 mmHg.
Pulmonary artery wedge pressure (PAWP): 6–12 mmHg.
Left atrial pressure (LAP): 6–12 mmHg.
Thus, the given value indicates that the position of catheter tip is likely to be in the pulmonary artery.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 12
Incorrect
-
After total thyroidectomy, which of the following investigations is recommended in the immediate post-operative period?
Your Answer: Antithyroglobulin antibody
Correct Answer: Serum calcium
Explanation:Total thyroidectomy might sometimes result in inadvertent excision or damage of parathyroid glands, leading to hypoparathyroidism. Monitoring serum calcium levels in the post-operative period to detect hypocalcaemia is essential to diagnose and prevent this condition.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 13
Incorrect
-
A specialist registrar was performing the bi-lateral surgical removal of the adrenal glands. He first removed the left adrenal gland before moving on to the right one. However, the registrar noticed that the removal of the right adrenal gland would be a challenge because of an overlying structure. What was this structure that overlies the right suprarenal glad?
Your Answer:
Correct Answer: Inferior vena cava
Explanation:The adrenal glands or the suprarenal glands are small glands that are found on top of each of the kidneys. They are retroperitoneal glands. The right adrenal gland is found on top of the right kidney and is closely associated with the inferior vena cava as it directly drains into this large vein. In the case where the right adrenal gland is to be surgically removed, the inferior vena cava might prove a problem to manoeuvre as it overlies the right suprarenal gland. The other blood vessels such as the aorta, right renal, superior mesenteric, splenic artery and the hepatic vein as well as the right crus are not closely associated with either of the suprarenal glands.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 14
Incorrect
-
The principal motor and sensory nerve of the perineum is the?
Your Answer:
Correct Answer: Pudendal
Explanation:The pudendal nerve is formed by S1,2,4 anterior branches. It gives off the inferior haemorrhoid nerve before dividing terminally into the perineal nerve and the dorsal nerve of the clitoris or the penis. Thus, it is the principal motor and sensory nerve of the perineum.
-
This question is part of the following fields:
- Anatomy
- Pelvis
-
-
Question 15
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:
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 16
Incorrect
-
Which of these foramen is located at the base of the skull and transmits the accessory meningeal artery?
Your Answer:
Correct Answer: Foramen ovale
Explanation:At the base of the skull the foramen ovale is one of the larger of the several holes that transmit nerves through the skull. The following structures pass through foramen ovale: mandibular nerve, motor root of the trigeminal nerve, accessory meningeal artery, lesser petrosal nerve, a branch of the glossopharyngeal nerve, emissary vein connecting the cavernous sinus with the pterygoid plexus of veins and occasionally the anterior trunk of the middle meningeal vein.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 17
Incorrect
-
Which cells are most commonly seen in a granulomatous lesion that suggests an underlying chronic inflammation?
Your Answer:
Correct Answer: Lymphocytes
Explanation:Lymphocytes and monocytes are commonly and characteristically recognised in a case of chronic inflammation.
Eosinophils and neutrophils are seen with acute inflammation.
Mast cells release histamine in early inflammation.
Basophils are seen with allergies.
Plasma cells are seen with viral infection.
Platelets are not characteristic of any type of inflammation.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 18
Incorrect
-
A 70-year old man presents to the surgical out patient clinic with a direct inguinal hernia on the right side. He had undergone and appendicectomy 6 months prior. The examining doctor correlated the development of the hernia to iatrogenic nerve injury that happened during the operation. Which nerve had been injured?
Your Answer:
Correct Answer: Ilioinguinal
Explanation:Direct inguinal hernias occur because of weakness in the abdominal muscles. The ilioinguinal nerve is important for innervating the muscles of the lower abdominal wall and damage during appendicectomy therefore prevents the man from being able to contract abdominal muscles to pull the falx inguinalis over the weak fascia.
The genitofemoral nerve innervates the cremaster muscle and injury to it would cause inability to elevate the testes.
The subcostal nerve and the ventral primary ramus of T10 innervate the muscles, skin and fascia of the upper abdominal wall.
The iliohypogastric nerve supplies the skin over the upper part of the buttock behind the area supplied by the subcostal nerve.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 19
Incorrect
-
A 72-year-old male presents with dysuria and chronic haematuria. He was diagnosed with bladder cancer and tumour invasion of the perivesical fat. What is the stage of the patient's bladder cancer?
Your Answer:
Correct Answer: T3
Explanation:Bladder cancer is the growth of abnormal or cancerous cells on the inner lining of the bladder wall. The staging is as follows; stage 0is (Tis, N0, M0): Cancerous cells in the inner lining tissue of the bladder only, stage I (T1, N0, M0): tumour has spread onto the bladder wall, stage II (T2, N0, M0): tumour has penetrated the inner wall and is present in muscle of the bladder wall, stage III (T3, N0, M0): tumour has spread through the bladder to fat around the bladder and stage IV: (T4, N0, M0): tumour has grown through the bladder wall and into the pelvic or abdominal wall. The stage of cancer in the case presented is T3 because of the invasion of perivesical fat.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 20
Incorrect
-
An 80 year-old quadriplegic man has been lying supine for 7 weeks in a critical care ward. He develops a right lung abscess that is draining by gravity to a particular region of the lung. Which is the most likely site of pus collection?
Your Answer:
Correct Answer: Superior segment of the lower lobe
Explanation:The superior segmental bronchus of the lower lobe of the right lung branches posteriorly off the intermediate bronchus or the inferior lobe bronchus. It is therefore more likely to receive fluid or foreign bodies that enter the right main bronchus especially when the patient is supine.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 21
Incorrect
-
An abdominal aortogram shows occlusion of the inferior mesenteric artery. Which of the following segments of bowel is most likely to have preserved arterial supply?
Your Answer:
Correct Answer: Caecum
Explanation:The inferior mesenteric artery supplies blood to the end of the transverse colon and all distal structures in the gastrointestinal tract i.e. splenic flexure, descending colon, sigmoid colon and rectum would all be deprived of blood if it were occluded. The caecum receives blood from the superior mesenteric artery so it would not be affected.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 22
Incorrect
-
Vincristine is a chemotherapy agent used to treat a number of types of cancer. Which of the following is a recognised major side-effect of vincristine?
Your Answer:
Correct Answer: Peripheral neuropathy
Explanation:Vincristine is an alkaloid chemotherapeutic agent. It is used to treat a number of types of cancer including acute lymphocytic leukaemia, acute myeloid leukaemia, Hodgkin’s disease, neuroblastoma, and small cell lung cancer among others. The main side-effects of vincristine are peripheral neuropathy and constipation.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 23
Incorrect
-
From which of the following cells is heparin produced?
Your Answer:
Correct Answer: Mast cells
Explanation:Heparin is a natural highly-sulphated glycosaminoglycan that has anticoagulant functions. It is produced by the body basophils and mast cells.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 24
Incorrect
-
A 59-year-old man was brought to the emergency department by his family after complaining of sudden, severe upper back pain and a ripping sensation, that radiated to his neck. On arrival, his pulse was weak in one arm compared with the other however his ECG result was normal. Which of the following is most probably the cause of these findings and symptoms?
Your Answer:
Correct Answer: Acute aortic dissection
Explanation:Acute aortic dissection is a serious condition in which the inner layer of the aorta tears and the blood flows in between the inner and middle layers of the aorta causing their separation (dissection). Aortic dissection can lead to rupture or decreased blood flow to organs. Clinical manifestations most often include the sudden onset of severe, tearing or ripping chest pain that can radiate to the shoulder, back or neck; syncope; altered mental status; dyspnoea; pale skin; stroke symptoms etc. The diagnosis of acute aortic dissection is based on clinical findings, imaging studies, electrocardiography and laboratory analysis.
-
This question is part of the following fields:
- Cardiovascular
- Pathology
-
-
Question 25
Incorrect
-
A 39-year-old man, after radiological evaluation and thoracentesis, was found to have chylothorax. What is the most probable cause of this diagnose?
Your Answer:
Correct Answer: Mediastinal malignant lymphoma
Explanation:Chylothorax is a potentially lethal condition characterized by fluid (chyle) accumulation in the pleural cavity, resulting from disruption of lymphatic drainage in the thoracic duct. Chyle is a fluid rich in triglycerides and chylomicrons and can originate from the thorax, the abdomen or both. Malignant tumours, especially lymphoma, are the most common causes of nontraumatic chylothorax. Bronchogenic carcinoma and trauma are the most common causes after lymphomas. Other rare causes of chylothorax are; granulomatous diseases, tuberculosis, congenital malformations, nephrotic syndrome, hypothyroidism, cirrhosis, decompensated heart failure and idiopathic chylothorax.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 26
Incorrect
-
Epstein-Barr virus (EBV) is known to be a carcinogen for:
Your Answer:
Correct Answer: B-cell lymphoma
Explanation:EBV is known to be carcinogenic for B-cell lymphoma, nasopharyngel carcinoma and Hodgkin’s lymphoma.
-
This question is part of the following fields:
- Microbiology; Neoplasia
- Pathology
-
-
Question 27
Incorrect
-
A 15-day old baby was brought to the emergency department with constipation for 4 days. On examination, the abdomen of the baby was found to be distended and tender all over. No bowel sounds were heard. A sigmoid colon biopsy was carried out, which showed absent ganglion cells. What is the diagnosis?
Your Answer:
Correct Answer: Hirschsprung’s disease
Explanation:Hirschsprung’s disease is characterized by congenital absence of the autonomic plexus (Meissner’s and Auerbach’s plexus) in the intestinal wall. Usually limited to the distal colon, it can occasionally involve the entire colon or even the small bowel. There is abnormal or absent peristalsis in the affected segment, resulting in continuous spasm of smooth muscle and partial/complete obstruction. This causes accumulation of intestinal contents and dilatation of proximal segment. Skip lesions are highly uncommon. This disease is seen early in life with 15% patients presenting in first month, 60% by 1 year of age and 85% by the age of 4 years. Symptoms include severe and complete constipation, abdominal distension and vomiting. Patients with involvement of ultra-short segments might have mild constipation with intervening diarrhoea. In older children, symptoms include failure to thrive, anorexia, and lack of an urge to defecate. On examination, an empty rectum is revealed with stool palpable high up in the colon. If not diagnosed in time, it can lead to Hirschsprung’s enterocolitis (toxic megacolon), which can be fulminant and lead to death. Diagnosis involves a barium enema or a rectal suction biopsy. Barium enema shows a transition in diameter between the dilated, normal colon proximal to the narrowed, affected distal segment. It is to be noted that barium enema should be done without prior preparation, which can dilate the abnormal segment, leading to a false-negative result. A 24-hour post-evacuation film can be obtained in the neonatal period – if the colon is still filled with barium, there is a high likelihood of Hirschsprung’s disease. Full-thickness rectal biopsy is diagnostic by showing the absence of ganglion cells. Acetylcholinesterase staining can be done to highlight the enlarged nerve trunks. Abnormal innervation can also be demonstrated by rectal manometry.
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 28
Incorrect
-
The muscle which has an antagonistic action to the serratus anterior muscle and is one of the retractors of the scapula is the?
Your Answer:
Correct Answer: Rhomboid major
Explanation:Protraction is accomplished by the actions of the serratus anterior, pectoralis major, and pectoralis minor muscles. Retraction is accomplished by the actions of the trapezius, rhomboids, and latissimus dorsi muscles.
The rhomboid major arises from the second, third, fourth and fifth thoracic vertebrae. It is inserted into a narrow tendinous arch attached to the root of the spine of the scapula and the inferior angle. By its insertion in the inferior angle of the scapula, it acts on this angle and produces a slight rotation of the scapula on the side of the chest. It also retracts the scapula by working with the trapezius muscle.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 29
Incorrect
-
A 56-year-old woman weighs 75 kg. In this patient, total body water, intracellular fluid and extracellular fluid are respectively:
Your Answer:
Correct Answer: 45 l, 30 l, 15 l
Explanation:The percentages of body water contained in various fluid compartments add up to total body water (TBW). This water makes up a significant fraction of the human body, both by weight and by volume. The total body water (TBW) content of humans is approximately 60% of body weight. Two-thirds is located in the intracellular and one-third in the extracellular compartment. So, in a 75-kg individual, TBW = 60 × 75/100 = 45 l. Intracellular content = 2/3 × 45 = 30 l and extracellular content = 1/3 × 45 = 15 l.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 30
Incorrect
-
Which muscle would be affected most following injury to the transverse cervical artery?
Your Answer:
Correct Answer: Trapezius
Explanation:The latissimus dorsi receives blood from the thoracodorsal artery, the supraspinatus receives its blood from the suprascapular artery, the levator scapulae and the rhomboids are supplied by the dorsal scapular artery and the transverse cervical artery supplies blood to the trapezius.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 31
Incorrect
-
During an operation to repair an aortic coarctation in a neonate, a surgeon accidentally cuts the first aortic intercostal arteries as he mobilised the descending aorta. Which one of the following structure might be deprived of its primary source of blood supply following this injury?
Your Answer:
Correct Answer: Right bronchus
Explanation:The right bronchus is supplied by one right bronchial artery that may branch from one of the left bronchial arteries or from the right 3rd posterior intercostal artery (this is the first intercostal artery that arises from the aorta). Damage to this artery might stop blood supply to the main bronchus. Intercostal arteries that go to the first and the second interspaces originate from the highest intercostal artery such that blood supply to either of these spaces would not be interfered with.
The left bronchus receives blood from 2 left bronchial arteries which are direct branches from the descending aorta.
Fibrous pericardium is the sac that contains the heart. Its blood supply is not a major concern.
Visceral pericardium receives its blood supply from the coronary vessels.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 32
Incorrect
-
The anatomical course of the phrenic nerve passes over the following muscle in the neck?
Your Answer:
Correct Answer: Anterior scalene
Explanation:The phrenic nerve originates in the neck between C3-C5, mostly C4 spinal root. It enters the thoracic cavity past the heart and lungs to the diaphragm. In the neck, this nerve begins at the lateral border of the anterior scalene muscle, its course then continues inferiorly on the anterior aspect of the anterior scalene muscle as it moves towards the diaphragm.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 33
Incorrect
-
A 54 year old man fell off his bicycle. He felt a severe pain in his hand and wasn't able to move it. It was found that a carpal bone in the distal row was fractured. Which is the most likely bone?
Your Answer:
Correct Answer: Trapezium
Explanation:There are eight carpal bones which are arranged in two rows, proximal and distal; scaphoid, lunate, triquetral and pisiform are of proximal row. Trapezium, trapezoid, capitate and hamate are of the distal row.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 34
Incorrect
-
A 78-year-old man who has been bedridden for a month is prescribed griseofulvin. What class of drugs does griseofulvin belong to?
Your Answer:
Correct Answer: Antifungal
Explanation:Griseofulvin is an antifungal drug. It is administered orally, and it is used to treat ringworm infections of the skin and nails. It binds to keratin in keratin precursor cells and makes them resistant to fungal infections. Griseofulvin works by interfering with fungal mitosis.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 35
Incorrect
-
In the glomerulus of the kidney, the mesangium is a structure associated with the capillaries. It has extraglomerular mesangial cells that:
Your Answer:
Correct Answer: Form the juxtaglomerular apparatus in combination with the macula densa and juxtaglomerular cells
Explanation:The mesangium is an inner layer of the glomerulus, within the basement membrane surrounding the glomerular capillaries. The mesangial cells are phagocytic and secrete the amorphous basement membrane-like material known as the mesangial matrix. They are typically separated from the lumen of the capillaries by endothelial cells. The other type of cells in the mesangium are the extraglomerular mesangial cells which form the juxtaglomerular apparatus in combination with two other types of cells: the macula densa of the distal convoluted tubule and juxtaglomerular cells of the afferent arteriole. This apparatus controls blood pressure through the renin–angiotensin–aldosterone system.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 36
Incorrect
-
Which organ is responsible for the secretion of enzymes that aid in digestion of complex starches?
Your Answer:
Correct Answer: Pancreas
Explanation:α-amylase is secreted by the pancreas, which is responsible for hydrolysis of starch, glycogen and other carbohydrates into simpler compounds.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 37
Incorrect
-
the action of the semimembranosus muscle is:
Your Answer:
Correct Answer: Extension of the hip and flexion of the knee
Explanation:the semimembranosus is situated at the back and medial side of the thigh. It arises from the upper and outer impression on the tuberosity of the ischium, above and lateral to the biceps femoris and semitendinosus. It is inserted mainly into the horizontal groove on the posterior medial aspect of the medial condyle of the tibia. it flexes the knee and assists in extension of the hip.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 38
Incorrect
-
An experiment was conducted in which the skeletal muscle protein (not smooth muscle) involved in contraction was selectively inhibited. Which protein was inhibited?
Your Answer:
Correct Answer: Troponin
Explanation:The mechanism of contraction of smooth muscles is different from that of skeletal muscles in which the contractile protein is troponin whilst in smooth muscle contraction is a protein called calmodulin. Calmodulin reacts with calcium ions and stimulates the formation of myosin crossbridges.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 39
Incorrect
-
Which of these HLA alleles is most likely to be present in ankylosing spondylitis?
Your Answer:
Correct Answer: HLA-B27
Explanation:Ankylosing spondylitis usually appears between the ages of 20-40 years old and is more frequent in men. It is strongly associated with HLA-B27, along with other spondyloarthropathies, which can be remembered through the mnemonic PAIR (Psoriasis, Ankylosing spondylitis, Inflammatory bowel disease, and Reactive arthritis).
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 40
Incorrect
-
Which of the following substances is most likely to cause pulmonary vasodilatation?
Your Answer:
Correct 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 41
Incorrect
-
A 50 year old female patient with an history of chronic headache was scheduled for CT scan. If the CT scan revealed a tumour at the horn of the lateral ventricle, which of the following structures is most likely to be compressed by this tumour?
Your Answer:
Correct Answer: Fibres of the corpus callosum
Explanation:The ventricular system of the brain is made up of four ventricles namely; two lateral and a third and forth ventricle. The ventricles are the site of the development of the cerebrospinal fluid. The left and right lateral ventricles are located in each of the brain’s hemispheres. The roof of the lateral ventricles are made up of the fibres of the corpus callosum. This is the structure that would be compressed by the a tumour on the roof of the lateral ventricles.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 42
Incorrect
-
Loperamide is a drug used to treat diarrhoea. What is the mechanism of action of loperamide?
Your Answer:
Correct Answer: Opiate agonist
Explanation:Loperamide is an opioid-receptor agonist and acts on the mu opioid receptors in the myenteric plexus of large intestine. It works by decreasing the motility of the circular and longitudinal smooth muscles of the intestinal wall. It is often used for this purpose in gastroenteritis, inflammatory bowel disease, and short bowel syndrome.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 43
Incorrect
-
Regarding the venous drainage of the heart which of these is correct?
Your Answer:
Correct Answer: The great cardiac vein is the largest tributary of the coronary sinus and this vein starts at the apex of the heart and ascends with the anterior ventricular branch of the left coronary artery
Explanation:Most of the veins of the heart open into the coronary sinus. This is a wide venous channel, about 2.25 cm in length, situated in the posterior part of the coronary sulcus and covered by muscular fibres from the left atrium. Its tributaries are the great, small and middle cardiac veins, the posterior vein of the left ventricle and the oblique vein of the left atrium. The great cardiac vein is the largest tributary of the coronary sinus.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 44
Incorrect
-
In what form are fats primarily transported in the body?
Your Answer:
Correct Answer: Free fatty acids
Explanation:Fat is mainly transported in the body as free fatty acids. Once out of the adipose cell, the free fatty acids get ionized and combine with albumin.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 45
Incorrect
-
Which is the most common benign germ-cell tumour that could occur in a premenopausal woman?
Your Answer:
Correct Answer: Dermoid cyst
Explanation:A dermoid cyst is a teratoma of a cystic nature that contains an array of developmentally mature and solid tissues. Dermoid cysts grow slowly and this type of cystic teratoma is nearly always benign.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 46
Incorrect
-
A 78-year-old diabetic man undergoes renal function tests. Which of the following substances will be the most accurate for measuring glomerular filtration rate (GFR)?
Your Answer:
Correct Answer: Inulin
Explanation:Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal glomerular capillaries into the Bowman’s capsule per unit time. Clinically, this is often measured to determine renal function. Inulin was originally used as it is not reabsorbed by the kidney after glomerular filtration, therefore its rate of excretion is directly proportional to the rate of filtration of water and solutes across the glomerular filter. However, in clinical practice, creatinine clearance is used to measure GFR. Creatinine is an endogenous molecule, synthesised in the body, that is freely filtered by the glomerulus (but also secreted by the renal tubules in very small amounts). Creatinine clearance exceeds GFR due to creatinine secretion, and is therefore a close approximation of the GFR.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 47
Incorrect
-
Structures passing through the foramen magnum do NOT include the:
Your Answer:
Correct Answer: Vagus nerve
Explanation:Structures passing through the foramen magnum include the medulla, meninges, tectorial membrane, anterior spinal artery, vertebral artery and spinal branches of the accessory nerve.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 48
Incorrect
-
Carbon dioxide is principally transported in the blood in which form?
Your Answer:
Correct Answer: Bicarbonate
Explanation:Carbon dioxide is transported in the blood in various forms:
– Bicarbonate (80–90%)
– Carbamino compounds (5–10%)
– Physically dissolved in solution (5%).
Carbon dioxide is carried on the haemoglobin molecule as carbamino-haemoglobin; carboxyhaemoglobin is the combination of haemoglobin with carbon monoxide.
-
This question is part of the following fields:
- Physiology
- Respiratory; Cardiovascular
-
-
Question 49
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:
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 50
Incorrect
-
Which of the following morphological characteristic is a salient feature of a pure apoptotic cell?
Your Answer:
Correct Answer: Chromatin condensation
Explanation:Apoptosis is the programmed death of cells which occurs as a normal and controlled part of an organism’s growth or development. The changes which occur in this process include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, chromosomal DNA fragmentation, and global mRNA decay. The cell membrane however remains intact and the dead cells are phagocytosed prior to any content leakage and thus inflammatory response.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 51
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:
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 52
Incorrect
-
The optic foramen, superior orbital fissure, foramen ovale, foramen rotundum and foramen sinosum are all located on which bone at the base of the skull?
Your Answer:
Correct Answer: Sphenoid
Explanation:The sphenoid bone consists of two parts, a central part and two wing-like structures that extend sideways towards each side of the skull. It forms the base of the skull, and floor and sides of the orbit. On its central part lies the optic foramen. The foramen ovale, foramen spinosum and foramen rotundum lie on its great wing while the superior orbital fissure lies on its lesser wing.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 53
Incorrect
-
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:
Correct 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 54
Incorrect
-
A 30 year old man suffered severe blood loss, approx. 20-30% of his blood volume. What changes are most likely seen in the pulmonary vascular resistance (PVR) and pulmonary artery pressure (PAP) respectively following this decrease in cardiac output?
Your Answer:
Correct Answer: Increase Decrease
Explanation:Hypovolemia will result in the activation of the sympathetic adrenal discharge resulting is a decrease pulmonary artery pressure and an elevated pulmonary vascular resistance.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 55
Incorrect
-
How are amino acids transported across the luminal surface of the small intestinal epithelium?
Your Answer:
Correct Answer: Co-transport with sodium ions
Explanation:Once complex peptides are broken down into amino acids by the peptidases present in the brush border of small intestine, they are ready for absorption by at least four sodium-dependent amino acid co-transporters – one each for acidic, basic, neutral and amino acids, present on the luminal plasma membrane. These transporters first bind sodium and can then bind the amino acids. Thus, amino acid absorption is totally dependent on the electrochemical gradient of sodium across the epithelium. The basolateral membrane in contrast, possesses additional transporters to carry amino acids from the cell into the blood, but these are sodium-independent.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 56
Incorrect
-
The accumulation of eosinophils within tissues is mostly regulated by which of the following cytokines?
Your Answer:
Correct Answer: Interleukin-5
Explanation:IL-5 is produced by TH2 helper cells and by mast cells. They stimulate increased secretion of immunoglobulins and stimulate B cell growth. They are the major regulators in eosinophil activation and control. They are also released from eosinophils and mast cells in asthmatic patients and are associate with a many other allergic conditions.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 57
Incorrect
-
Hormones of the anterior pituitary include which of the following?
Your Answer:
Correct Answer: Prolactin
Explanation:The anterior pituitary gland (adenohypophysis or pars distalis) synthesizes and secretes:
1. FSH (follicle-stimulating hormone)
2. LH (luteinizing hormone)
3. Growth hormone
4. Prolactin
5. ACTH (adrenocorticotropic hormone)
6. TSH (thyroid-stimulating hormone).
The posterior pituitary gland (neurohypophysis) stores and secretes 2 hormones produced by the hypothalamus:
1. ADH (antidiuretic hormone or vasopressin)
2. Oxytocin
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 58
Incorrect
-
A 15-day old male baby was brought to the emergency department with sweating and his lips turning blue while feeding. He was born full term. On examination, his temperature was 37.9°C, blood pressure 75/45 mmHg, pulse was 175/min, and respiratory rate was 42/min. A harsh systolic ejection murmur could be heard at the left upper sternal border. X-ray chest showed small, boot-shaped heart with decreased pulmonary vascular markings. He most likely has:
Your Answer:
Correct Answer: Tetralogy of Fallot
Explanation:The most common congenital cyanotic heart disease and the most common cause of blue baby syndrome, Tetralogy of Fallot shows four cardiac malformations occurring together. These are ventricular septal defect (VSD), pulmonary stenosis (right ventricular outflow obstruction), overriding aorta (degree of which is variable), and right ventricular hypertrophy. The primary determinant of severity of disease is the degree of pulmonary stenosis. Tetralogy of Fallot is seen in 3-6 per 10,000 births and is responsible for 5-7% congenital heart defects, with slightly higher incidence in males. It has also been associated with chromosome 22 deletions and DiGeorge syndrome. It gives rise to right-to-left shunt leading to poor oxygenation of blood. Primary symptom is low oxygen saturation in the blood with or without cyanosis at birth of within first year of life. Affected children ay develop acute severe cyanosis or ‘tet spells’ (sudden, marked increase in cyanosis, with syncope, and may result in hypoxic brain injury and death). Other symptoms include heart murmur, failure to gain weight, poor development, clubbing, dyspnoea on exertion and polycythaemia. Chest X-ray reveals characteristic coeur-en-sabot (boot-shaped) appearance of the heart. Treatment consists of immediate care for cyanotic spells and Blalock–Taussig shunt (BT shunt) followed by corrective surgery.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 59
Incorrect
-
Which of the following malignancies is likely to have the best prognosis?
Your Answer:
Correct Answer: Papillary carcinoma of the thyroid
Explanation:Papillary carcinoma accounts for 70-80% of all thyroid cancers and is seen commonly in people aged 30-60 years. It is more aggressive in elderly patients. 10-20% cases may have recurrence or persistent disease. More common in females with a female to male ratio of 3:1. Papillary carcinomas can also contain follicular carcinomas. The common route of spread is through lymphatics to regional nodes in one-third cases and pulmonary metastasis can also occur. Papillary carcinomas of the thyroid have the best prognosis, especially in patients less than 45 years of age with small tumours confined to the thyroid gland.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 60
Incorrect
-
A 55-year-old male has a mass on the right lung with involvement of the right mediastinal lymph nodes. What is the nodal staging according to the TNM staging?
Your Answer:
Correct Answer: N2
Explanation:The N stages for lung cancer are from NO to N3 : NO, there is no lung cancer in any lymph nodes: N1, there is lung cancer in the proximal lymph nodes: N2, there is lung cancer in the mediastinal hilar lymph nodes, but on the same side as the affected lung or there is lung cancer in the carinal lymph nodes: N3, there is metastatic lung cancer in lymph nodes on the opposite side of the chest, in the cervical or apical lymph nodes. In this patient the ipsilateral mediastinal node is involved, thus it is classified as N2.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 61
Incorrect
-
Which of the following morphological features is most characteristic of hyaline degeneration?
Your Answer:
Correct Answer: Homogeneous, ground-glass, pink-staining appearance of cells
Explanation:The characteristic morphological features of hyaline degeneration is ground-glass, pinking staining cytoplasm with an intact cell membrane. The accumulation of lipids, calcium salts, lipofuscin and an amorphous cytoplasm with an intact cell membrane are all characteristically found in different situations.
Pyknotic nucleus and orphan Annie eye nucleus are not seen in hyaline degeneration.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 62
Incorrect
-
Regarding the long head of the biceps femoris, which of the following is correct?
Your Answer:
Correct Answer: It crosses two joints
Explanation:The long head of the biceps femoris arises from the lower and inner impression on the back of the tuberosity of the ischium. It inserts with the short head in an aponeurosis which becomes a tendon and this tendon is inserted into the lateral side of the head of the fibula and the lateral condyle of the tibia, thus crossing two joints.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 63
Incorrect
-
A 50 year old man was admitted to the surgical ICU following a hemicolectomy for carcinoma of the caecum. A full blood count revealed: haematocrit = 30%, erythrocytes = 4 × 106/μ, haemoglobin level = 8 g/dl. To determine the likely cause of his anaemia, red blood cell indices were calculated. Which RBC indices are correct?
Your Answer:
Correct Answer: MCHC = haemoglobin concentration/haematocrit
Explanation:Mean corpuscular haemoglobin concentration (MCHC) is calculated simply by dividing the haemoglobin concentration (8 g/dl) by the haematocrit (0.3). The normal range is 31–36 g/dl. This patient has a hypochromic anaemia (MCHC = 8/0.3 = 26.7 g/dl). Dividing the haemoglobin concentration × 10 by erythrocyte number yields mean corpuscular haemoglobin (MCH). Normal range is 25.4–34.6 pg/cell and this patient has a significantly reduced cellular haemoglobin content (MCH = 8 × 10/4 = 20 pg/cell). Mean corpuscular volume (MCV) is calculated by dividing haematocrit × 1000 by erythrocyte number (4 × 106/μl). Normal range is 80–100 fl and this patient has a microcytic anaemia (MCV = 0.3 × 1000/4 = 75 fl). Microcytic, hypochromic anaemia is characteristic for iron-deficiency.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 64
Incorrect
-
During uterogrowth, the second pharyngeal arch gives rise to which structures?
Your Answer:
Correct Answer: Stylohyoid muscle
Explanation:The second pharyngeal arch or hyoid arch, is the second of six pharyngeal arches that develops in fetal life during the fourth week of development and assists in forming the side and front of the neck. Derivatives:
Skeletal – From the cartilage of the second arch arises:
Stapes,
Temporal styloid process,
Stylohyoid ligament, and
Lesser cornu of the hyoid bone.
Muscles:
Muscles of face
Occipitofrontalis muscle
Platysma
Stylohyoid muscle
Posterior belly of Digastric
Stapedius muscle
Auricular muscles
Nerve supply: Facial nerve
-
This question is part of the following fields:
- Anatomy
- Embryology
-
-
Question 65
Incorrect
-
What is the most likely cause of prolonged bleeding time in a 40 year old women admitted for a laparoscopic cholecystectomy?
Your Answer:
Correct Answer: Thrombocytopaenia
Explanation:Bleeding time is related to platelet function, thus a decrease in platelet function, as seen in thrombocytopenia, DIC and von Willebrand disease in which platelet aggregation is defective, leads to an increase in bleeding time. It is not affected by a decrease or deficiency of any other clotting factors. Aspirin and other COX inhibitors prolong bleeding time along with warfarin and heparin.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 66
Incorrect
-
The transmembrane proteins responsible for resting membrane potential of vascular smooth muscle cells was blocked by a drug. Which of the following transmembrane proteins were blocked by this drug?
Your Answer:
Correct Answer: K+ channels
Explanation:The resting membrane potential is due to selective permeability of the membrane to potassium ions. The Na/K pump is responsible for the generation of a gradient across the membrane and it is due to the inherent ability of the K channels to allow diffusion back into the nerve at rest which charges the cells. In reality, the resting membrane potential is more positive because of small contributions by Na+ channels, Cl− channels and non-selective cation channels.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 67
Incorrect
-
During an OSCE exam a medical student is asked to locate the sternal angle. The sternal angle is a land mark for locating the level of the:
Your Answer:
Correct Answer: Second costal cartilage
Explanation:The sternal angle, a key landmark used in the clinic for auscultating for heart sounds, is the point of attachment of the costal cartilage of rib 2 to the sternum. It thus corresponds to the location of the second rib. A horizontal plane through the sternal angle traverses the T4/T5 intervertebral disc and marks the inferior boundary of the superior mediastinum.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 68
Incorrect
-
Question 69
Incorrect
-
There are several mechanisms involved in the transport of sodium ions from blood to interstitial fluid of the muscle cells. Which of the following mechanisms best describes this phenomenon?
Your Answer:
Correct Answer: Diffusion through channels between endothelial cells
Explanation:Capillaries are the smallest of the body’s blood vessels, measuring 5–10 μm and they help to enable the exchange of water, oxygen, carbon dioxide, and many other nutrients and waste substances between the blood and the tissues surrounding them. The walls of capillaries are composed of only a single layer of cells, the endothelium. Ion channels are pore-forming proteins that help to establish and control the small voltage gradient that exists across the plasma membrane of all living cells by allowing the flow of ions down their electrochemical gradient. An ion channel is an integral membrane protein or more typically an assembly of several proteins. The archetypal channel pore is just one or two atoms wide at its narrowest point. It conducts a specific ion such as sodium or potassium and conveys them through the membrane in single file.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 70
Incorrect
-
Calculate the resistance of the artery if the pressure at one end is 60 mmHg, pressure at the other end is 20 mm Hg and the flow rate in the artery is 200 ml/min.
Your Answer:
Correct Answer: 0.2
Explanation:Flow in any vessel = Effective perfusion pressure divided by resistance, where effective perfusion pressure is the mean intraluminal pressure at the arterial end minus the mean pressure at the venous end. Thus, in the given problem, resistance = (60 − 20)/200 = 0.2 mmHg/ml per min.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
