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Question 1
Correct
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Different portions of the renal tubule have varying degrees of water permeability. Which of the following renal sites is characterised by low water permeability under normal circumstances?
Your Answer: Thick ascending limb of the loop of Henlé
Explanation:Within the nephron of the kidney, the ascending limb of the loop of Henle is a segment of the loop of Henle downstream of the descending limb, after the sharp bend of the loop. Both the thin and the thick ascending limbs of the loop of Henlé have very low permeability to water. Since there are no regulatory mechanisms to alter its permeability, it remains poorly permeable to water under all circumstances. Sodium and chloride are transported out of the luminal fluid into the surrounding interstitial spaces, where they are reabsorbed. Water must remain behind because it is not reabsorbed, so the solute concentration becomes less and less (the luminal fluid becomes more dilute). This is one of the principal mechanisms (along with diminution of ADH secretion) for the production of a dilute, hypo-osmotic urine (water diuresis).
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This question is part of the following fields:
- Physiology
- Renal
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Question 2
Correct
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During a procedure in the mediastinum, the surgeon accidentally injured a key structure that lies immediately anterior to the thoracic duct. Which structure is likely to be injured?
Your Answer: Oesophagus
Explanation:In the mid-thorax, the azygos vein, thoracic duct and aorta (in this order from right to the left) are all located posterior to the oesophagus. The superior vena cava, left internal jugular vein and trachea are not found in the mid thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 3
Correct
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A 17-year-old boy, who had developed shortness of breath and a loss of appetite over the last month, was referred to a haematologist because he presented with easy bruising and petechiae. His prothrombin time, platelet count, partial thromboplastin and bleeding time were all normal. Which of the following would explain the presence of the petechiae and easy bruising tendency?
Your Answer: Scurvy
Explanation:Scurvy is a condition caused by a dietary deficiency of vitamin C, also known as ascorbic acid. Humans are unable to synthesize vitamin C, therefore the quantity of it that the body needs has to come from the diet. The presence of an adequate quantity of vitamin C is required for normal collagen synthesis. In scurvy bleeding tendency is due to capillary fragility and not coagulation defects, therefore blood tests are normal.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 4
Incorrect
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The circle of Willis is an arterial anastomosis in the base of the brain and is one of the cerebrovascular safeguards in the brain. Where is the circle of Willis contained?
Your Answer: Cisterna chiasmatis
Correct Answer: Cisterna basalis
Explanation:Cisterns refers to a system of intercommunicating pools formed by the subarachnoid space at the base of the brain and around the brainstem. Cisterna basalis/basal cistern (interpeduncular cistern) is found at the base of the brain between the two temporal lobes and it contains the arterial circle of Willis. The lumbar cistern is contained in the spinal canal while the foramen magna refers to the opening at the base of the skull though which the spinal cord enters into the skull.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 5
Correct
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Which of the following associations is correctly matched with the body's defence mechanism in fighting infection?
Your Answer: Specific cellular mechanism → cytotoxic T cells
Explanation:The immune system has certain levels of defence against pathogens. First line includes simple barriers such as skin, mucosa and stomach acid that prevent the pathogen from entering into the body. If this barrier is breached then the innate immune system is activated which includes leukocytes (macrophages, neutrophils, mast cells, eosinophils, basophils, natural killer cells). If the pathogens invade the second layer of defence then the third layer, adaptive immunity is activated, which includes B and T lymphocytes. B cells provide a humoral response whereas cytotoxic T cells have specific cellular mechanisms. They maintain a memory of past infections and are activated faster following a recurrence.
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This question is part of the following fields:
- General
- Physiology
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Question 6
Incorrect
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The orbicularis oculi us a muscle that closes the eyelids. What is the motor innervation of this muscle?
Your Answer: A branch of the same nerve that innervates the orbicularis oris muscle
Correct Answer: A branch of a nerve that exits through the stylomastoid foramen
Explanation:The orbicularis oculi is a muscle in the face that closes the eyelids. It is supplied by zygomatic branch of the facial nerve (cranial nerve VII), which exits through the stylomastoid foramen.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 7
Correct
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A 13-year-old boy's mother notices he has a lump in his arm, near his right shoulder. An X-ray reveals a lateral projection in the metaphyseal region of his humerus. The lesion is removed and it is found to be composed of bony cortex, capped by cartilage. What's the most likely diagnosis in this case?
Your Answer: Osteochondroma
Explanation:Osteochondromas, or osteocartilaginous exostoses, are the most common benign bone tumours, and tend to appear near the ends of long bones. The overgrowth can occur in any bone where cartilage forms bone, and they are capped by cartilage. They are most common in people between the ages of 10-20 years old.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 8
Correct
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A 38-year old lady presented to the hospital with abnormal passing of blood per vagina. On examination, she was found to have an endocervical polypoidal mass. On enquiry, she gave history of oral contraceptive usage for 3 years. What finding is expected on the histopathology report of biopsy of the mass?
Your Answer: Microglandular hyperplasia
Explanation:Endocervical polyps or microglandular hyperplasia are benign growths occurring in the endocervical canal, in about 2-5% women and occur secondary to use of oral contraceptives. They are usually < 1cm in size, friable and reddish-pink. Usually asymptomatic, they can cause bleeding or become infected, leading to leucorrhoea (purulent vaginal discharge). They are usually benign but need to be differentiated from adenocarcinomas by histology.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 9
Correct
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During a street fight a boy sustained a laceration below the elbow. It was a deep cut that led to profuse bleeding from an artery situated on the supinator muscle immediately below the elbow. The vessel most likely to have been injured is?
Your Answer: Radial recurrent artery
Explanation:The radial recurrent artery is situated on the supinator muscle then passing between the brachialis and the brachioradialis muscles. It originates from the radial artery and ends by anastomosing with the terminal part of the Profunda brachii.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 10
Correct
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Streptokinase is used to break down clots in some cases of myocardial infarction, pulmonary embolism, and arterial thromboembolism; however, it is not recommended to use it again after 4 days from the first administration. Which complication could arise from repeated use?
Your Answer: Allergic reaction
Explanation:Streptokinase belongs to a group of medications known as ‘fibrinolytics’ and is an extracellular metallo-enzyme produced by beta-haemolytic streptococci, used as an effective clot-dissolving medication in patients with myocardial infarction and pulmonary embolism. As Streptokinase is a bacterial product, the body has the ability to build up an immunity to it. Therefore, it is recommended that this medication should not be used again after four days from the first administration, as it may not be as effective and may also cause an allergic reaction.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 11
Correct
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A 45 years old women was diagnosed with breast cancer. After a radical mastectomy to remove all axillary lymph nodes from her right breast, it was noticed that she had a winged scapula. Which nerve injury would explain this?
Your Answer: Long thoracic nerve
Explanation:The long thoracic nerve supplies the serratus anterior muscle. When this nerve is injured the muscle undergoes paralysis, which is seen clinically as winging of the scapula most apparent when the arm is lifted forward. The long thoracic nerve is greatly susceptible to injury during breast surgery because of its long and superficial course along the thorax from its origin, the brachial plexus, to the lower border of the serratus anterior muscle.
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This question is part of the following fields:
- Anatomy
- Breast
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Question 12
Correct
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An ultrasound report of a 35-year old female patient revealed that she had cancer of the pancreas and presented with subsequent severe obstructive jaundice. In which part of this was woman's pancreas was the tumour most likely located?
Your Answer: Head
Explanation:The pancreas is divided into five parts; the head, body, neck, tail, and the uncinate process. Of the five parts, tumours located at the head of the pancreas in most instances cause obstruction of the common bile duct more often than tumours in the other parts of the pancreas. This is because the common bile duct passes through the head of the pancreas from the gallbladder and the liver (it is formed where the cystic and the hepatic bile duct join) to empty bile into the duodenum. This biliary obstruction leads to accumulation of bile in the liver and a consequent bilirubinaemia (raised levels of blood bilirubin). This results in jaundice. The pancreas is not divided into lobes.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 13
Incorrect
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A new-born was found to have an undeveloped spiral septum in the heart. This is characteristic of which of the following?
Your Answer: Atrioventricular septal defect
Correct Answer: Persistent truncus arteriosus
Explanation:Persistent truncus arteriosus is a congenital heart disease that occurs when the primitive truncus does not divide into the pulmonary artery and aorta, resulting in a single arterial trunk. The spiral septum is created by fusion of a truncal septum and the aorticopulmonary spiral septum. Incomplete development of these septa results in incomplete separation of the common tube of the truncus arteriosus and the aorticopulmonary trunk.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 14
Correct
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A 22-year old man presented with a mass in his left scrotum which was more prominent when standing and felt like a 'bag of worms'. Examination revealed a non-tender mass along the spermatic cord. Also, the right testis was larger than the left testis. What is the likely diagnosis?
Your Answer: Varicocele
Explanation:Varicocele refers to dilatation and increased tortuosity of the pampiniform plexus – which is a network of veins found in spermatic cord that drain the testicle. Defective valves or extrinsic compression can result in outflow obstruction and cause dilatation near the testis. Normal diameter of the small vessels ranges from 0.5 – 1.5mm. A varicocele is a dilatation more than 2mm.
The plexus travels from the posterior aspect of testis into the inguinal canal with other structures forming the spermatic cord. They then form the testicular veins out of which the right testicular vein drains into the inferior vena cava and the left into the left renal vein.
It affects 15-20% men, and 40% of infertile males. Usually diagnosed in 15-25 years of age, they are rarely seen after 40 years of age. Because of the vertical path taken by the left testicular vein to drain into left renal vein, 98% idiopathic varicoceles occur on the left side. It is bilateral in 70% cases. Right-sided varicoceles are rare.
Symptoms include pain or heaviness in the testis, infertility, testicular atrophy, a palpable mass, which is non-tender and along the spermatic cord (resembling a ‘bag of worms’). The testis on the affected side might be smaller.
Diagnosis can be made by ultrasound. Provocative measures such as Valsalva manoeuvre or making the patient stand up to increase the dilatation by increasing the intra-abdominal venous pressure.
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This question is part of the following fields:
- Pathology
- Urology
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Question 15
Incorrect
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Internal haemorrhoids are painless and only sensitive to stretch. They are formed from folds of the mucous membrane and the submucosa of the anal canal which contain varicose branches of the:
Your Answer: Inferior rectal vein
Correct Answer: Superior rectal vein
Explanation:Internal haemorrhoids are formed by varicosities of the branches of the superior rectal vein.
External haemorrhoids are formed by varicosities of the branches of the inferior rectal vein.
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This question is part of the following fields:
- Anatomy
- Colorectal
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Question 16
Correct
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A 40-year old woman with portal hypertension has impaired venous drainage of the anal canal above the pectinate line. Thus, there might be an increase in blood flow downward to the systemic venous system via anastomoses with the inferior rectal vein. This is a tributary of?
Your Answer: Internal pudendal vein
Explanation:The inferior rectal vein drains into the internal pudendal vein. In addition the external iliac vein is one of the two branches of the common iliac vein however the internal iliac vein and it’s tributaries (including the pudendal vein) are much more important in draining the pelvic structures.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 17
Incorrect
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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.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 18
Incorrect
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Which of the following muscles aid in inspiration?
Your Answer: Diaphragm and abdominal muscles
Correct Answer: Diaphragm and external intercostals
Explanation:The diaphragm and external intercostals are muscles of inspiration as they increase the volume of thoracic cavity and reduce the intrathoracic pressure. Muscles of expiration include abdominal muscles and internal intercostals.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 19
Incorrect
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Two boys were playing when one of them brought the forearm of the other behind his back. This resulted in a stretching of the lateral rotator of the arm. Which of the following muscles was most likely to have been involved?
Your Answer: Subscapularis
Correct Answer: Infraspinatus
Explanation:There are two lateral rotators of the arm, the infraspinatus and the teres minor muscles. The infraspinatus muscle receives nerve supply from C5 and C6 via the suprascapular nerve, whilst the teres minor is supplied by C5 via the axillary nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 20
Correct
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The nasolacrimal duct is a membranous canal. It extends from the lower part of the lacrimal sac and drains into which structure?
Your Answer: Inferior meatus
Explanation:The nasolacrimal duct carries tears from the lacrimal sac of the eye into the nasal cavity. The duct begins in the eye socket between the maxillary and lacrimal bones, from where it passes downwards and backwards. The opening of the nasolacrimal duct into the inferior nasal meatus of the nasal cavity is partially covered by a mucosal fold (valve of Hasner or plica lacrimalis). Excess tears flow through the nasolacrimal duct which drains into the inferior nasal meatus.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 21
Incorrect
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A 30 year old gym coach presented to the surgical out patient clinic with a lump in the inguinal region. He was booked for surgery, during which, the surgeon opened the inguinal region and found a hernial sac with a small segment of intestine projecting through the abdominal wall. It was located just above the inguinal ligament and lateral to the inferior epigastric vessels. What type of hernia was this?
Your Answer: A direct inguinal hernia
Correct Answer: An indirect inguinal hernia
Explanation:An indirect inguinal hernia exits the abdominal cavity lateral to the inferior epigastric vessels and enters the inguinal canal through the deep inguinal ring. These are the most common types of hernias often caused by heavy weigh lifting. Direct inguinal hernias exit the abdominal cavity medial to the inferior epigastric vessels through weak fascia.
Congenital inguinal hernias are indirect hernias that occur due to persistence of the processus vaginalis.
Femoral hernias occur when abdominal viscera push through the femoral ring in the femoral canal.
Incisional hernia occurs after surgery when the omentum or organ protrudes through a previous site of incision.
Obturator hernia are a very rare type of hernia where the pelvic or abdominal contents protrude through the obturator foramen.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 22
Correct
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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: 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.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 23
Incorrect
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A 75-year old patient is in atrial fibrallation but has never been on anticoagulation therapy. To reduce the risk of future emboli, she would benefit from starting on long-term warfarin. Arterial emboli leading to acute limb ischaemia most commonly lodge at which one of the following sites?
Your Answer: Popliteal artery
Correct Answer: Common femoral artery
Explanation:The common femoral artery is the commonest site of arterial emboli causing acute limb ischemia. The treatment of choice is urgent femoral embolectomy.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 24
Incorrect
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Which of the following muscle divide the posterior triangle of the neck into the occipital and the subclavian triangle?
Your Answer: Superior belly of the omohyoid
Correct Answer: Inferior belly of the omohyoid
Explanation:The posterior triangle (or lateral cervical region) is a region of the neck bounded in front by the sternocleidomastoid; behind, by the anterior margin of the trapezius; inferiorly by the middle third of the clavicle and superiorly by the occipital bone. The posterior triangle is crossed, about 2.5 cm above the clavicle, by the inferior belly of the omohyoid muscle, which divides the space into two triangles: an upper or occipital triangle and a lower or subclavian triangle (or supraclavicular triangle).
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 25
Incorrect
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What is the pH of freshly formed saliva at ultimate stimulation?
Your Answer: 4.4
Correct Answer: 8
Explanation:Saliva has four major components: mucus (lubricant), α-amylase (enzyme that initiates digestion of starch), lingual lipase (enzyme that begins fat digestion), and a slightly alkaline electrolyte solution for moistening food. As the secretion rate of saliva increases, its osmolality increases. Moreover, the pH changes from slightly acidic (at rest) to basic (pH 8) at ultimate stimulation. This occurs due to increase of HCO3-. Amylase and mucus also increase in concentration after stimulation.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 26
Incorrect
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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: Femoral branch of the genitofemoral
Correct 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.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 27
Correct
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A 16 year old girl fractured a bone in her left foot. Upon examination the clinician discovered that the fracture affected the insertion of the peroneus brevis muscle. Which of the following bones was most likely affected?
Your Answer: Base of the fifth metatarsal
Explanation:The peroneus brevis muscle originates from the lower two-thirds of the lateral body of the fibula and has inserts at the base of the fifth metatarsal. Fractures to this bone are common and can be due to infection, trauma, overuse and repetitive use.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 28
Incorrect
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What is the most likely cause of prolonged bleeding time in a 40 year old women admitted for a laparoscopic cholecystectomy?
Your Answer: Protein S deficiency
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.
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This question is part of the following fields:
- General
- Physiology
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Question 29
Incorrect
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Question 30
Correct
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A 76-year-old woman is diagnosed with diabetes mellitus after a urine test revealed she has glucosuria. Glucosuria may occur due to inadequate glucose reabsorption at:
Your Answer: Proximal convoluted tubule
Explanation:Glucose is reabsorbed almost 100% via sodium–glucose transport proteins (apical) and GLUT (basolateral) in the proximal convoluted tubule. Glycosuria or glucosuria is a condition of osmotic diuresis typical in those suffering from diabetes mellitus. Due to a lack of insulin, plasma glucose levels are above normal. This leads to saturation of receptors in the kidneys and glycosuria usually at plasma glucose levels above 11 mmol/l. Rarely, glycosuria is due to an intrinsic problem with glucose reabsorption within the kidneys (such as Fanconi syndrome), producing a condition termed renal glycosuria.
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This question is part of the following fields:
- Physiology
- Renal
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SESSION STATS - PERFORMANCE PER SPECIALTY
