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Question 1
Correct
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A 34-year-old man is receiving chemotherapy for non-Hodgkin's lymphoma. Which of the following chemotherapy regimens would be used in this case?
Your Answer: CHOP
Explanation:CHOP is the acronym for a chemotherapy regimen used in the treatment of non-Hodgkin’s lymphoma, comprising cyclophosphamide, hydroxyrubicin (adriamycin), vincristine and prednisone. This regimen can also be combined with the monoclonal antibody rituximab if the lymphoma is of B cell origin; this combination is called R-CHOP.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 2
Correct
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Point of entry of the vagal trunk into the abdomen:
Your Answer: Oesophageal hiatus
Explanation:The oesophageal hiatus is located in the muscular part of the diaphragm a T10 and is above, in front and a little to the left of the aortic hiatus. It transmits the oesophagus, the vagus nerves and some small oesophageal arteries.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 3
Correct
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Blood supply to the posterior compartment of the thigh is supplied by which artery?
Your Answer: Perforating
Explanation:There are usually 3 perforating arteries:
The first gives branches to the adductor brevis and magnus, biceps femoris and gluteus maximus and anastomoses with the inferior gluteal, medial and lateral femoral circumflex.
The second artery supplies the posterior femoral muscles and anastomose with the first and third perforating vessels.
The third supplies the posterior femoral muscles.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 4
Correct
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A Monospot test in a 17-year old boy presenting with fever, multiple palpable lymph nodes and mild icterus was positive. His blood investigation is likely to show which of the following?
Your Answer: Atypical lymphocytosis
Explanation:Epstein-Barr virus is the causative agent for infectious mononucleosis leading to presence of atypical lymphocytes in blood. Usually symptomatic in older children and adults, the incubation period is 30-50 days. Symptoms include fatigue, followed by fever, adenopathy and pharyngitis. Fatigue can last for months and is maximum in first few weeks. Fever spikes in the afternoon or early evening, with temperature around 39.5 – 40.5 °C. The ‘typhoidal’ form where fatigue and fever predominate has a low onset and resolution. Pharyngitis resemble that due to streptococcus and can be severe and painful. Lymphadenopathy is bilaterally symmetrical and can involve any nodes, specially the cervical ones. Mild splenomegaly is seen in 50% cases, usually in 2-3rd week. Mild tender hepatomegaly can occur. Less common manifestations include maculopapular eruptions, jaundice, periorbital oedema and palatal enanthema. Diagnostic tests include full blood count and a heterophil antibody test. Morphologically abnormal lymphocytes account for 80% cells and are heterogenous, unlike leukaemia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 5
Correct
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A 60-year-old woman has had persistent diarrhoea for a week. A stool test reveals an infection by Clostridium difficile. Which of the following antibiotics could be used to treat the infection?
Your Answer: Oral vancomycin
Explanation:Three antibiotics are effective against Clostridium difficile:
Metronidazole 500 mg orally three times daily is the drug of choice, because of superior tolerability, lower price and comparable efficacy.
Oral vancomycin 125 mg four times daily is second-line therapy in particular cases of relapse or where the infection is unresponsive to metronidazole treatment.
Thirdly, the use of linezolid might also be considered.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 6
Correct
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A computer tomography guided needle biopsy is done on a patient with a cystic swelling in the left chest. The radiologist inserted the biopsy needle into the 9th intercostal space along the mid axillary line to aspirate the swelling and obtain tissue for histological diagnosis. In which space is the swelling most likely to be?
Your Answer: Costodiaphragmatic recess
Explanation:The costodiaphragmatic recess is the lowest point of the pleural sac where the costal pleura becomes the diaphragmatic pleura. At the midclavicular line, this is found between ribs 6 and 8; at the paravertebral lines, between ribs 10 and 12 and between ribs 8 and 10 at the midaxillary line.
The cardiac notch: is an indentation of the heart on the left lung, located on the anterior surface of the lung.
Cupola: part of the parietal pleura that extends above the first rib.
Oblique pericardial sinus: part of the pericardial sac located posterior to the heart behind the left atrium.
Costomediastinal recess: a reflection of the pleura from the costal surface to the mediastinal surface, is on the anterior surface of the chest.
The inferior mediastinum: is the space in the chest occupied by the heart.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 7
Correct
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Which of the deep fasciae located in the anterolateral abdominal wall form the inguinal ligament?
Your Answer: External abdominal oblique aponeurosis
Explanation:The inguinal ligament is the inferior border of the aponeurosis of the external oblique abdominis and extends from the anterior superior iliac spine to the pubic tubercle from whence it is reflected backward and laterally to attach to the pectineal line and form the lacunar ligament.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 8
Correct
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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.
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This question is part of the following fields:
- Physiology
- Renal
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Question 9
Incorrect
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A 35 year old male patient sustained a traumatic head injury. The patient had loss of consciousness, woke up momentarily when he was in the emergency room but became drowsy and comatose a few hours after. CT scan of the brain showed accumulation of blood between the dura and the cranial bone on the left side of his head. What type of haemorrhage did the patient have?
Your Answer: Subdural
Correct Answer: Epidural
Explanation:Epidural hematoma, also known as epidural bleeding, is a type of traumatic brain injury (TBI) in which a build-up of blood occurs between the dura mater (the tough outer membrane of the central nervous system) and the skull. The spinal cord is also covered by a layer of dura mater, so epidural bleeds may also occur in the spinal column. Often due to trauma, the condition is potentially deadly because the build-up of blood may increase pressure in the intracranial space, compressing delicate brain tissue, and causing brain shift. The condition is present in one to three percent of head injuries. Around 15–20% of epidural hematomas are fatal.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 10
Incorrect
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Which of the following malignancies is associated with the development of Lambert-Eaton myasthenic syndrome?
Your Answer: Malignant melanoma
Correct Answer: Lung cancer
Explanation:Lambert–Eaton myasthenic syndrome is a rare disorder of the neuromuscular junction. It can occur as a solitary diagnosis but it can also occur as a paraneoplastic syndrome associated with lung cancer, particularly small-cell histology. It can also be associated with other cancers such as lymphoma, non-Hodgkin’s lymphoma, T-cell leukaemia, non-small-cell lung cancer, prostate cancer and thymoma.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 11
Incorrect
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During a procedure in the mediastinum, the surgeon accidentally injured a key structure that lies immediately anterior to the thoracic duct. Which structure is likely to be injured?
Your Answer: Azygos vein
Correct Answer: Oesophagus
Explanation:In the mid-thorax, the azygos vein, thoracic duct and aorta (in this order from right to the left) are all located posterior to the oesophagus. The superior vena cava, left internal jugular vein and trachea are not found in the mid thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 12
Incorrect
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Which of the following substances will enhance the activity of antithrombin III?
Your Answer: Citrate
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.
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This question is part of the following fields:
- General
- Physiology
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Question 13
Incorrect
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Which of these conditions is mithramycin used for?
Your Answer: Organ transplantation
Correct Answer: Hypercalcaemia of malignancy
Explanation:Mithramycin or Plicamycin is a tricyclic pentaglycosidic antibiotic derived from Streptomyces strains. It inhibits RNA and protein synthesis by adhering to DNA. It is used as a fluorescent dye and as an antineoplastic agent. It is also used to reduce hypercalcaemia, especially caused by malignancy. Plicamycin is currently used in multiple areas of research, including cancer cell apoptosis and as a metastasis inhibitor.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 14
Correct
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A 30-year-old woman feels thirsty. This thirst is probably due to:
Your Answer: Increased level of angiotensin II
Explanation:Thirst is the basic need or instinct to drink. It arises from a lack of fluids and/or an increase in the concentration of certain osmolites such as salt. If the water volume of the body falls below a certain threshold or the osmolite concentration becomes too high, the brain signals thirst. Excessive thirst, known as polydipsia, along with excessive urination, known as polyuria, may be an indication of diabetes. Angiotensin II is a hormone that is a powerful dipsogen (i.e. it stimulates thirst) that acts via the subfornical organ. It increases secretion of ADH in the posterior pituitary and secretion of ACTH in the anterior pituitary.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 15
Incorrect
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Which of the following muscles attaches to the pterygomandibular raphe?
Your Answer: Lateral pterygoid muscle
Correct 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.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 16
Incorrect
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T lymphocytes that express the MCH type II antigen are most likely to produce which of the following cytokines?
Your Answer: Interleukin-1
Correct Answer: Gamma interferon
Explanation:Interferon gamma is a soluble cytokine previously known as the macrophage activating factor. It is the only member belonging to the type II class of the interferons. It is secreted by a number of cells taking part in the immune reaction including: T-helper cells (CD-4), cells with immunological memory (CD45PA), killer cells (CD8), dendrite cells (CD23,35), natural killer cells (CD16) and B lymphocytes (CD22,CD23). It has both a defending as well as a pathological effect. It induces differentiation in the myeloid cell in the bone marrow. If macrophages are infected by parasites it activates the macrophages to destroy them. IFN-γ strengthens the anti-tumour activities of the cytotoxic lymphocytes. Together with CD4 or CD8 toxins, produced by lymphocytes, it suppresses the growth of the tumour cells. along with these functions it increases the non specific response of the natural killer cells, causing changes in the cell membrane surface to prevent adhesion and penetration of a virus. It can either increase or decrease B cell response and it activates osteoclasts which increases bone resorption.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 17
Incorrect
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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: Tail of the pancreas
Correct 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.
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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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The circle of Willis is one of the cerebrovascular safeguards comprised of the left and the right posterior communicating artery. Which of the following arteries in the brain is connected to the posterior cerebral artery by these posterior communicating arteries?
Your Answer: Anterior communicating artery
Correct Answer: Internal carotid artery
Explanation:The Circle of Willis is an anastomosis of cerebral arteries that are located at the base of the brain. The Circle of Willis is one of the important safeguards that ensure back up of blood supply to parts of the brain in case of any cerebrovascular accident. The Circle of Willis is made up of an anterior portion of arteries including; the anterior cerebral arteries. The anterior cerebral arteries are connected to the posterior portion of the circle of Willis by the anterior communicating artery. The posterior portion is made up of the posterior cerebral artery which branch off from the basilar artery. The posterior cerebral artery are connected to the anterior portion of the circle of Willis by the posterior communicating artery. The posterior communicating artery connects the posterior cerebral artery to the internal carotid artery. The circle of Willis receives blood supply from the left and right internal carotid arteries that continues as the middle cerebral artery and posteriorly from the two vertebral arteries that join to form the basilar artery.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 19
Correct
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A 68-year-old woman complains of headaches, dizziness, and memory loss. About a month ago, she fell from a staircase but only suffered mild head trauma. What is the most likely diagnosis in this case?
Your Answer: Chronic subdural haematoma
Explanation:A quarter to a half of patients with chronic subdural haematoma have no identifiable history of head trauma. If a patient does have a history of head trauma, it usually is mild. The average time between head trauma and chronic subdural haematoma diagnosis is 4–5 weeks. Symptoms include decreased level of consciousness, balance problems, cognitive dysfunction and memory loss, motor deficit (e.g. hemiparesis), headache or aphasia. Some patients present acutely. They usually result from tears in bridging veins which cross the subdural space, and may cause an increase in intracranial pressure (ICP).
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This question is part of the following fields:
- Neurology
- Pathology
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Question 20
Incorrect
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The proximal tubule is the portion of the ductal system of the nephron of the kidney which leads from Bowman's capsule to the loop of Henle. Which of the following is most likely to be seen in a sample of fluid leaving the proximal tubule?
Your Answer: It will have more K+ than plasma
Correct Answer: It will have no amino acids
Explanation:The proximal tubule is the portion of the duct system of the nephron leading from Bowman’s capsule to the loop of Henlé. The most distinctive characteristic of the proximal tubule is its brush border (or ‘striated border’). The luminal surface of the epithelial cells of this segment of the nephron is covered with densely packed microvilli forming a border which greatly increases the luminal surface area of the cells, presumably facilitating their reabsorptive function. Glucose, amino acids, inorganic phosphate, and some other solutes are100% reabsorbed via secondary active transport through co-transporters driven by the sodium gradient out of the nephron.
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This question is part of the following fields:
- Physiology
- Renal
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Question 21
Incorrect
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A biopsy is performed on a 67-year-old-man with testicular seminoma; it reveals that the tumour affects the tunica vaginalis. The tumour stage in this case is:
Your Answer: T1
Correct Answer: T2
Explanation:The primary tumour staging for testicular seminoma is as follows, according to AJCC guidelines:
Tis: intratubular germ cell neoplasia (carcinoma in situ)
T1: tumour limited to testis/epididymis without vascular or lymphatic invasion; the tumour can invade into the tunica albuginea but not the tunica vaginalis
T2: tumour limited to testis/epididymis with vascular or lymphatic invasion or tumour extending through the tunica albuginea with involvement of the tunica vaginalis
T3: tumour invading the spermatic cord, with or without vascular/lymphatic invasion
T4: tumour invading the scrotum, with or without vascular/lymphatic invasion.
According to these guidelines, the tumour in this case has a T2 stage.
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This question is part of the following fields:
- Pathology
- Urology
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Question 22
Correct
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Which tumour site is more commonly involved in adults than in children?
Your Answer: Lung
Explanation:In adults, the most common primary site of tumour is in the lungs, compared to children wherein the most common primary site is the blood.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 23
Correct
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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: 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.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 24
Incorrect
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What is the linea aspera:
Your Answer: Is a landmark on the tibia
Correct Answer: Serves as an attachment for adductors of the thigh
Explanation:The linea aspera is a prominent longitudinal ridge or crest on the middle third of the femur. It has a medial and a lateral lip and a narrow, rough, intermediate line. The vastus medialis arises from the medial lip of the linea aspera and has superior and inferior prolongations. The vastus lateralis takes origin from the lateral lip . The adductor magnus is inserted into the linea aspera. Two muscles are attached between the vastus lateralis and the adductor magnus: the gluteus maximus is inserted above and the short head of the biceps femoris arises below. Four muscles are inserted between the adductor magnus and the vastus medialis: the iliacus and pectineus superiorly, and the adductor brevis and adductor longus inferiorly.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 25
Correct
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A tumour on the floor of the fourth ventricle is most likely to compress which of the following cranial nerve nuclei?
Your Answer: Abducent
Explanation:The fourth ventricle, is a cavity of the brains ventricular system in which the cerebrospinal fluid is formed. This cavity is located behind the pons and upper half of the medulla oblongata. It extends from the cerebral aqueduct, to its connection to the third ventricle, and to the obex- which is the caudal tip of the fourth ventricle. The floor of the fourth ventricle consists of three parts – superior, intermediate and inferior. This inferior aspect of the floor of the fourth ventricle has the nucleus of the abducens nerve, CN VI which is looped over by the facial nerve.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 26
Incorrect
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A histological examination of a lump showed an abnormal amount and arrangement of normal tissue in an otherwise normal area. This condition is known as?
Your Answer: Embryonal tumour
Correct Answer: Hamartoma
Explanation:A hamartoma is a condition best described as tissue normally present in an area arranged haphazardly in an disorganized, abnormal fashion. They are never malignant and do not metastasis.
All the neoplastic, cancerous lesions comprise of a mixture of different cells that are not normal to that area.
Metaplasia is a change in the type of the epithelium.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 27
Correct
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A surgeon ligates the left middle suprarenal artery while carrying out a left adrenalectomy. Where does the left middle suprarenal artery originate?
Your Answer: Abdominal aorta
Explanation:Middle suprarenal arteries arise from either side of the abdominal aorta, opposite the superior mesenteric artery.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 28
Correct
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If a catheter is placed in the main pulmonary artery of a healthy 30-year-old woman, which of the following will be its mean pulmonary arterial pressure?
Your Answer: 15 mmHg
Explanation:The pulmonary artery pressure (PA pressure) is a measure of the blood pressure found in the main pulmonary artery. The hydrostatic pressure of the pulmonary circulation refers to the actual pressure inside pulmonary vessels relative to atmospheric pressure. Hydrostatic (blood pressure) in the pulmonary vascular bed is low compared with that of similar systemic vessels. The mean pulmonary arterial pressure is about 15 mmHg (ranging from about 13 to 19 mmHg) and is much lower than the average systemic arterial pressure of 90 mmHg.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 29
Correct
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A 34-year-old woman with severe burns, presented to casualty with a blood pressure of 75/40 mmHg and pulse of 172/minute. Obviously the patient is in shock. Which type of shock is it more likely to be?
Your Answer: Hypovolaemic shock
Explanation:Shock is a life-threatening condition that occurs when the organs and tissues of the body are not receiving a sufficient flow of blood. Lack of blood flow, oxygen and nutrients results in the inability to function properly and damage to many organs. Shock requires immediate treatment because, if left untreated the impaired tissue perfusion and cellular hypoxia can cause irreversible tissue injury, collapse, coma or even death. There are various types of physiological shock, including: cardiogenic (due to heart damage), hypovolaemic (due to low total volume of blood or plasma), neurogenic (due to nervous system damage), septic (due to infections) and anaphylactic shock (due to allergic reactions). Hypovolaemic shock can be caused by blood loss due to trauma, internal bleeding or other fluid loss due to severe burns, prolonged diarrhoea, vomiting and sweating.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 30
Incorrect
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A patient is brought to the accident and emergency department. He is said to have been involved in a mall explosion. Chest imaging reveals metal fragments in his thoracic cavity. He also has a pericardial effusion suggestive of a pericardial tear. An emergency thoracotomy is done which revealed a tear of the pericardium inferiorly. The surgeon began to explore for fragments in the pericardial sac with his hand from below the apex. He slips his fingers upward and to the right within the sac until they were stopped by the cul-de-sac formed by the pericardial reflection near the base of the heart. His finger tips were now in the:
Your Answer: Coronary sulcus
Correct Answer: Oblique pericardial sinus
Explanation:Transverse sinus: part of pericardial cavity that is behind the aorta and pulmonary trunk and in front of the superior vena cava separating the outflow vessels from the inflow vessels.
Oblique pericardial sinus: is behind the left atrium where the visceral pericardium reflects onto the pulmonary veins and the inferior vena cava. Sliding a finger under the heart will take you to this sinus.
Coronary sinus: large vein that drains the heart into the right atrium. Located on the surface of the heart.
Coronary sulcus: groove on the heart demarcating the atria from the ventricles.
Costomediastinal recess: part of the pleural sac where the costal pleura transitions to become the mediastinal pleura.
Sulcus terminalis: a groove between the right atrium and the vena cava.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 31
Correct
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Choose the most correct answer regarding the common peroneal nerve.
Your Answer: It gives rise to the nerve that supplies the anterior compartment leg muscles
Explanation:The common peroneal nerve divides beneath the peroneus longus muscle and gives off articular and lateral sural cutaneous nerves which supply muscular branches to the muscles of the anterior compartment of the leg which are the tibialis anterior, extensor digitorum, peroneus tertius and extensor hallucis longus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 32
Correct
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Chronic obstructive pulmonary disease (COPD) is likely to result in:
Your Answer: Respiratory acidosis
Explanation:COPD leads to respiratory acidosis (chronic). This occurs due to hypoventilation which involves multiple causes, such as poor responsiveness to hypoxia and hypercapnia, increased ventilation/perfusion mismatch leading to increased dead space ventilation and decreased diaphragm function.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 33
Correct
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Which of the following can lead to haemolytic anaemia?
Your Answer: Presence of haemoglobin S
Explanation:Haemoglobin S is an abnormal type of haemoglobin seen in sickle cell anaemia. This allows for the haemoglobin to crystalize within the RBC upon exposure to low partial pressures of oxygen. This results in rupture of the RBCs as they pass through microcirculation, especially in the spleen. This can cause blockage of the vessel down stream and ischaemic death of tissues, accompanied by severe pain.
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This question is part of the following fields:
- General
- Physiology
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Question 34
Correct
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After a prolonged coronary artery bypass surgery, a 60-year old gentleman was transfused 3 units of fresh-frozen plasma and 2 units of packed red cells. Two days later, the nurse noticed that he was tachypnoeic and chest X-ray showed signs consistent with adult respiratory distress syndrome. Which of the following variables will be low in this patient?
Your Answer: Compliance of the lung
Explanation:Acute or adult respiratory distress syndrome (ARDS) is a reaction to several forms of lung injuries and is commonly associated with sepsis and SIRS (systemic inflammatory response syndrome), severe traumatic injury, severe head injury, narcotics overdose, drowning, pulmonary contusion, and multiple blood transfusions. There is an increase in risk due to pre-existing liver disease or coagulation abnormalities. It results due to indirect toxic effects of neutrophil-derived inflammatory mediators in the lungs. ARDS is defined by the 1994 American–European Consensus Committee as the acute onset of bilateral infiltrates on chest X-ray, a partial pressure of arterial oxygen (pa(O2)) to fraction of inspired oxygen Fi(O2) ratio of less than 200 mmHg and a pulmonary artery occlusion pressure of less than 18 or the absence of clinical evidence of left arterial hypertension. ARDS is basically pulmonary oedema in the absence of volume overload or poor left ventricular function. This is different from acute lung injury, which shows a pa(O2)/Fi(O2) ratio of less than 300 mmHg. Pathogenesis of ARDS starts from damage to alveolar epithelium and vascular endothelium, causing increased permeability. Damage to surfactant-producing type II cells disrupts the production and function of pulmonary surfactant, causing micro atelectasis and poor gas exchange. There is a decrease in lung compliance and increase in work of breathing. Eventually, there is resorption of alveolar oedema, regeneration of epithelial cells, proliferation and differentiation of type II alveolar cells and alveolar remodelling. Some show resolution and some progress to fibrosing alveolitis, which involves the deposition of collagen in alveolar, vascular and interstitial spaces.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 35
Incorrect
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A surgeon performing a thymectomy to remove a malignant thymoma is careful to avoid damaging an important nerve lying around the arch of the aorta. Which nerve is the surgeon trying to preserve?
Your Answer: Right sympathetic trunk
Correct Answer: Left Vagus
Explanation:The left vagus nerve lies on the lateral surface of the aortic arch. The left recurrent laryngeal nerve arises from the vagus and loops around the arch of the aorta. This nerve is at risk of injury during surgery.
The right and left phrenic nerves, being lateral to the vagus, do not loop around the arch of the aorta.
The sympathetic trunks, both right and left, are located in the posterior chest; not near the aortic arch.
The right vagus: not involved with the aortic arch.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 36
Correct
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An 18 year-old with an iron deficient diet was prescribed an iron supplement by her GP. Lack of iron often results in:
Your Answer: Hypochromic anaemia
Explanation:Iron deficiency anaemia is the most common type of anaemia. It can occur due to deficiency of iron from decreased intake, increased loss or inadequate absorption. An MCV less than 80 will indicated iron deficiency anaemia. On the smear the RBCs will be microcytic hypochromic and will also show poikilocytosis. Iron profile tests are important to make a diagnosis. Clinically the patient will be pale and lethargic.
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This question is part of the following fields:
- General
- Physiology
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Question 37
Correct
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Staphylococcus aureus can be identified in the laboratory based on the clotting of plasma. Which microbial product is responsible for this activity?
Your Answer: Coagulase
Explanation:Staphylococcus aureus is the most pathogenic species and is implicated in a variety of infections. S. aureus can be identified due to its production of coagulase. The staphylococcal enzyme coagulase will cause inoculated citrated rabbit plasma to gel or coagulate. The coagulase converts soluble fibrinogen in the plasma into insoluble fibrin.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 38
Correct
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Which of the following changes in the histology of the cell is most likely to be accompanied by disruption of the cell membrane following an injury?
Your Answer: Coagulative necrosis
Explanation:The process of necrosis ends with the rupture of the cell membrane and the consequent release of the cellular components into the surrounding tissue. Apoptosis, pyknosis and karyorrhexis are not reversible events but the cell membrane remains intact. Cloudy swelling and hydropic changes are also reversible but again the cell membrane remains intact and they are therefore different and distinct from necrosis.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 39
Incorrect
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What is the role of ICAM-1 and VCAM-1 in the inflammatory process?
Your Answer: Chemotaxis
Correct Answer: Leukocyte adhesion
Explanation:Steps involved in leukocyte arrival and function include:
1. margination: cells migrate from the centre to the periphery of the vessel.
2. rolling: selectins are upregulated on the vessel walls.
3. adhesion: upregulation of the adhesion molecules ICAM and VCAM on the endothelium interact with integrins on the leukocytes. Interaction of these results in adhesion.
4. diapedesis and chemotaxis: diapedesis is the transmigration of the leukocyte across the endothelium of the capillary and towards a chemotactic product.
5. phagocytosis: engulfing the offending substance/cell.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 40
Correct
-
A 78-year-old woman was brought to the emergency department with decreased consciousness, weakness and dehydration. Which serum electrolyte would most likely be low in this patient?
Your Answer: Na+
Explanation:Hyponatremia is a sodium level below 135 mEq/L. Signs and symptoms may include: nausea with vomiting, fatigue, headache or confusion, cramps or spasm, irritability and restlessness and severe cases may lead to seizures and comma.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 41
Incorrect
-
A 20-year old college student was diagnosed with meningitis that had developed due to an acute cavernous sinus thrombosis from an ear infection. Which of the following superficial venous routes is the usual path that an infected blood clot takes to reach the cavernous sinus?
Your Answer: Lingual vein
Correct Answer: Facial vein
Explanation:The facial vein is the usual communication between the cavernous sinus and the pterygoid sinus. It is through this vein that an infected clot can travel to the cavernous sinus and cause infection. The pterygoid plexus is a venous plexus that is situated between the temporalis muscle and lateral pterygoid muscle, and partly between the two pterygoid muscles. The pterygoid plexus is connected to the facial vein by the deep facial vein. This connection is what makes this area where this sinus and the facial vein are located a danger zone. The danger zone or triangle of the face is the area from the corners of the mouth to the nose bridge. The sinus connection in this area makes it possible for infection to reach the cavernous sinus and at times cause meningitis.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 42
Correct
-
Which of the following statements regarding the arteries in the neck are TRUE?
Your Answer: The thyrocervical trunk typically gives rise to the inferior thyroid artery, transverse cervical artery and suprascapular artery
Explanation:The thyrocervical trunk is one of the three branches of the first part of the subclavian artery and gives numerous branches which supply viscera of the neck, the brachial plexus, neck muscles and scapular anastomoses. The vertebral arteries are major arteries of the neck. They arise as branches from the subclavian arteries and merge to form the single midline basilar artery. The carotid sinus is a dilated area at the base of the internal carotid artery just superior to the bifurcation of the internal carotid and external carotid at the level of the superior border of thyroid cartilage.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 43
Correct
-
A 60-year old patient having a history of cholelithiasis that led to recurrent pain, bloating, nausea and vomiting, was scheduled for surgery to have the gallbladder removed. During the cholecystectomy, the registrar conducting the procedure accidentally punctured a blood vessel that lies immediately posterior to the omental foramen and blood filled the operating field. Which of the following blood vessels was likely punctured?
Your Answer: Inferior vena cava
Explanation:The omental foramen is the pathway that connects the greater peritoneal sac and the lesser peritoneal sac. The omental foramen is bordered posteriorly by the inferior vena cava. This is the blood vessel that would most likely be punctured.
The aorta and its branch, the renal artery, lie postero-lateral to the omental foramen and are deeper than the inferior vena cava hence making them less likely to be injured.
The hepatic portal vein, the hepatic artery and the superior mesenteric vein borders the omental foramen anteriorly and would not be injured by a jab on the posterior border of the omental foramen.
Finally, the splenic artery is found in the splenorenal ligament that borders the omental foramen laterally to the left.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 44
Correct
-
Which of the following structures is derived from the dorsal mesogastrium of the stomach during the development of the gut?
Your Answer: Greater omentum
Explanation:In a developing foetus, the stomach has two mesogastria from which most of the abdominal ligaments develop. These two mesogastria are the; ventral mesogastrium and the dorsal mesogastrium. During the embryological development of the gut, different organs develop in each mesogastrium; the spleen and pancreas in the dorsal mesogastrium while the liver in the ventral mesogastrium (with their associated ligaments). In the dorsal mesogastrium the following structures develop; the greater omentum (containing the gastrophrenic ligament and the gastrocolic ligament), gastrosplenic ligament, mesentery, splenorenal ligament and phrenicocolic ligament. The structures that develop from the ventral mesogastrium include the; lesser omentum (containing the hepatoduodenal ligament and the hepatogastric ligament) in association with the liver; the coronary ligament (left triangular ligament, right triangular ligament and hepatorenal ligament) and the falciform ligament (round ligament of liver and ligamentum venosum within).
There are also folds that develop from the dorsal mesogastrium which include; umbilical folds, supravesical fossa, medial inguinal fossa, lateral umbilical fold, lateral inguinal fossa and Ileocecal fold.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 45
Correct
-
For calculation of cardiac output by Fick's principle, which of the following vessels is the best source of venous blood to determine the arterial-to-venous oxygen tension difference?
Your Answer: Pulmonary artery
Explanation:Fick’s principle states that the total uptake (or release) of a substance by peripheral tissues is equal to the product of the blood flow to the peripheral tissues and the arterial– venous concentration difference (gradient) of the substance. It is used to measure the cardiac output, and the formula is Cardiac output = oxygen consumption divided by arteriovenous oxygen difference. Assuming there are no shunts across the pulmonary system, the pulmonary blood flow equals the systemic blood flow. The arterial and venous blood oxygen content is measured by sampling from the pulmonary artery (low oxygen content) and pulmonary vein (high oxygen content). Peripheral arterial blood is used as a surrogate for the pulmonary vein.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 46
Correct
-
A 46-year old lady presents with chief complaints of a large mass in the left breast. Histopathology of the mass revealed a stromal component with an epithelial component. What is the likely lesion?
Your Answer: Phyllodes tumour
Explanation:Phyllodes tumours are large, quickly growing tumours which arise from the periductal stroma of the breast. These are fibroepithelial tumours and account for less than 1% of breast cancers. These tumours can be benign, borderline or malignant based on the histology. The tumour usually affects adult women, mostly between the age of 40 to 50 years. It can be confused with fibroadenoma, which however affects much younger patients.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 47
Correct
-
A 28-year old lady comes to the surgical clinic with a recently detected lump in her right breast. On examination, the lump is found to be 1cm, rubbery, mobile with no palpable axillary nodes. Mammography reveals no microcalcifications and the opposite breast appears normal. What is the likely diagnosis?
Your Answer: Fibroadenoma
Explanation:A benign breast tumour, fibroadenoma is common below the age of 30 years and occurs due to oestrogenic excess. It is characterised by proliferation of both glandular and stromal elements. Fibroadenomas are usually solitary and are mobile, not fixed to surrounding structures. The tumour is elastic, nodular and encapsulated with a grey-white cut surface. The two main histological types include intracanalicular and pericanalicular types, with both types often present in the same tumour. In the intracanalicular type, the stromal proliferation component predominates causing compression of ducts making them appear slit-like. In pericanalicular type, the fibrous stroma dominates around the ductal spaces so that they remain oval on cross section.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 48
Incorrect
-
Diffusion is the movement of molecules from a region of high concentration to a region of low concentration. Which of these changes will decrease the rate of diffusion of a substance?
Your Answer: An increase in membrane permeability
Correct Answer: An increase in the molecular weight of the substance
Explanation:Unless given IV, a drug must cross several semipermeable cell membranes before it reaches the systemic circulation. Drugs may cross cell membranes by diffusion, amongst other mechanisms. The rate of diffusion of a substance is proportional to the difference in the concentration of the diffusing substance between the two sides of the membrane, the temperature of the solution, the permeability of the membrane and, in the case of ions, the electrical potential difference between the two sides of the membrane.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 49
Incorrect
-
The dilator pupillae muscle is innervated by postganglionic sympathetic fibres. Where do the postganglionic sympathetic fibres originate?
Your Answer: Trigeminal ganglion
Correct Answer: Superior cervical ganglion
Explanation:The postganglionic sympathetic axons are derived from the superior cervical ganglion and innervate the eye and lacrimal gland allowing for vasoconstriction of the iris and sclera, pupillary dilation, widening of the palpebral fissure, and a reduction in tear production.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 50
Incorrect
-
Which of the following can occur even in the absence of brainstem co-ordination?
Your Answer: Vomiting
Correct Answer: Gastric emptying
Explanation:Although gastric emptying is under both neural and hormonal control, it does not require brainstem co-ordination. Increased motility of the orad stomach (decreased distensibility) or of the distal stomach (increased peristalsis), decreased pyloric tone, decreased duodenal motility or a combination of these, all increase the rate of gastric emptying. The major control mechanism for gastric emptying is through duodenal gastric feedback. The duodenum has receptors for the presence of acid, carbohydrate, fat and protein digestion products, osmolarity different from that of plasma, and distension. Activating these receptors decreases the rate of gastric emptying. Neural mechanisms involve both enteric and vagal pathways and a vagotomy impairs the gastric emptying regulation. CCK (cholecystokinin) slows gastric emptying at physiological levels of the hormone. Gastrin, secretin and glucose-1-phosphate also slow gastric emptying, but require higher doses.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 51
Incorrect
-
A 40 year old patient with an history of obesity has been diagnosed with meralgia parasthetica. The condition was discovered to be caused by the pinching of the lateral femoral cutaneous nerve. Injuries at what spinal levels usually affect this nerve?
Your Answer: L5, S1
Correct Answer: L2, L3
Explanation:The lateral femoral cutaneous nerve of the thigh arises from the dorsal division of the lumbar plexus of the second and the third lumbar nerves (L2 – L3). Spinal injuries at this level are likely to affect the lateral femoral cutaneous nerve. The lateral femoral cutaneous nerve innervates the skin on the lateral aspect of the thigh.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 52
Correct
-
Where is factor VIII predominantly synthesised?
Your Answer: Vascular endothelium
Explanation:Factor VIII is an important part of the coagulation cascade. Deficiency causes haemophilia A. It is synthesised predominantly by the vascular endothelium and is not affected by liver disease. In the circulation it is bound to von Willebrand factor and it forms a stable complex with it. It is activated by thrombin or factor Xa and acts as a co factor to factor IXa to activate factor X which is a co factor to factor Va. Thrombin cleaves fibrinogen in fibrin and forms a meshwork to trap RBC and platelets to form a clot.
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This question is part of the following fields:
- General
- Physiology
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Question 53
Incorrect
-
The extent of cancer growth can be described through staging. What is taken into consideration when staging a cancer?
Your Answer: Cell differentiation
Correct Answer: Local invasion
Explanation:Cancer stage is based on four characteristics: the size of cancer, whether the cancer is invasive or non-invasive, whether the cancer has spread to the lymph nodes, and whether the cancer has spread to other parts of the body, in this case beyond the breast. Staging is important as it is often a good predictor of outcomes and treatment is adjusted accordingly.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 54
Correct
-
A patient with chronic renal disease, missed a day of his dialysis schedule., His serum potassium was 7.6 mmol/L when his electrolytes were checked. What is the ECG finding expected in this patient?
Your Answer: Tented T waves
Explanation:ECG characteristics of hyperkalaemia may show the following changes: P-waves are widened and of low amplitude due to slowing of conduction, widened QRS complex, QRS-T fusion, loss of ST segment and tall tented T waves.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 55
Correct
-
A 27-year-old female was admitted due to severe dehydration. The patient also complained of chest tightness, thus an ECG was requested. The ECG strip showed an isoelectric ST segment, upright T wave, with prominent U waves. What is the most likely electrolyte abnormality responsible for these ECG tracing?
Your Answer: Hypokalaemia
Explanation:U waves are prominent if it is >1-2mm or 25% of the height of the T wave. Abnormally prominent U waves are characteristically seen in severe hypokalaemia.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 56
Incorrect
-
A 27-year-old woman has chronic low serum calcium levels. Which of the following conditions may be responsible for the hypocalcaemia in this patient?
Your Answer: Primary hyperparathyroidism
Correct Answer: Hypoparathyroidism
Explanation:Chronic hypocalcaemia is mostly seen in patients with hypoparathyroidism as a result of accidental removal or damage to parathyroid glands during thyroidectomy.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 57
Correct
-
During thyroidectomy, the recurrent laryngeal nerves are vulnerable to injury. Which of the following muscles will not be affected in cases where the recurrent laryngeal nerve is severed?
Your Answer: Cricothyroid
Explanation:All muscles of the larynx are supplied by the recurrent laryngeal nerve except for the cricothyroid which is supplied by the vagus nerve.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 58
Correct
-
The pleural cavity is the space between the two pulmonary pleurae which cover the lungs. What is the normal amount of pleural fluid?
Your Answer: 10 ml
Explanation:Pleural fluid is a serous fluid produced by the serous membrane covering normal pleurae. Most fluid is produced by the parietal circulation (intercostal arteries) via bulk flow and reabsorbed by the lymphatic system. The total volume of fluid present in the intrapleural space is estimated to be only 2–10 ml. A small amount of protein is present in intrapleural fluid. Normally, the rate of reabsorption increases as a physiological response to accumulating fluid.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 59
Correct
-
A 31-year-old woman is diagnosed with adrenal hyperplasia, and laboratory samples are taken to measure serum aldosterone and another substance. Which is most likely to be the other test that was prescribed to this patient?
Your Answer: Plasma renin
Explanation:The evaluation of a patient in whom hyperaldosteronism is first to determine that hyperaldosteronism is present (serum aldosterone) and, if it is present, to differentiate primary from secondary causes of hyperaldosteronism. The aldosterone-to-renin ratio (ARR) is the most sensitive means of differentiating primary from secondary causes of hyperaldosteronism as it is abnormally increased in primary hyperaldosteronism, and decreased or normal but with high renin levels in secondary hyperaldosteronism.
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This question is part of the following fields:
- Physiology
- Renal
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Question 60
Correct
-
A 65 year old man with a history of diabetes and hypertension presented with a stroke a few months ago severely affecting his speech and movement in the right arm and leg. A cerebral angiogram revealed a middle cerebral artery occlusion. A recent CT scan was done which revealed a 5 cm cystic space in his left parietal lobe. This lesion is a result of which of the following forms of resolution?
Your Answer: Liquefactive necrosis
Explanation:Characteristically, the brain will undergo liquefactive necrosis following ischaemic injury. This leaves a cystic space in that region which would show up on a CT scan. Atrophy would result in a generalized decrease in the brain size. Coagulative necrosis typically occurs in parenchymal organs e.g. the spleen or kidney which have a lower lipid content. Caseous necrosis is typical in granulomatous tuberculosis infection. Apoptosis will not form a cystic area as it is programmed cell death involving a individual cells. Gangrenous necrosis is characteristic of ischaemic injury of the lower limb and GI tract. Fibrinous necrosis results from necrotic damage to the blood vessels with the leaking of proteins into the vessel, appearing bright pink on H & E staining.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Neurology
- Pathology
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Question 61
Correct
-
A 65-year-old female is taking different medications for various medical conditions. Which medication would most likely predispose the patient to develop hyperkalaemia?
Your Answer: Spironolactone
Explanation:The most important potential side effect of spironolactone is hyperkalaemia (high potassium levels), which, in severe cases, can be life-threatening. Hyperkalaemia in these patients can present as a non anion-gap metabolic acidosis.Â
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 62
Correct
-
Which of these antibiotics is the first choice treatment for infections caused by Pseudomonas aeruginosa?
Your Answer: Piperacillin
Explanation:Piperacillin is an extended-spectrum beta-lactam antibiotic of the ureidopenicillin class. It is normally used with a beta-lactamase inhibitor such as tazobactam. The combination has activity against many Gram-positive and Gram-negative pathogens and anaerobes, including Pseudomonas aeruginosa. Piperacillin is sometimes referred to as an anti-pseudomonal penicillin.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 63
Correct
-
A 50-year old lady presented to the clinic with chronic pain in the abdomen. On physical examination, she was found to be pale. Further investigations revealed a decrease in both serum iron and total iron-binding capacity, along with an increase in serum ferritin. These findings are seen in:
Your Answer: Anaemia of chronic disease
Explanation:Anaemia of chronic disease is characterized by low serum iron, iron-binding capacity and saturation with increased ferritin (storage iron). Haemolytic anaemia is characterized by normal iron levels as the haemoglobin released from the haemolysed red blood cells is recycled. Anaemia due to chronic blood loss leads to low serum iron, low ferritin and high total iron-binding capacity (TIBC). Malabsorption, especially with duodenal involvement can also lead to iron deficiency anaemia with low ferritin and high TIBC. Megaloblastic anaemia due to vitamin B12 and folate deficiency is not associated with abnormalities in metabolism of iron.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 64
Correct
-
Most of the coagulation factors are serine proteases. Which of the following is not one of them?
Your Answer: Factor XIII
Explanation:Serine protease coagulation factors include: thrombin, plasmin, Factors X, XI and XII. Factor VIII and factor V are glycoproteins and factor XIII is a transglutaminase.
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This question is part of the following fields:
- General
- Physiology
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Question 65
Correct
-
A 40-year old gentleman underwent a computed tomographic scan for the abdomen to rule out blunt abdominal trauma, after a vehicular accident. The scan revealed no abnormal finding except for a 1 cm-sized cortical mass in the left adrenal gland. The doctor-on-call decided to not intervene for this mass because it was likely to be a:
Your Answer: Non-functioning adrenal adenoma
Explanation:Adrenal adenomas are common, benign lesions which are asymptomatic and seen in 10% of population. Usually detected incidentally on Computed tomography (‘incidentaloma’), only around 1 in 10,000 are malignant (adenocarcinoma). Adrenal adenomas rarely need to be investigated, especially if they are homogenous and less than 3 cm in diameter. Follow-up imaging can be done after an interval of 3-6 months to assess any change in size. Some adenomas can secrete cortisol (leading to Cushing syndrome), or aldosterone (leads to Conn syndrome) or androgens (leading to hyperandrogenism).
Haematomas and simple cysts are not usually seen in adrenal gland. Infection due to Histoplasma capsulatum is usually bilateral and leads to multiple granulomas. Adrenal metastasis will usually demonstrate a lung primary and the adrenal lesions will be often multiple and larger than 1 cm.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 66
Incorrect
-
Action potentials are used extensively by the nervous system to communicate between neurones and muscles or glands. What happens during the activation of a nerve cell membrane?
Your Answer: Potassium ions flow inward
Correct Answer: Sodium ions flow inward
Explanation:During the generation of an action potential, the membrane gets depolarized which cause the voltage gated sodium channels to open and sodium diffuses inside the neuron, resulting in the membrane potential moving towards a positive value. This positive potential will then open the voltage gated potassium channels and cause more K+ to move out decreasing the membrane potential and restoring the membrane potential to its resting value.
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This question is part of the following fields:
- General
- Physiology
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Question 67
Correct
-
Whilst snorkelling, a 30-year old gentleman has the respiratory rate of 10/min, tidal volume of 550 ml and an effective anatomical dead space of 250 ml. Which of the following will bring about a maximum increase in his alveolar ventilation?
Your Answer: A 2x increase in tidal volume and a shorter snorkel
Explanation:Alveolar ventilation = respiratory rate × (tidal volume − anatomical dead space volume). Increase in respiratory rate simply causes movement of air in the anatomical dead space, with no contribution to the alveolar ventilation. By use of a shorter snorkel, the effective anatomical dead space will decrease and will cause a maximum rise in alveolar ventilation along with doubling of tidal volume.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 68
Incorrect
-
A brain tumour causing blockage of the hypophyseal portal system is likely to result in an increased secretion of which of the following hormones?
Your Answer: Growth hormone
Correct Answer: Prolactin
Explanation:The hypophyseal portal system links the hypothalamus and the anterior pituitary. With the help of this system, the anterior pituitary receives releasing and inhibitory hormones from the hypothalamus and regulates the action of other endocrine glands. One of the inhibitory hormones carried by this system is the prolactin-inhibitory hormone. In the absence of this hormone which might occur in case of a blockage of the system, prolactin secretion increases to about three times normal levels.
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This question is part of the following fields:
- Endocrinology
- Physiology
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Question 69
Incorrect
-
A medical student is told a substance is freely filtered but is not metabolised, secreted, or stored in the kidney. It has a plasma concentration of 1000 mg/l and its urine excretion rate is 25 mg/min, and the inulin clearance is 100 ml/min. What is the rate of tubular reabsorption of the substance?
Your Answer: 35 mg/min
Correct Answer: 75 mg/min
Explanation:Reabsorption or tubular reabsorption is the process by which the nephron removes water and solutes from the tubular fluid (pre-urine) and returns them to the circulating blood. To calculate the reabsorption rate of substance Z we use the following equation: excretion = (filtration + secretion) – reabsorption. As this substance is freely filtered, its filtration rate is equal to that of inulin. So 25 = (100 + 0) – reabsorption. Reabsorption = 100 – 25 therefore reabsorption = 75 mg/min.
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This question is part of the following fields:
- Physiology
- Renal
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Question 70
Incorrect
-
Which of the following abnormalities can be seen in patients with hypermagnesemia?
Your Answer: Generalised seizures
Correct Answer: Respiratory depression
Explanation:Hypermagnesemia is an electrolyte disturbance in which there is a high level of magnesium in the blood. It is defined as a level greater than 1.1 mmol/L. Symptoms include weakness, confusion, decreased breathing rate, and cardiac arrest.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 71
Incorrect
-
Which of the following substances is most likely to cause pulmonary vasodilatation?
Your Answer: Endothelin
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.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 72
Incorrect
-
Which among the following vertebrae marks the lowest extent of the superior mediastinum?
Your Answer: Third thoracic
Correct 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.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 73
Incorrect
-
Which of the following will be affected by a lesion in the posterior column-medial lemniscus system?
Your Answer: Visual acuity
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.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 74
Incorrect
-
Which of the following clinical signs will be demonstrated in a case of Brown-Séquard syndrome due to hemisection of the spinal cord at mid-thoracic level?
Your Answer: Ipsilateral spastic paralysis, contralateral loss of vibration and proprioception (position sense) and contralateral loss of pain and temperature sensation beginning one or two segments below the lesion
Correct Answer: Ipsilateral spastic paralysis, ipsilateral loss of vibration and proprioception (position sense) and contralateral loss of pain and temperature sensation beginning one or two segments below the lesion
Explanation:Brown–Séquard syndrome results due to lateral hemisection of the spinal cord and results in a loss of motricity (paralysis and ataxia) and sensation. The hemisection of the cord results in a lesion of each of the three main neural systems: the principal upper motor neurone pathway of the corticospinal tract, one or both dorsal columns and the spinothalamic tract. As a result of the injury to these three main brain pathways the patient will present with three lesions. The corticospinal lesion produces spastic paralysis on the same side of the body (the loss of moderation by the upper motor neurons). The lesion to fasciculus gracilis or fasciculus cuneatus results in ipsilateral loss of vibration and proprioception (position sense). The loss of the spinothalamic tract leads to pain and temperature sensation being lost from the contralateral side beginning one or two segments below the lesion. At the lesion site, all sensory modalities are lost on the same side, and an ipsilateral flaccid paralysis.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 75
Incorrect
-
Tumours derived from all three germ-cell layers in new-borns usually occur in which of the following sites?
Your Answer: Testis
Correct Answer: Sacrococcygeal area
Explanation:A teratoma is a tumour with tissue or organ components resembling normal derivatives of more than one germ layer. It is derived from all three cell layers. The most common location of teratoma in new-born infants is in the sacrococcygeal area.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 76
Incorrect
-
A patient is unable to move their mandible to the left. Which muscle is affected in this case?
Your Answer: Right medial pterygoid muscle
Correct Answer: Right lateral pterygoid muscle
Explanation:Patients with paralysis of the right pterygoid muscle are unable to move their mandible laterally to the left.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 77
Incorrect
-
One sensitive indicator of heavy alcohol dependence is:
Your Answer: Decreased mean cell volume (MCV)
Correct Answer: Elevated serum gamma-glutamyl transpeptidase
Explanation:Elevated serum gamma-glutamyl transpeptidase (GGT) may be the only laboratory abnormality in patients who are dependent on alcohol. Heavy drinkers may also have an increased MCV.
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This question is part of the following fields:
- Hepatobiliary
- Physiology
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Question 78
Incorrect
-
Which of the following muscles is solely contained in the anterior triangle of the neck and divides the anterior triangle into three smaller triangles?
Your Answer: Sternocleidomastoid
Correct Answer: Digastric
Explanation:The digastric muscle is a small muscle located under the jaw. It lies below the body of the mandible, and extends, in a curved form, from the mastoid process to the symphysis menti. The digastric divides the anterior triangle of the neck into three smaller triangles:
– The submaxillary triangle, bounded above by the lower border of the body of the mandible and a line drawn from its angle to the sternocleidomastoid, below by the posterior belly of the digastric and the stylohyoid and in front by the anterior belly of the digastric
– The carotid triangle, bounded above by the posterior belly of the digastric and stylohyoid, behind by the sternocleidomastoid and below by the omohyoid
– The suprahyoid or submental triangle, bounded laterally by the anterior belly of the digastric, medially by the midline of the neck from the hyoid bone to the symphysis menti and inferiorly by the body of the hyoid bone.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 79
Incorrect
-
During hysterectomy, the ureter is most likely to be ligated when a surgeon is clamping the?
Your Answer: Broad ligaments
Correct Answer: Uterine arteries
Explanation:The ureter forms the posterior boundary of a shallow depression which lodges the ovary and then runs medially and forward on the lateral aspect of the uterine cervix and upper part of the vagina to reach the fundus of the bladder. It is also situated about 2cm from the side of the cervix of the uterus. The relationship of the ureters and uterine arteries is of clinical significance because the arteries are at risk of iatrogenic injury during hysterectomy.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 80
Correct
-
Which of the following malignancies is likely to have the best prognosis?
Your 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.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 81
Incorrect
-
Which of the following statements is true regarding the umbilical cord?
Your Answer: Is covered by a layer of endoderm
Correct Answer: Is filled with jelly of Wharton
Explanation:The umbilical cord that connects the fetus to the placenta is about 50cm long. This tissue consists of the body stalk and vitelline duct. The former containing the allantoic diverticulum and the umbilical vessels. The latter contains the connection linking the digestive tube and the yolk sac. This cord is wrapped by stratum of ectoderm and gelatinous tissue or jelly of Wharton. The right umbilical vein plus the vitelline vessels and ducts disappear and this at birth the cord has three vessels which are the umbilical vein and two umbilical arteries.
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This question is part of the following fields:
- Anatomy
- Embryology
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Question 82
Correct
-
A 27 year old women had developed a darker complexion following a vacation to India. She had no erythema or tenderness. Her skin colour returned to normal over a period of 1 month. Which of the these substances is related to the biochemical change mentioned above?
Your Answer: Tyrosine
Explanation:The tanning process can occur due to UV light exposure as a result of oxidation of tyrosine to dihydrophenylalanine with the help of the tyrosinase enzyme within the melanocytes. Hemosiderin can impart a brown colour due to breakdown of RBC but its usually due to a trauma and is known as haemochromatosis.
Lipofuscin gives a golden brown colour to the cell granules not the skin.
Homogentisic acid is part of a rare disease alkaptonuria, with characteristic black pigment deposition within the connective tissue.
Copper can impart a brown golden colour, but is not related to UV light exposure.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 83
Incorrect
-
A man came to the hospital complaining of a sensation of pins and needles in the dorsum of the thumb and digits 1 and 2. On further examination they found that he had weakness in wrist dorsiflexion and finger extension. Which nerve do you think is injured in this case?
Your Answer: Median
Correct Answer: Radial
Explanation:The radial nerve can be injured in multiple sites along its course in the upper limb, and each site has its own presentation. The major complaint is wrist drop which if high above the elbow, can cause numbness of the forearm and hand. It can last for several days or weeks. The most common site of compression for the radial nerve is at the proximal forearm in the area of the supinator muscles.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 84
Correct
-
A 40 year old woman, who is under anaesthesia for an elective procedure, received an antibiotic injection. She immediately developed a rash and her airway constricted raising the airway pressure. Which mechanism is responsible for this reaction?
Your Answer: Type I hypersensitivity
Explanation:Type I hypersensitivity reaction is an immediate reaction that occurs due to binding of the antigen with antibodies attached to mast cells in a previously sensitized person. It has an immediate phase, which is characterised by vasodilation, leakage of plasma, smooth muscle spasm, or glandular secretions. This manifests in about 5-30 min and usually resolves within 60 mins. The delayed phase follows after 24 hours and can persist up to several days. It is due to infiltration of eosinophils, neutrophils, basophils and CD4+ cells and leads to tissue destruction. The nature of the reaction varies according to the site. It can take the form of skin allergy, hives, allergic rhinitis, conjunctivitis, bronchial asthma or food allergy.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 85
Correct
-
Which of the following foramen provides passage of the facial nerve?
Your Answer: Internal acoustic meatus
Explanation:The internal auditory meatus provides a passage through which the vestibulocochlear nerve, the facial nerve, and the labyrinthine artery (an internal auditory branch of the basilar artery) can pass from inside the skull to structures of the inner ear and face.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 86
Incorrect
-
A 60-year old patient presenting with squamous cell carcinoma of the anal canal was brought in to the oncology ward for chemotherapy. In which of the following lymph nodes of this patient would you likely find metastases?
Your Answer: Periaortic
Correct Answer: Internal iliac
Explanation:The efferent lymphatics from the anal canal proceed to the internal iliac lymph nodes. This would most likely form the site of enlargement in the lymphatics.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 87
Correct
-
A mechanic sustained a deep laceration to his right cubital fossa which resulted in him unable to move the proximal radioulnar joint of his right arm. Which muscles was affected?
Your Answer: Pronator teres
Explanation:The correct answer is the pronator teres muscle. This muscle arises from 2 heads of origin: the humerus and ulnar. Between the 2 heads is the site of entrance of median nerve to the forearm. This muscle acts on the proximal radio-ulnar joint to rotate the radius on the ulna, otherwise known as pronation. It also assists in forearm flexion if the radius is fixed.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 88
Correct
-
The chest X-ray of a 72 year old patient reveals the presence of a round lesion containing an air-fluid level in the left lung. These findings are most probably suggestive of:
Your Answer: Lung abscess
Explanation:Lung abscesses are collections of pus within the lung that arise most commonly as a complication of aspiration pneumonia caused by oral anaerobes. Older patients are more at risk due to poor oral hygiene, gingivitis an inability to handle their oral secretions due to other diseases. Chest X-ray most commonly reveals the appearance of an irregularly shaped cavity with an air-fluid level.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 89
Incorrect
-
The oesophagus is an important part of the alimentary canal. It receives blood from various arteries in the body. Which one of the following is an artery that will lead to some level of ischaemia to the oesophagus when ligated?
Your Answer: Superior mesenteric
Correct Answer: Left inferior phrenic
Explanation:The oesophagus receives its blood supply from the following arteries: the inferior thyroid branch of the thyrocervical trunk, the descending thoracic aorta, the left gastric branch of the coeliac artery and the from the left inferior phrenic artery of the abdominal aorta. Hence ligation of the left inferior phrenic will lead to ischemia to some portions of the oesophagus.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 90
Correct
-
A lad involved in a road traffic accident is rushed to casualty where physical examination reveals that he has limited extension of his right humerus. Which of the following nerves is most likely to have been injured?
Your Answer: Thoracodorsal nerve
Explanation:Extension of the humerus is a function of the latissimus dorsi. This muscle is supplied by the thoracodorsal nerve which is a branch of the posterior cord of the plexus whose fibres are derived from cranial nerves V, VI and VII.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 91
Correct
-
Which of the following is a fact worth noting about the development of the spleen?
Your Answer: It develops in the dorsal mesogastrium
Explanation:The spleen in the human embryo arises in week 5 of intrauterine life. It appears as a proliferating mesenchyme above the pancreas. The spleen is one the organs that develops in the dorsal mesogastrium. When the stomach changes its position during development, the spleen is made to move behind the stomach and stays in contact with the left kidney. The spleen is found within the peritoneum of the abdominal cavity thus it is an intraperitoneal organ.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 92
Correct
-
A 45 year old women has a 4 cm non tender mass in her right breast which is fixed to the chest wall. Another 2cm non-tender mass is palpable in the left axilla. Chest x ray reveals multiple nodules ranging from 0.5 - 0.2 cm in both the lungs. What is the stage of her disease?
Your Answer: T4 N1 M1
Explanation:This woman has an invasive primary tumour mass with axillary node and lung metastases, making this stage T4 N1 M1. Looking at the other stems, T1 N1 M0 signifies a small primary cancer with nodal metastases but no distant metastases; T1 N0 M1 signifies a small primary cancer with no lymph node metastases but with distant metastases; T2 N1 M0 signifies a larger primary cancer with nodal metastases but no distant metastases; and T3 N0 M0 indicates a larger primary cancer with no metastases to either lymph nodes or to distant sites.
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This question is part of the following fields:
- Neoplasia; Female Health
- Pathology
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Question 93
Correct
-
What best describes the muscles of the posterior compartment of the leg?
Your Answer: One of the posterior compartment leg muscles laterally rotates the femur
Explanation:The muscles of the back of the leg are subdivided into two groups: superficial and deep. Superficial muscles include gastrocnemius, soleus and plantaris and are the chief extensors of the foot at the ankle joint. Deep muscles include the tibialis posterior, flexor hallucis longus, flexor digitorum longus and popliteus
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 94
Incorrect
-
Which muscle extends to form the cremasteric muscle?
Your Answer: Dartos muscle
Correct Answer: Internal abdominal oblique muscle
Explanation:The cremasteric muscle is a thin layer of muscle composed of several fasciculi that originate from the middle of the inguinal ligament. At its point of origin the fibres are continuous with the fibres of internal oblique and sometimes with the transversus abdominis. It then passes along the lateral side of the spermatic cord and descends with it through the superficial inguinal ring on the front and sides of the cord.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 95
Correct
-
Selective destruction of which of the following cells will affect antibody synthesis?
Your Answer: Plasma cells
Explanation:Plasma cell are memory cells. After the antigen Is engulfed by the B cells it is presented to the CD4+ helper cells via the MCH II receptor and this leads to their activation which in turn stimulates the B cells to form antibodies against that specific antigen. Some B cells differentiate into plasma cells also called memory cells that get activated after subsequent infection.
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This question is part of the following fields:
- General
- Physiology
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Question 96
Correct
-
What is the primary function of the Kupffer cells found in the liver?
Your Answer: Recycling of old red blood cells
Explanation:Kupffer cells found in the liver are part of the monocyte-reticular system. They are specialised macrophages and primarily function to recycle old and damaged RBCs. The RBCs are phagocytosed and the haemoglobin is broken down into haem and globin. The haem is further broken down into iron that is recycled and bilirubin that is conjugated with glucuronic acid and excreted in the bile.
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This question is part of the following fields:
- Inflammation & Immunology; Hepatobiliary
- Pathology
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Question 97
Incorrect
-
A 20-year old involved in a brawl was stabbed in the anterior chest in a structure that is in close proximity to where the first rib articulates with the sternum. What is the structure that was most likely injured?
Your Answer: Sternal angle
Correct Answer: Sternoclavicular joint
Explanation:The first rib articulates with the sternum right below the sternoclavicular joint.
The sternal angle articulates with the costal cartilage of the second rib.
The nipple is found between the fourth and the fifth ribs, in the fourth intercostal space.
The xiphoid process is located right below the point of articulation of the costal cartilage of rib 7 with the sternum.
The root of the lung is the part of the lung where neurovascular structures enter and leave the lung.
Acromioclavicular joint is the point of articulation between the acromion process and the clavicle, near the shoulder.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 98
Correct
-
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: 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.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 99
Correct
-
A 43-year-old diabetic man complains of headaches, palpitations, anxiety, abdominal pain and weakness. He is administered sodium bicarbonate used to treat:
Your Answer: Metabolic acidosis
Explanation:Sodium bicarbonate is indicated in the management of metabolic acidosis, which may occur in severe renal disease, uncontrolled diabetes, circulatory insufficiency due to shock or severe dehydration, extracorporeal circulation of blood, cardiac arrest and severe primary lactic acidosis. Bicarbonate is given at 50-100 mmol at a time under scrupulous monitoring of the arterial blood gas readings. This intervention, however, has some serious complications including lactic acidosis, and in those cases, should be used with great care.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 100
Correct
-
A 56-year-old woman complains of back pain, muscle spasms, weakness, and a burning sensation that radiates from her left hip to her toes. What's the most likely diagnosis?
Your Answer: Herniated nucleus pulposus
Explanation:A herniated disk will produce sensory disturbances, causing pain that radiates along the course of the sciatic nerve which is typically burning or stabbing, with or without back pain. The herniation is usually caused by age-related degeneration although trauma, injuries, or straining may also trigger it.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 101
Correct
-
Which of the following arteries, that runs on the superior aspect of the first part of the duodenum, forms the lower boundary of the epiploic foramen (also known as the foramen of Winslow)?
Your Answer: Hepatic
Explanation:The epiploic foramen is an important anatomical opening that allows for the communication between the greater peritoneal sac and the lesser peritoneal sac. Its boundaries are formed; superiorly by the caudate lobe of the liver, anteriorly by the hepatoduodenal ligament (containing the components of the portal triad), inferiorly by the first part of the duodenum and posteriorly by the peritoneum covering the inferior vena cava. The superior aspect of the first part of the duodenum, which forms the inferior boundary of the foramen of Winslow, forms the course of the hepatic artery before it ascends to the porta hepatis where it divides into its right and left branches.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 102
Incorrect
-
Which of the following muscle divide the posterior triangle of the neck into the occipital and the subclavian triangle?
Your Answer: Posterior belly of the digastric
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 103
Incorrect
-
One of the following structures is contained in the anterior compartment of the lower leg. Which is it?
Your Answer: Superficial peroneal nerve
Correct Answer: Extensor hallucis muscle
Explanation:The lower leg is made up of four fascial compartments separated from one another by septa that contain the muscles of the lower leg. The four compartments are ; anterior, lateral, deep posterior and superficial posterior compartments.
These are the compartments and there contents:
i) Anterior compartment: Tibialis anterior muscle, extensor hallucis longus muscle, extensor digitorum longus muscle, peroneus tertius muscles, deep fibular nerve and anterior tibial blood vessels
ii) Lateral compartment: Fibularis longus muscle, brevis muscles and superficial fibular nerve
iii) Deep posterior compartment: Tibialis posterior m., flexor hallucis longus m., flexor digitorum longus m. ,popliteus m. , tibial nerve, posterior tibial artery and posterior tibial vessels such as the fibular artery.
iv) Superficial posterior compartment: Gastrocnemius m., soleus m., plantaris m., medial sural cutaneous nerve
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 104
Incorrect
-
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: Facial
Correct 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.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 105
Correct
-
Multiple cells were labelled using a fluorescent dye that doesn’t cross the cell membrane. One cell in the middle was bleached with a light that destroys the dye, but the cell soon recovers its stain. The presence of which structures best explains this?
Your Answer: Gap junctions
Explanation:Gap junctions are attachments between cells that permit intercellular communication e.g. they permit current flow and electrical coupling between myocardial cells. They allow direct electrical transmission among cells and also permit certain substance to pass through as well. They are either homotypic, formed by two identical hemichannels or heterotypic, formed by different hemichannels.
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This question is part of the following fields:
- General
- Physiology
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Question 106
Incorrect
-
An old man presented with atrophy of the thenar eminence despite the sensation over it still being intact. What is the injured nerve in this case?
Your Answer: Ulnar nerve
Correct Answer: Median nerve
Explanation:Atrophy of the thenar muscles means injury to the motor supply of these muscles. The nerve that sends innervation to it is the median nerve. But the median nerve does not provide sensory innervation to the overlying skin so sensation is spared.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 107
Correct
-
A 63-year old lady presents with pain in multiple bones and renal failure. On enquiry, there is history of recurrent pneumonia in the past. What will be the likely finding on her bone marrow biopsy?
Your Answer: Plasma cells
Explanation:Multiple myeloma is a plasma cell malignancy that produce excessive monoclonal immunoglobulins. The disease presents with bone pains, renal dysfunction, increased calcium, anaemia and recurrent infections. Diagnosis is by demonstrating the presence of M-protein in urine or serum, lytic bone lesions, light chain proteinuria or excessive plasma cells on marrow biopsy.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 108
Incorrect
-
Infection to all of the following will lead to enlargement of the superficial inguinal lymph nodes, except for:
Your Answer: Penile urethra
Correct Answer: Ampulla of the rectum
Explanation:The superficial inguinal lymph nodes form a chain immediately below the inguinal ligament. They receive lymphatic supply from the skin of the penis, scrotum, perineum, buttock and abdominal wall below the level of the umbilicus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 109
Incorrect
-
A 41 year old women presents with a history of carcinoma involving the right breast with enlarged axillary nodes on the same side. She underwent mastectomy and axillary node clearance. These were sent for histopathological examination. They showed no signs of metastasis. What could be cause of this enlargement in the lymph nodes?
Your Answer: Secondary deposits
Correct Answer: Sinus histiocytosis
Explanation:Sinus histiocytosis also referred to as reticular hyperplasia, refers to the enlargement, distention and prominence of the sinusoids of the lymph nodes. This is a non-specific form of hyperplasia characteristically seen in lymph nodes that drain tumours. The endothelial lining of the lymph node becomes markedly hypertrophied, along with an increase in the number of macrophages which results in the distortion, distention and enlargement of the sinus. In this scenario there is no evidence that an infection or another malignancy could account for the enlargement. Paracortical lymphoid hyperplasia is caused by an immune response.
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This question is part of the following fields:
- Inflammation & Immunology; Female Health
- Pathology
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Question 110
Correct
-
A 19 year old male patient exhibiting signs of shock was brought to the casualty after he had fallen from the 3rd floor of a building. An examination carried out revealed tenderness on the left mid-posterior axillary line and low blood pressure. Further palpation revealed a large swelling that protruded downward and medially below the left costal margin. X-rays showed that the 9th and the 10th ribs were fractured near their angles. Considering these results, which abdominal organ was likely injured by the fractured ribs.
Your Answer: Spleen
Explanation:The spleen, left kidney, stomach, the splenic flexure of the colon and the suprarenal glands are all in the same quadrant- the left upper quadrant. However, the spleen is the most readily injured organ when there is fracture to the 10th, 11th and the 12th ribs because of its close association with these ribs. This patient exhibits a great indication of a ruptured spleen (tenderness on the left mid and posterior axillary line). The spleen is a thin capsulated organ with a spongy parenchyma, allowing it to bleed profusely in the event of injury. The liver, head of the pancreas and the duodenum are all in the right upper quadrant.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 111
Correct
-
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: 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 112
Correct
-
During an operation to repair an indirect inguinal hernia, it is noticed that the hernial sac is protruding out of the superficial inguinal ring. The superficial inguinal ring is an opening in which structure?
Your Answer: External abdominal oblique aponeurosis
Explanation:The superficial inguinal ring is an opening in the aponeurosis of the external oblique just above and lateral to the pubic crest. The opening is oblique and corresponds to the fibres of the aponeurosis. It is bound inferiorly by the pubic crest, on either side by the margins of the opening in the aponeurosis and superiorly by the curved intercrural fibres.
The inferior crus is formed by the portion of the inguinal ligament that is inserted into the pubic tubercle.
The falx inguinalis is made of arching fibres of the transversalis fascia and the internal abdominal oblique muscle. It forms the posterior wall of the inguinal canal.
The internal abdominal oblique forms the root of the inguinal canal.
Scarpa’s and Camper’s fascia are the membranous and fatty layers, respectively of subcutaneous fascia.
Transversalis fascia covers the posterior surface of the rectus abdominis muscle inferior to the arcuate line.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 113
Correct
-
A 35 year-old man presents with high grade fever for 7 days after returning from a trip to India. He tested positive for widal test. What is the most likely organism that caused his fever?
Your Answer: Salmonella typhi
Explanation:Typhoid fever is caused by virulent bacteria called Salmonella typhi. Salmonella typhi spread through contaminated food or water and occasionally through direct contact with someone who is infected.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 114
Correct
-
A patient with a long standing lower motor neuron lesion will have:
Your Answer: Muscle wasting
Explanation:Lower motor neurons (LMNs) connect the brainstem and spinal cord to muscle fibres. Damage to lower motor neurons is indicated by abnormal electromyographic potentials, fasciculations, paralysis, weakening and wasting of skeletal muscles.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 115
Incorrect
-
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: Proximal tubule
Correct 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 116
Correct
-
A patient underwent surgical excision of mass in the right carotid triangle. One day after the surgery patient complained of numbness of the skin over the right side of the neck. Injury to the cervical plexus of nerves is suspected. What is the possible nerve affected in this patient?
Your Answer: Transverse cervical
Explanation:The transverse cervical nerve (superficial cervical or cutaneous cervical) arises from the second and third spinal nerves, turns around the posterior border of the sternocleidomastoid and, passing obliquely forward beneath the external jugular vein to the anterior border of the muscle, it perforates the deep cervical fascia, and divides beneath the platysma into the ascending and descending branches. It provides cutaneous innervation to this area.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 117
Incorrect
-
Intravenous diazepam was administered to a man who was brought to the emergency department with status epilepticus. He was administered 15 l/min oxygen via a reservoir bag mask. Blood investigations showed sodium = 140 mmol/l, potassium = 4 mmol/l and chloride = 98 mmol/l. His arterial blood gas analysis revealed pH 7.08, p(CO2)= 61.5 mmHg, p(O2) = 111 mmHg and standard bicarbonate = 17 mmol/l. This patient had:
Your Answer: Respiratory acidosis
Correct Answer: Mixed acidosis
Explanation:Acidosis with high p(CO2) and low standard bicarbonate indicates mixed acidosis. Lower p(O2) is due to breathing of 70% oxygen. The prolonged seizures lead to lactic acidosis and the intravenous diazepam is responsible for the respiratory acidosis. Treatment includes airway manoeuvres and oxygen, assisted ventilation if needed, and treatment with fluids.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 118
Correct
-
Which of the following is the most likely cause of massive splenomegaly in a 35-year old gentleman?
Your Answer: Myelofibrosis
Explanation:Causes of massive splenomegaly include chronic myelogenous leukaemia, chronic lymphocytic leukaemia, lymphoma, hairy cell leukaemia, myelofibrosis, polycythaemia vera, sarcoidosis, Gaucher’s disease and malaria.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 119
Correct
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A 27-year-old HIV patient started on an antifungal agent. Which antifungal agent that inhibits the biosynthesis of fungal ergosterol was given to the patient?
Your Answer: Ketoconazole
Explanation:Ketoconazole is a synthetic imidazole antifungal drug used primarily to treat fungal infections. It inhibits the biosynthesis of ergosterol by blocking demethylation at the C14 site of the ergosterol precursor. Amphotericin B and Nystatin impair permeability of the cell membrane. Flucytosine interferes with DNA synthesis, while the target of griseofulvin is the microtubules
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 120
Correct
-
During uterogrowth, the second pharyngeal arch gives rise to which structures?
Your 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
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This question is part of the following fields:
- Anatomy
- Embryology
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Question 121
Correct
-
Which of the cranial nerves is responsible for touch sensation on the skin over the maxilla region and the mandible?
Your Answer: Trigeminal
Explanation:The sensation of the face is provided by the trigeminal nerve which is cranial nerve V. It is also responsible for other motor functions such as biting and chewing. The trigeminal nerve has three branches; the ophthalmic nerve (V1), the maxillary nerve((V2) and the mandibular nerve (V3). These three branches exit the skull through separate foramina, namely; the superior orbital fissure, the foramen rotundum and the foramen ovale respectively. The mnemonic for this is ‘Standing room only’. The sensory fibres of the maxillary nerve are distributed to the lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges. The sensory fibres of the mandibular nerve are distributed to the lower lip, the lower teeth and gums, the floor of the mouth, the anterior two-thirds of the tongue, the chin and jaw (except the angle of the jaw, which is supplied by C2–C3), parts of the external ear, and parts of the meninges. The mandibular nerve carries touch/ position and pain/temperature sensation from the mouth. The sensory fibres of the ophthalmic nerve are distributed to the scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose), the nasal mucosa, the frontal sinuses and parts of the meninges (the dura and blood vessels). The sensory fibres of the maxillary nerve are distributed to the lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 122
Correct
-
Cancer of the testis most likely metastases to which set of lymph nodes?
Your Answer: Aortic
Explanation:The lymphatic drainage of an organ is related to its blood supply. The lymphatic drainage of the testis drains along the testicular artery to reach the lymph nodes along the aorta.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 123
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 124
Incorrect
-
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 125
Incorrect
-
A 56-year-old woman weighs 75 kg. In this patient, total body water, intracellular fluid and extracellular fluid are respectively:
Your Answer: 65 l, 2.5 l, 2.5 l
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.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 126
Incorrect
-
The pterygoid plexus receives tributaries from which of the following veins?
Your Answer: External jugular vein
Correct Answer: Maxillary vein
Explanation:The pterygoid plexus of veins is the main venous component associated with the infratemporal fossa. It receives tributaries corresponding to the branches of the internal maxillary artery. This plexus communicates freely with the anterior facial vein; it also communicates with the cavernous sinus, by branches through the foramen of Vesalius, foramen ovale and foramen lacerum. The (internal) maxillary vein is a short trunk which accompanies the first part of the (internal) maxillary artery. It is formed by a confluence of the veins of the pterygoid plexus and passes backward between the sphenomandibular ligament and the neck of the mandible and unites with the temporal vein to form the posterior facial vein. It carries blood away from the infratemporal fossa.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 127
Correct
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A man had noticed weakness in his left arm causing flexion of the elbow and supination of the forearm. Which nerve in this case was injured?
Your Answer: Musculocutaneous
Explanation:The musculocutaneous nerve supplies the biceps brachii and the brachialis muscles. The first one flexes the elbow and the shoulder. It is also involved in supination. The brachialis muscle flexes the forearm. The injury to the musculocutaneous nerve results in paralysis of these muscles.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 128
Correct
-
A 35 year-old woman is undergoing thyroidectomy. The external laryngeal nerve may be injured whilst ligating this artery during the procedure due to its close relationship?
Your Answer: Superior thyroid artery
Explanation:The superior thyroid artery arises from the external carotid artery just below the level of the greater cornu of the hyoid bone and ends in the thyroid gland. This artery must be ligated at the thyroid when conducting a thyroidectomy. If the artery is severed, but not ligated, it will bleed profusely. In order to gain control of the bleeding, the surgeon may need to extend the original incision laterally to ligate the artery at its origin at the external carotid artery. The external laryngeal branch of the superior laryngeal nerve courses in close proximity to the superior thyroid artery, making it at risk for injury during surgery.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 129
Correct
-
Low molecular weight heparin (LMWH) has less side effects than heparin and is used in the prophylaxis and treatment of venous and arterial thrombotic disorders. Which of the following is LMWHs mechanism of action?
Your Answer: Inhibition of factor Xa
Explanation:Low molecular weight heparin (LMWH) is a anticoagulant that differs from normal heparin in that it has only short chains of polysaccharide. LMWH inhibits thrombin formation by converting antithrombin from a slow to a rapid inactivator of coagulation factor Xa.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 130
Incorrect
-
The line which divides the perineum into two triangles is connected to the?
Your Answer: Coccyx
Correct Answer: Ischial tuberosities
Explanation:The perineum has it’s deep boundaries in front of the pubic arch and the arcuate ligament of the pubis, behind the tip of the coccyx and on either side of the inferior rami of the pubis and ischium and the sacrotuberous ligament. It also corresponds to the outlet of the pelvis. A line drawn transversely across, in front of the ischial tuberosities divides the space into two portions, the posterior contains the termination of the anal canal and the anterior, contains the external urogenital organs.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 131
Correct
-
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: 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.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 132
Incorrect
-
Which of the following arteries branch from the deep femoral artery and course between the pectineus and iliopsoas muscles?
Your Answer: Obturator
Correct Answer: Medial femoral circumflex
Explanation:The medial femoral circumflex artery is an artery in the upper thigh that supplies blood to the head and neck of the femur. It arises from the deep femoral artery and winds around the medial side of the femur. It passes first between pectineus and psoas major, and then between obturator externus and adductor brevis.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 133
Correct
-
Which foramen contains the vertebral artery?
Your Answer: Foramen magnum
Explanation:The foramen magnum is found in the most inferior part of the posterior cranial fossa. It is traversed by vital structures including the medulla oblongata. Its contents include the following: medulla oblongata, meninges, spinal root of the accessory nerve, vertebral arteries, anterior and posterior spinal arteries, tectorial membrane and alar ligaments.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 134
Incorrect
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A 30-year-old man is brought to the emergency department suffering from extreme dehydration, and subsequent hypotension and tachycardia. Which part of the kidney will compensate for this loss?
Your Answer: Distal convoluted tubule
Correct Answer: Collecting ducts
Explanation:The collecting duct system of the kidney consists of a series of tubules and ducts that physically connect nephrons to a minor calyx or directly to the renal pelvis. The collecting duct system is the last component of the kidney to influence the body’s electrolyte and fluid balance. In humans, the system accounts for 4–5% of the kidney’s reabsorption of sodium and 5% of the kidney’s reabsorption of water. At times of extreme dehydration, over 24% of the filtered water may be reabsorbed in the collecting duct system.
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This question is part of the following fields:
- Physiology
- Renal
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Question 135
Correct
-
A week after a renal transplant the patient received antilymphocyte globulins. Shortly after she developed fever and hypotension. Which of the following mechanisms is involved in this response?
Your Answer: Type III hypersensitivity
Explanation:Type III hypersensitivity is characterized by soluble immune complexes which are aggregations of IgG and IgM antibodies with antigens that deposit in different tissues e.g. the skin, joints, kidneys. They can then trigger an immune response by activating the complement cascade. This reaction can take hours to develop and examples include: immuno-complex glomerulonephritis, rheumatoid arthritis, SLE, subacute bacterial endocarditis, arthus reaction and serum sickness.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 136
Correct
-
A 48-year-old woman has a mass in her right breast and has right axillary node involvement. She underwent radical mastectomy of her right breast. The histopathology report described the tumour to be 4 cm in its maximum diameter with 3 axillary lymph nodes with evidence of tumour. The most likely stage of cancer in this patient is:
Your Answer: IIB
Explanation:Stage IIB describes invasive breast cancer in which: the tumour is larger than 2 centimetres but no larger than 5 centimetres; small groups of breast cancer cells — larger than 0.2 millimetre but not larger than 2 millimetres — are found in the lymph nodes OR the tumour is larger than 2 centimetres but no larger than 5 centimetres; cancer has spread to 1 to 3 axillary lymph nodes or to lymph nodes near the breastbone (found during a sentinel node biopsy) OR the tumour is larger than 5 centimetres but has not spread to the axillary lymph nodes.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 137
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.
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This question is part of the following fields:
- Anatomy
- Breast
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Question 138
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: Pectoralis minor
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.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 139
Correct
-
The specimen sent to the pathologist for examination was found to be benign. Which one of the following is most likely a benign tumour?
Your Answer: Warthin’s tumour
Explanation:Warthin’s tumour is also known as papillary cystadenoma lymphomatosum. It is a benign cystic tumour of the salivary glands containing abundant lymphocytes and germinal centres. It has a slightly higher incidence in males and most likely occur in older adults aged between 60 to 70 years. This tumour is also associated with smoking. Smokers have an eight-fold greater risk in developing the tumour compared to non-smokers.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 140
Correct
-
A surgeon performing a laparoscopic repair of an inguinal hernia visualizes a loop of bowel protruding through the abdominal wall to form a direct inguinal hernia. When this is viewed from the side of the abdomen with a laparoscope, in which region would the hernial sac be?
Your Answer: Medial inguinal fossa
Explanation:In a direct inguinal hernia, visceral contents exit the abdomen through a weak point in the fascia in the medial inguinal fossa i.e. the area between the medial and lateral umbilical folds. Such a hernia doesn’t pass through the deep inguinal ring or the lateral inguinal fossa. Note that direct hernias can go through the superficial inguinal ring, although rarely. The supravesical fossa, between the median and medial umbilical folds, is formed by a peritoneal reflection from the anterior abdominal wall onto the bladder and the retrovesical fossa is the region behind the urinary bladder.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 141
Incorrect
-
The anatomical course of the phrenic nerve passes over the following muscle in the neck?
Your Answer: Trapezius
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.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 142
Correct
-
A child defecates a few minutes after being fed by the mother. This is most likely due to:
Your Answer: Gastrocolic reflex
Explanation:The gastrocolic reflex is a physiological reflex that involves increase in colonic motility in response to stretch in the stomach and by-products of digestion in the small intestine. It is shown to be uneven in its distribution throughout the colon, with the sigmoid colon affected more than the right side of the colon in terms of a phasic response. Various neuropeptides have been proposed as mediators of this reflex, such as serotonin, neurotensin, cholecystokinin and gastrin.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 143
Correct
-
The annular ligament in the forearm:
Your Answer: Encircles the head of the radius
Explanation:The annular ligament forms about four-fifths of the osseofibrous ring and is attached to the anterior and posterior margins of the radial notch. It is a strong band of fibres which encircles the head of the radius retaining it in contact with the radial notch of the ulna. When it comes to its upper border, it blends with the anterior and posterior ligament of the elbow.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 144
Correct
-
A patient is diagnosed with lung cancer. His physician told him that his lung cancer type is aggressive. It can grow rapidly and may undergo early metastasis, however it is very sensitive to chemotherapy and radiotherapy. Which lung cancer type is most likely present
Your Answer: Small-cell carcinoma
Explanation:Small-cell lung carcinoma (SCLC) is a type of highly malignant cancer that most commonly arises within the lung. SCLC usually metastasizes widely very early on in the natural history of the tumour, and in nearly all cases responds dramatically to chemotherapy and/or radiotherapy. Surgery has no role in the treatment of this disease.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 145
Correct
-
A 29-year-old woman presents to the doctor complaining of cough, shortness of breath, fever and weight loss. Chest X-ray revealed bilateral hilar and mediastinal lymph node enlargement and bilateral pulmonary opacities. Non-caseating granulomas were found on histological examination. The most likely diagnosis is:
Your Answer: Sarcoidosis
Explanation:Sarcoidosis is an inflammatory disease of unknown aetiology that affects multiple organs but predominantly the lungs and intrathoracic lymph nodes. Systemic and pulmonary symptoms may both be present. Pulmonary involvement is confirmed by a chest X-ray and other imaging studies. The main histological finding is the presence of non-caseating granulomas.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 146
Correct
-
Which organ is responsible for the secretion of enzymes that aid in digestion of complex starches?
Your Answer: Pancreas
Explanation:α-amylase is secreted by the pancreas, which is responsible for hydrolysis of starch, glycogen and other carbohydrates into simpler compounds.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 147
Correct
-
During laparoscopic surgery to repair a direct inguinal hernia in a 68-year old man, the surgeon asked the registrar to look at the medial inguinal fossa to identify the direct inguinal hernia. To do so, she would have to look at the area that is between the:
Your Answer: Medial umbilical ligament and inferior epigastric artery
Explanation:The medial umbilical fold is made by the medial umbilical ligament-which is the obliterated portion of the umbilical artery, while the lateral umbilical fold is a fold of peritoneum over the inferior epigastric vessels. The median umbilical fold is a midline structure made by the median umbilical ligament i.e. the obliterated urachus. The medial inguinal fossa is the space on the inner abdominal wall between the medial umbilical fold and the lateral umbilical fold. It is place in the abdominal wall where there is an area of weak fascia i.e. the inguinal triangle through which direct inguinal hernias break through. The lateral inguinal fossa on the other hand is a space lateral to the lateral umbilical fold. Indirect inguinal hernias push through this space.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 148
Incorrect
-
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: Cupola
Correct 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.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 149
Correct
-
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: 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.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 150
Correct
-
The cranial nerves of the brain provide motor and sensory innervation to the structures of the head and neck. Which of the following cranial nerves provide only motor innervation?
Your Answer: Abducens
Explanation:The cranial nerves emerge directly from the brain and the brain stem. They provide sensory, motor or both motor and sensory innervation. Here is a summary of the cranial nerves and their function:
Olfactory – Purely sensory
Optic – Sensory
Oculomotor – Mainly motor
Trochlear – Motor
Trigeminal – Both sensory and motor
Abducens – Mainly motor
Facial – Both sensory and motor
Vestibulocochlear – Mostly sensory
Glossopharyngeal – Both sensory and motor
Vagus – Both sensory and motor
Accessory – Mainly motor
Hypoglossal – Mainly motor
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 151
Correct
-
An abdominal aortogram of a 59 year-old female with an abdominal aortic aneurysm shows occlusion of the inferior mesenteric artery. The patient, however, does not complain of any symptoms. Occlusion of the inferior mesenteric artery is rarely symptomatic because its territory is supplied by branches of the:
Your Answer: Middle colic artery
Explanation:The transverse colon is supplied by the middle colic artery which is a branch from the superior mesenteric artery. If the inferior mesenteric artery was occluded, branches from the middle colic may go to the marginal artery which supplies the descending colon, sigmoid colon and rectum.. Ileocolic and right colic arteries also branch from the superior mesenteric artery that supply the colon but the middle colic, which serves the more distal part of the colon is the better answer. The gastroduodenal artery branches off the common hepatic artery, which supplies part of the duodenum, pancreas and stomach. The splenic artery supplies the spleen, pancreas and curvature of the stomach.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 152
Correct
-
Whilst snorkelling, a 30-year old gentleman has the respiratory rate of 10/min, tidal volume of 550 ml and an effective anatomical dead space of 250 ml. What is his alveolar ventilation?
Your Answer: 3000 ml/min
Explanation:Alveolar ventilation is the amount of air reaching the alveoli per minute. Alveolar ventilation = respiratory rate × (tidal volume – anatomical dead space volume). Thus, alveolar ventilation = 10 × (550 − 250) = 3000 ml/min.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 153
Incorrect
-
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: Calcaneus
Correct Answer: Base of the fifth metatarsal
Explanation:The peroneus brevis muscle originates from the lower two-thirds of the lateral body of the fibula and has inserts at the base of the fifth metatarsal. Fractures to this bone are common and can be due to infection, trauma, overuse and repetitive use.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 154
Incorrect
-
A 55 year old man presented with a 4 day history of cough and fever. His sputum culture showed the presence of Strep pneumoniae. Which of the following substances produced by the inflammatory cells will result in effective clearance of this organism from the lung parenchyma?
Your Answer: Leukotriene
Correct Answer: Hydrogen peroxide
Explanation:Hydrogen peroxide is produced by myeloperoxidase to form a potent oxidant that eliminates bacteria, but is not effective in chronic granulomatous diseases.
Platelet activating factor will lead to the activation, adhesion and aggregation of platelets but will not directly kill bacteria.
Prostaglandins cause vasodilation but do not activate neutrophils.
Kallikrein promotes formation of bradykinin that leads to vasodilation.
Leukreines increase vascular permeability.
Cytokines are communicating molecules between immune cells but directly will not kill bacteria.
Interleukins will regulate the immune response.
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This question is part of the following fields:
- Inflammation & Immunology; Respiratory
- Pathology
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Question 155
Correct
-
A patient presents with loss of fine touch and sense of proprioception in the lower part of the body (below T6). He is likely to have a lesion involving:
Your Answer: Gracile nucleus
Explanation:The gracile nucleus is located in the medulla oblongata and is one of the dorsal column nuclei involved in the sensation of fine touch and proprioception. It contains second-order neurons of the dorsal column–medial lemniscus system, that receive inputs from sensory neurones of the dorsal root ganglia and send axons that synapse in the thalamus.
The gracile nucleus and fasciculus carry epicritic, kinaesthetic and conscious proprioceptive information from the lower part of the body (below the level of T6 in the spinal cord). Similar information from the upper part of body (above T6, except for face and ear) is carried by the cuneate nucleus and fasciculus. The information from face and ear is carried by the primary sensory trigeminal nucleus.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 156
Correct
-
A 66-year-old man complains of constant headaches. On physical examination, the only relevant sign is a dark brown mole located on left his arm which has grown in size over the years and is itchy and painful. A MRI of the brain revealed a solitary lesion at the grey-white junction in the right frontal lobe, without ring enhancement. This lesion is most likely to be:
Your Answer: Metastatic carcinoma
Explanation:The location of the mass at the grey–white junction is typical of a metastasis. The most frequent types of metastatic brain tumours originate in the lung, skin, kidney, breast and colon. These tumour cells reach the brain via the bloodstream. This patient is likely to have skin cancer, which caused the metastatic brain tumour.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 157
Incorrect
-
If a tumour is found in both lobes of the prostate, without nodal involvement or metastases, a histological grade of G2 and elevated PSA, what is the overall prostatic cancer stage?
Your Answer: Stage I
Correct Answer: Stage II
Explanation:The AJCC uses the TNM, Gleason score and PSA levels to determine the overall stage of prostatic cancer. This staging is as follows:
Stage I: T1, N0, M0, Gleason score 6 or less, PSA less than 10; or T2a, N0, M0, Gleason score 6 or less, PSA less than 10
Stage IIa: T1, N0, M0, Gleason score of 7, PSA less than 20; or T1, N0, M0, Gleason score of 6 or less, PSA at least 10 but less than 20; or T2a or T2b, N0, M0, Gleason score of 7 or less, PSA less than 20
Stage IIb: T2c, N0, M0, any Gleason score, any PSA; or T1 or T2, N0, M0, any Gleason score PSA of 20 or more; or T1 or T2, N0, M0, Gleason score of 8 or higher, any PSA
Stage III: T3, N0, M0, any Gleason score, any PSA Stage IV: T4, N0, M0,any Gleason score, any PSA; or any T, N1, M0,any Gleason score, any PSA; or Any T, any N, M1, any Gleason score, any PSA.
The patient in this case has a T2 N0 M0 G2 tumour, meaning it belongs in stage II
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This question is part of the following fields:
- Pathology
- Urology
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Question 158
Correct
-
A 50-year-old woman goes to the doctor complaining of myalgia, muscle cramps, and weakness; she is diagnosed with severe hypokalaemia. Which of the following is the most common cause of hypokalaemia?
Your Answer: Prolonged vomiting
Explanation:Potassium is one of the body’s major ions. Nearly 98% of the body’s potassium is intracellular. The ratio of intracellular to extracellular potassium is important in determining the cellular membrane potential. Small changes in the extracellular potassium level can have profound effects on the function of the cardiovascular and neuromuscular systems. Hypokalaemia may result from conditions as varied as renal or gastrointestinal (GI) losses, inadequate diet, transcellular shift (movement of potassium from serum into cells) and medications. The important causes of hypokalaemia are:
Renal losses: renal tubular acidosis, hyperaldosteronism, magnesium depletion, leukaemia (mechanism uncertain).
GI losses: vomiting or nasogastric suctioning, diarrhoea, enemas or laxative use, ileal loop.
Medication effects: diuretics (most common cause), β-adrenergic agonists, steroids, theophylline, aminoglycosides.
Transcellular shift: insulin, alkalosis.
Severe hypokalaemia, with serum potassium concentrations of 2.5–3 meq/l, may cause muscle weakness, myalgia, tremor, muscle cramps and constipation.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 159
Correct
-
Glucose is not secreted by the kidneys, and is filtered without a limit. What is the transport maximum for glucose?
Your Answer: 300 mg/dl
Explanation:Transport maximum (or Tm) refers to the point at which increases in concentration do not result in an increase in movement of a substance across a membrane. Glucose is not secreted, thus excretion = filtration – reabsorption. Both filtration and reabsorption are directly proportional to the concentration of glucose in the plasma. However, reabsorption has a transport maximum of about 300 mg/dl in healthy nephrons, while filtration has effectively no limit (within reasonable physiological ranges). So, if the concentration rises above 300 mg/dl, the body cannot retain all the glucose, leading to glucosuria. Glucosuria is nearly always caused by elevated blood glucose levels, most commonly due to untreated diabetes mellitus.
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This question is part of the following fields:
- Physiology
- Renal
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Question 160
Incorrect
-
A patient with Paget's disease of the bone is predisposed to developing which type of cancer?
Your Answer: Giant-cell tumour
Correct Answer: Osteosarcoma
Explanation:Paget’s disease of bone (PDB) is a focal disorder of bone. It is presumed benign in nature and mediated by abnormal osteoclast function. However osteosarcomas may occur in <1% of patients with Paget's disease of the bone. Osteosarcomas are osteogenic in origin, and consistently arise in sites of pagetic bone. This is not to be confused with Paget's disease of the breast.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 161
Correct
-
Painful erections along with deviation of the penis to one side when erect are seen in which of the following conditions?
Your Answer: Peyronie’s disease
Explanation:Peyronie’s disease leads to development of fibrous plaques in the penile soft tissue and occurs in 1% of men, most commonly affecting white males above 40 years age. It is a connective tissue disorder named after a French surgeon, François de la Peyronie who first described it. Symptoms include pain, hard lesions on the penis, abnormal curvature of erect penis, narrowing/shortening, painful sexual intercourse and in later stages, erectile dysfunction. 30% cases report fibrosis in other elastic tissues such as Dupuytren’s contractures of the hand. There is likely a genetic predisposition as increased incidence is noted among the male relatives of an affected individual.
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This question is part of the following fields:
- Pathology
- Urology
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Question 162
Correct
-
A 70-year-old man who was previously healthy develops a rapidly progressing neurological deficit. A MRI reveals a large, poorly defined mass with central necrosis in his left temporal lobe. What is the most likely diagnosis?
Your Answer: Glioblastoma multiforme
Explanation:Glioblastoma multiforme, or grade 4 astrocytoma, is the most common and aggressive primary brain tumour. They are formed by small areas of necrotising tissue surrounded by highly anaplastic cells. Most of them arise from the deep white matter of the brain and quickly infiltrate it, becoming very large before they are symptomatic. The most common symptom is progressive memory, personality or neurological deficit due to temporal and frontal lobe involvement. It is most common in men, and risk factors include: neurofibromatosis, tuberous sclerosis, Von Hippel-Lindau disease, Li-Fraumeni syndrome, and Turcot syndrome.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 163
Correct
-
A nerve is injured during a surgical operation to repair an inguinal hernia. It passes through the superficial inguinal ring. Which nerve is it most likely to be?
Your Answer: Ilioinguinal
Explanation:The ilioinguinal nerve doesn’t pass through the deep inguinal ring but enters the inguinal canal from the side and leaves by passing through the superficial ring thus it is at risk of injury during inguinal hernia repair.
The femoral branch of genitofemoral nerve travels lateral to the superficial inguinal ring.
The iliohypogastric nerve and the subcostal nerve travel superior to the inguinal canal and superficial inguinal ring.
The obturator nerve is a branch of the lumbar plexus that innervates the muscles of the thigh.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 164
Incorrect
-
Calculate the stroke volume in an adult male with the following parameters:
Heart rate 70 beats/min
Arterial [O2] 0.24 ml O2/min
Venous [O2] 0.16 ml O2/mi
Whole body O2 consumption 500 ml/min
Pulmonary diastolic pressure 15 mmHg
Pulmonary systolic pressure 25 mmHg
Wedge pressure 5 mmHg.Your Answer: 100 ml
Correct Answer: 90 ml
Explanation:Fick’s principle states that, VO2 = (CO × CAO2) – (CO × CVO2) where VO2 = oxygen consumption, CO = cardiac output, CAO2 = oxygen concentration of arterial blood and CVO2 = oxygen concentration of venous blood. Thus, CO = VO2/CAO2– CVO2, CO = 500/0.24–0.16, CO = 500/0.8, CO = 6.25 l/min. Cardiac output is also given by product of stroke volume and heart rate. Thus, stroke volume = cardiac output / heart rate = 6.25/70 × 1000 stroke volume = 90 ml approximately.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 165
Correct
-
Which of these is secreted by both macrophages and muscle cells?
Your Answer: Interleukin-6
Explanation:IL-6 is secreted by the T cells and macrophages and is a pro inflammatory cytokine. It is secreted in response to trauma e.g. burns and tissue damage that leads to inflammation. Apart from this its is also a myokine and is elevated due to muscle contraction. Other functions include: stimulate osteoclast formation when secreted by osteoblasts, mediate fever in acute phase response and are responsible for energy metabolism in muscle and fatty tissues. Inhibitors of IL-6 e.g. oestrogen are used as a treatment for postmenopausal osteoporosis.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 166
Incorrect
-
From which branchial (pharyngeal) pouch does the inferior parathyroid gland arise?
Your Answer: 4th
Correct Answer: 3rd
Explanation:The following structures arise from each branchial pouch:
1st pouch – eustachian tube, middle ear, mastoid, and inner layer of the tympanic membrane
2nd pouch – middle ear, palatine tonsils
3rd pouch – inferior parathyroid glands, thymus
4th pouch – superior parathyroid glands, ultimobranchial body which forms the parafollicular C-cells of the thyroid gland, musculature and cartilage of larynx (along with the sixth pharyngeal pouch)
5th pouch – rudimentary structure
6th pouch – along with the fourth pouch, contributes to the formation of the musculature and cartilage of the larynx.
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This question is part of the following fields:
- Anatomy
- Endocrine; Embryology
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Question 167
Incorrect
-
Which of the following is the source of blood supply to the artery of the round ligament at the head of the femur?
Your Answer: Lateral femoral circumflex artery
Correct Answer: Obturator artery
Explanation:The posterior branch of the obturator artery provides an articular branch to the head of the femur.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 168
Incorrect
-
A biopsy taken from the respiratory passage of a 37 year old male, chronic smoker will mostly likely show which cellular adaptation?
Your Answer: Mucous hyperplasia
Correct Answer: Stratified squamous metaplasia
Explanation:Metaplasia is a change in the cell type caused in part due to an extrinsic stress on the organ. It involves a change in the surface epithelium from one cell type to the another, most commonly squamous to columnar. This is a reversible process, and removal of the stress should theoretically reverse the surface epithelium back to normal morphology. Respiratory tract metaplasia is a classic example, in which the normal pseudostratified columnar epithelium is replaced by stratified squamous epithelium to better cope with the stress. Under continuous stress metaplasia can progress to dysplasia which is a disordered growth of cells eventually leading to the development of carcinoma.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Respiratory
- Pathology
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Question 169
Correct
-
The Brunner glands secrete an alkaline product that helps maintain an optimal pH for pancreatic enzyme activity. Where are these glands located?
Your Answer: Submucosa of the duodeneum
Explanation:The Brunner glands are located in the submucosa of the duodenum. These glands are connected to the interstitial lumen by ducts that open into certain crypts. They secrete an alkaline product that protects the duodenal mucosa from the acidic chyme and helps achieve an optimal pH for the enzymes.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 170
Incorrect
-
The following organs would be expected to lie within the right lower quadrant of the abdomen, assuming that the gastrointestinal tract is rotated normally:
Your Answer: Stomach, duodenum, spleen, pancreas and liver
Correct Answer: Distal jejunum, caecum, vermiform appendix
Explanation:The abdomen is divided by theoretical anatomic lines into four quadrants. The median plane follows the linea alba and extends from the xiphoid process to the pubic symphysis and splits the abdomen in half. The transumbilical plane is a horizontal line that runs at the level of the umbilicus. This forms the upper right and left quadrants and the lower right and left quadrants. Structures in the right lower quadrant include: caecum, appendix, part of the small intestine, ascending colon, the right half of the female reproductive system, right ureter. Pain in this region is most commonly associated with appendicitis.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 171
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.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 172
Correct
-
The presence of oval fat bodies in the urine is most likely to be seen in which of the following conditions?
Your Answer: Nephrotic syndrome
Explanation:Nephrotic syndrome is associated with the presence of oval fat bodies on urinalysis due to increased proteinuria and lipiduria.
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This question is part of the following fields:
- Pathology
- Renal
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Question 173
Correct
-
During a radical mastectomy for advanced breast cancer, the surgeon injured the long thoracic nerve. Which among the following muscles is likely to be affected?
Your Answer: Serratus anterior
Explanation:The long thoracic nerve innervates the serratus anterior muscle which holds the scapula forward and balances the rhomboids and the trapezius muscles which retract the scapula. Injury to this nerve results in a ‘winged scapula’ with a posterior protrusion.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 174
Correct
-
What is the innervation of the laryngeal mucosa inferior to the true vocal cord?
Your Answer: Recurrent laryngeal nerve
Explanation:Motor innervation to all other muscles of the larynx and sensory innervation to the subglottis is by the recurrent laryngeal nerve.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 175
Incorrect
-
A 40 year old man from Japan was diagnosed with cancer of the oesophagus. He is to undergo esophagectomy. While mobilizing the oesophagus in the neck, for resection and anastomosis with the stomach tube on the left side, the surgeon must be cautious not to injure a vital structure. Which of the following is it?
Your Answer: Azygos vein
Correct Answer: Thoracic duct
Explanation:The oesophagus is divided into 3 portions: cervical (part that is in the neck), thoracic portion and the abdominal portion. The cervical part is bordered by the trachea anteriorly and the prevertebral fascia covering the bodies of the 6,7 and 8th vertebra posteriorly. The thoracic duct lies on the left side at the level of the sixth cervical vertebra. The carotid sheath with its contents and lower poles of the lateral lobes of thyroid gland are lateral. The thoracic duct is the structure most likely to be injured.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 176
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: MCV = haemoglobin concentration/haematocrit
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.
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This question is part of the following fields:
- General
- Physiology
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Question 177
Correct
-
Which of the following is a landmark to identify the site of the 2nd costal cartilage?
Your Answer: Sternal angle
Explanation:The sternal angle is an important part where the second costal cartilage attaches to the sternum. Finding the sternal angle will help in finding the second costal cartilage and intercostal space.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 178
Correct
-
A 20-year old cyclist falls off a speeding bike and fractures a structure that articulates with the tubercle of the 7th rib. Which structure is fractured?
Your Answer: Transverse process of vertebra T7
Explanation:A rib tubercle is a projection that is postero-inferior and lateral to the neck of a rib which articulates with the transverse process of the corresponding vertebra i.e. of the same number. Therefore, the tubercle of rib 7 articulates with the transverse process of T7 vertebra. The head of the rib 7, on the other hand, articulates with the 6th vertebra superiorly and the 7th vertebra inferiorly.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 179
Correct
-
Which of the following organs is most likely to have dendritic cells?
Your Answer: Skin
Explanation:Dendritic cells are part of the immune system and they function mainly as antigen presenting cells. They are present in small quantities in tissues which are in contact in the external environment. Mainly in the skin and to a lesser extent in the lining of the nose, lungs, stomach and intestines. In the skin they are known as Langerhans cells.
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This question is part of the following fields:
- General
- Physiology
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Question 180
Incorrect
-
From which source does the lingual artery originate?
Your Answer: Sphenopalatine
Correct Answer: External carotid
Explanation:The lingual artery arises from the external carotid between the superior thyroid artery and facial artery. It can be located easily on the lower surface of the tongue. The terminal branch of the lingual artery is the deep lingual artery. On its course the lingual artery gives off side branches: dorsal lingual branches that supply the dorsum of the tongue till the epiglottis; sublingual artery that supplies the sublingual gland.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 181
Correct
-
A 45 -year-old female is recently diagnosed with breast cancer. She has a 8-cm-diameter mass in her left breast, with enlarged left axillary node. What is the most likely stage of her disease?
Your Answer: IIIA
Explanation:Stage IIIA breast cancer is T0–2 N2 M0 or T3 N1-2 M0 disease. It describes invasive breast cancer in which either: the tumour is smaller than 5 cm in diameter and has spread to 4 to 9 axillary lymph nodes; or it is found through imaging studies or clinical exam to have spread to internal mammary nodes (near the breastbone found during imaging tests or a physical exam); or the tumour is larger than 5 cm and has spread to 1 to 9 axillary nodes, or to internal mammary nodes. In this stage, the cancer has not metastasized (spread to distant sites).
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 182
Incorrect
-
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: Hypotension
Correct 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 183
Correct
-
What is the nerve supply of the muscle that is inserted onto the crest of the lesser tubercle of the humerus?
Your Answer: Lower subscapular
Explanation:The muscle is the subscapularis muscle which is supplied by the lower subscapular nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 184
Incorrect
-
An explorative laparotomy is done on a 23 year old following a gunshot abdominal injury through the right iliac fossa. It is found that the ileocolic artery is severed and the bullet had perforated the caecum. From which branch does the ileocolic artery originate?
Your Answer: Inferior mesenteric artery
Correct Answer: Superior mesenteric artery
Explanation:Ileocolic artery branches off from the superior mesenteric artery. It then divides to give a superior and inferior branch.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 185
Correct
-
The bronchial circulation is a part of the circulatory system that supplies nutrients and oxygen to the pulmonary parenchyma. What percentage of cardiac output is received by bronchial circulation?
Your Answer: 2%
Explanation:The bronchial circulation is part of the systemic circulation and receives about 2% of the cardiac output from the left heart. Bronchial arteries arise from branches of the aorta, intercostal, subclavian or internal mammary arteries. The bronchial arteries supply the tracheobronchial tree with both nutrients and O2. It is complementary to the pulmonary circulation that brings deoxygenated blood to the lungs and carries oxygenated blood away from them in order to oxygenate the rest of the body.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 186
Correct
-
A 25 year-old female medical student presents with fever, lack of appetite, rashes, sore throat and lymphadenopathy. Peripheral smear shows atypical lymphocytes. Which is the most likely organism responsible for this patient's condition?
Your Answer: Epstein–Barr virus
Explanation:Epstein-Barr virus is in the herpes family of viruses and most people will become infected with EBV sometime during their lives. EBV commonly causes infectious mononucleosis, or mono, a contagious viral illness that initially attacks the lymph nodes in the neck and throat. When these tissues become less effective in fighting infection, sore throats, swelling of the nodes and fever may result.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 187
Correct
-
A 25 year old women is pregnant with her second child. She is A- blood group. Her first child was Rh+ and the father is also Rh+. The second child is at a risk of developing which condition?
Your Answer: Haemolytic disease of the new-born
Explanation:This infant is at risk for haemolytic disease of the new born also known as erythroblastosis fetalis. In the pregnancy, Rh-positive RBC’s cross the placenta and enter the mothers blood system. She then becomes sensitised and forms IgG antibodies/anti-Rh antibodies against them. The second child is at a greater risk for this disease than the first child with Rh-positive blood group as during the second pregnancy, a more powerful response is produced. IgG has the ability to cross the placenta and bind to the fetal RBCs (type II hypersensitivity reaction) which are phagocytosed by the macrophages.
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This question is part of the following fields:
- Inflammation & Immunology; Haematology
- Pathology
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Question 188
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.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 189
Correct
-
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: 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.
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This question is part of the following fields:
- Physiology
- Renal
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Question 190
Correct
-
What is the most likely cause of prolonged bleeding time in a 40 year old women admitted for a laparoscopic cholecystectomy?
Your 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 191
Incorrect
-
In which of the following compartments of the femoral sheath is the femoral artery located?
Your Answer: Medial compartment
Correct Answer: Lateral compartment
Explanation:The femoral sheath also known as the crural sheath is made up of three compartments; lateral, intermediate and the medial. The femoral artery is contained in the lateral compartment of the femoral sheath while the femoral vein is in the intermediate compartment.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 192
Incorrect
-
A 45 year old man who complains of chronic post prandial, burning epigastric pain undergoes a gastrointestinal endoscopy. There is no apparent mass or haemorrhage and a biopsy is taken from the lower oesophageal mucosa just above the gastro-oesophageal junction. The results reveal the presence of columnar cells interspersed with goblet cells. Which change best explains the above mentioned histology?
Your Answer: Hyperplasia
Correct Answer: Metaplasia
Explanation:Metaplasia is the transformation of one type of epithelium into another as a means to better cope with external stress on that epithelium. In this case metaplasia occurs due to the inflammation resulting from gastro-oesophageal reflux disease. Dysplasia is disordered cellular growth. Hyperplasia is an increase in cell number but not cell type i.e. transformation. Carcinoma is characterized by cellular atypia. Ischaemia would result in necrosis with ulceration. Carcinoma insitu involves dysplastic atypical cells with the basement membrane intact and atrophy would mean a decrease in number of cells.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Gastrointestinal
- Pathology
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Question 193
Correct
-
Signals pass through neuromuscular junctions via the neurotransmitter acetylcholine. After release from the skeletal neuromuscular junction, acetylcholine:
Your Answer: Causes postsynaptic depolarisation
Explanation:Acetylcholine is released from the presynaptic membrane into the cleft where it binds to the ion gated channels on the post synaptic membrane, causing them to open. This results in sodium entering into the fibre and further depolarizing it, creating an action potential.
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This question is part of the following fields:
- General
- Physiology
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Question 194
Incorrect
-
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: Decreased production of erythropoietin
Correct 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.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 195
Correct
-
A 60-year old woman who has a left sided post-pneumonic effusion, was to have some pleural fluid aspirated for culture and sensitivity. If the medical intern in charge of the procedure decided to aspirate while the patient is sitting up on her bed, where in the pleural cavity would the fluid tend to accumulate?
Your Answer: Costodiaphragmatic recess
Explanation:The lowest part of the pleural cavity is the costodiaphragmatic recess and it the space in which the pleural fluid will accumulate when the patient sits up.
The cupola is part of the pleural cavity that extends into the root of the neck above the first rib.
The costomediastinal recess is the junction at which the costal pleura becomes the mediastinal pleura.
The middle mediastinum is the part of the mediastinum that is occupied by the heart.
The hilar reflection is the point where the mediastinal pleura is reflected to continue on as the visceral pleura.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 196
Correct
-
A 55- year old male patient with cancer of the head of the pancreas was to undergo whipple's operation to have the tumour removed. During the surgery, the surgeon had to ligate the inferior pancreaticoduodenal artery to stop blood supply to the head of the pancreas. Which of the following arteries does the inferior pancreaticoduodenal artery branch from?
Your Answer: Superior mesenteric artery
Explanation:The inferior pancreaticoduodenal artery is a branch of the superior mesenteric artery or from the first intestinal branch of the superior mesenteric artery. Once given off, it runs to the right between the pancreatic head and the duodenum and then ascends to form an anastomosis with the superior pancreaticoduodenal artery.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 197
Correct
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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 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.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 198
Correct
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A 13-year-old girl has complained of pain in her left arm for 4 months. An X-ray reveals a mass along with erosion of the affected humerus. Histologically, the tumour is found to be formed by small, round, blue cells. What is the most likely diagnosis?
Your Answer: Ewing’s sarcoma
Explanation:Ewing’s sarcoma is formed by small, round, blue cells, and is common in children. The usually develop in limbs, and clinical findings include pain and inflammation, with lytic destruction showing up on X-rays.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 199
Correct
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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.
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This question is part of the following fields:
- Anatomy
- Head & Neck; Neurology
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Question 200
Incorrect
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An excision of a mass in the right parietal area of the head will be performed. In which layer of the scalp are the nerves and blood vessels located?
Your Answer: Aponeurosis
Correct Answer: Connective tissue
Explanation:The scalp is the anatomical area bordered by the face at the front, and by the neck at the sides and back. The scalp is usually described as having five layers:
1. The skin which contains numerous sebaceous glands and hair follicles.
2. The connective tissue, a dense subcutaneous layer of fat and fibrous tissue that lies beneath the skin, containing the nerves and vessels of the scalp.
3. The aponeurosis or galea aponeurotica, a tough layer of dense fibrous tissue which runs from the frontalis muscle anteriorly to the occipitalis posteriorly.
4. The loose areolar connective tissue layer provides an easy plane of separation between the upper three layers and the pericranium.
5. The pericranium is the periosteum of the skull bones and provides nutrition to the bone and the capacity for repair.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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