-
Question 1
Incorrect
-
Regarding the cardiac muscle striations as viewed under the microscope, which areas are dark?
Your Answer: H band and m line
Correct Answer: A band and z line
Explanation:Dark bands: a, h. Dark line: z. Clear band: i, m
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 2
Correct
-
The process whereby bacterial products interact with plasma factors and cells to produce agents that attract neutrophils to an infected area is called:
Your Answer: Chemotaxis
Explanation:During an inflammatory process many cytokines are produced that act as chemokines to attract neutrophils to the site of inflammation. These include bacterial products, IL-8, C5a and LTB4.
-
This question is part of the following fields:
- Immunology
- Medicine
-
-
Question 3
Incorrect
-
The effects of β1 stimulation include the following
Your Answer: Dephosphorylation of phospholambin
Correct Answer: Increased strength of contraction
Explanation:β1 stimulation include the phosphorylation of L type Ca++ channels and phospholamban and increased Ca++ influx from myocytes.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 4
Correct
-
Currents caused by opening of which of the following channels contribute to the repolarization phase of the action potential of the ventricular muscle fibers?
Your Answer: Potassium channels
Explanation:Depolarization occurs due to opening of the voltage gated sodium channels. Repolarization occurs due to opening of the voltage gates potassium channels causing an out flux of potassium ions, decreasing the membrane potential towards resting potential.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 5
Incorrect
-
Calcium is transported over the brush border in the gut, via which transporter / channel?
Your Answer: Ca2+ dependant ATPase
Correct Answer: TRPV 6
Explanation:Transient Receptor Potential Vanilloid 6 or TRPV 6 is a calcium channel located in the cell membrane which is present in a variety of organs, including small intestine, oesophagus, stomach, colon, placenta, kidney, and uterus. In the intestine, it is located in the apical brush-border membrane of the enterocyte, regulating the entry of calcium into the cell.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 6
Correct
-
Selectins
Your Answer: Interact with carbohydrate ligands or mucin complexes on leucocytes and endothelial cells
Explanation:Selectins are involved in constitutive lymphocyte homing, and in chronic and acute inflammation processes, including post-ischemic inflammation. Each selectin has a carbohydrate recognition domain that mediates binding to specific glycans on apposing cells.
-
This question is part of the following fields:
- Cell Biology
- Medicine
-
-
Question 7
Correct
-
Portal vein receives its blood from all the following except:
Your Answer: Kidney
Explanation:The portal vein receives blood from the intestines via the superior and inferior mesenteric veins, from stomach via the gastric veins and from the spleen and pancreas via splenic vein. The kidney is supplied by the renal artery and drains into the renal vein into the inferior venacava.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 8
Correct
-
ADH causes?
Your Answer: Increased permeability of the collecting ducts to water
Explanation:Vasopressin (ADH) has three main effects:1. Increasing the water permeability of distal convoluted tubule and collecting duct cells in the kidney, thus allowing water reabsorption and excretion of more concentrated urine.2. Increasing permeability of the inner medullary portion of the collecting duct to urea by regulating the cell surface expression of urea transporters.3. Acute increase of sodium absorption across the ascending loop of Henle.
-
This question is part of the following fields:
- Medicine
- Renal
-
-
Question 9
Correct
-
Which of the following happens when anterograde neurons are stimulated?
Your Answer: Smooth muscle relaxation ahead of the stimulus
Explanation:Nitric oxide is thought to act as an anterograde neurotransmitter. Nitric oxide causes relaxation of smooth muscles ahead of the stimulus. Clinically it is used as a potent vasodilator.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 10
Incorrect
-
Which of the following associations is false?
Your Answer: Facial nerve – stylomastoid foramen
Correct Answer: Mandibular nerve – foramen lacerum
Explanation:– The olfactory nerves pass through the cribriform plate- The maxillary division of the trigeminal nerve passes through the foramen rotundum- The facial nerve passes through the stylomastoid foramen- The mandibular division of the trigeminal nerve pass through the foramen ovale- The glossopharyngeal nerve passes through the jugular foramen.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 11
Correct
-
A 28 year old female presents to the rheumatology clinic for review. She has a history of adult onset Still's disease and complains of joint pains and persistent skin rash despite undergoing treatment with methotrexate and etanercept. On examination, an erythematous macular rash and active synovitis is noted. CRP is high (95 mg/dl). Which of the following interventions would be most appropriate?
Your Answer: Anakinra
Explanation:Adult onset Still’s disease (AOSD) is an uncommon systemic inflammatory disease on the clinical spectrum of autoinflammatory disorders. Its presentation and clinical course may result in several well-differentiated phenotypes: from a systemic and highly symptomatic pattern to a chronic articular pattern. Overproduction of numerous pro-inflammatory cytokines is observed in AOSD. Anakinra, a human interleukin (IL)-1R antagonist, has recently been approved in the treatment of AOSD. Denosumab is a RANK ligand inhibitor used in the treatment of osteoporosis. Mepolizumab is used in the treatment of severe asthma with elevated eosinophils. There is some evidence to support the use of tocilizumab, an anti-IL6 monoclonal antibody in adult onset Still’s, but there is stronger data favouring the use of tocilizumab in the treatment of rheumatoid arthritis. Rituximab is usually reserved for patients who are unresponsive to anakinra.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 12
Incorrect
-
A case-control study is being designed to look at the relationship between eczema and a new vaccine for yellow fever. What is the usual outcome measure in a case-control study?
Your Answer: Numbers needed to harm
Correct Answer: Odds ratio
Explanation:A case–control study (also known as case–referent study) is a type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute. Case–control studies are often used to identify factors that may contribute to a medical condition by comparing subjects who have that condition/disease (the cases) with patients who do not have the condition/disease but are otherwise similar (the controls).An odds ratio (OR) is a statistic that quantifies the strength of the association between two events, A and B. The odds ratio is defined as the ratio of the odds of A in the presence of B and the odds of A in the absence of B or vice versa.
-
This question is part of the following fields:
- Medicine
- Research Skills
-
-
Question 13
Correct
-
A 50-year-old farmer, under treatment for depression, presents to the emergency department following an intentional overdose of an unidentified substance. On examination, he was found to be bradycardic, hypotensive, hyper-salivating, and disoriented. On ocular examination, his pupils were found to be miotic. What is the most likely substance he ingested?
Your Answer: An organophosphate insecticide
Explanation:The farmer has most likely ingested an organophosphate insecticide.Organophosphorus compounds are used widely as:• Insecticides – Malathion, parathion, diazinon, dichlorvos• Nerve gases – Soman, sarin, tabun, VX• Ophthalmic agents – Echothiophate• Antihelmintics – Trichlorfon• Herbicides – merphos• Industrial chemical (plasticizer) – Tricresyl phosphateSigns and symptoms of Organophosphorus Poisoning (OPP) can be classified as:• Muscarinic effects:o Cardiovascular – Bradycardia, hypotensiono Respiratory – Rhinorrhoea, bronchorrhea, bronchospasm, cough, severe respiratory distresso Gastrointestinal – Hypersalivation, nausea and vomiting, abdominal pain, diarrhoea, faecal incontinenceo Genitourinary – Incontinenceo Ocular – Blurred vision, miosiso Glands – Increased lacrimation, diaphoresis• Nicotinic effects:o Muscle fasciculation, weakness, cramping, diaphragmatic failure, and autonomic side effects include: hypertension, tachycardia, and mydriasis.• Central nervous system (CNS) effects:o Anxiety, emotional lability, restlessness, confusion, ataxia, tremors, seizures, coma, apnoeaMainstay Treatment:• Decontamination• Securing Airway, Breathing and Circulation• Atropine• Pralidoxime• Benzodiazepines
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 14
Incorrect
-
In which cell would you find a Nissl body?
Your Answer: Schwann cell
Correct Answer: Bipolar neuron
Explanation:Nissl bodies are the structures of protein synthesis in neurones. They are granular bodies of Rough Endoplasmic Reticulum and ribosomes. Astrocytes, Microglia, Schwann cell, oligodendrocytes are collectively known as glia or supporting cells of the nervous system.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 15
Incorrect
-
An 87-year-old woman had to double up her dosage of morphine 60mg into 120mg twice a day, in addition to another 10mg oral Morphine 6 times a day. What is the best method of management?
Your Answer: 90mg MR morphine plus 30mg every 4 hours
Correct Answer: Subcutaneous morphine infusion
Explanation:Stable dose of Morphine is essential for chronic cases of pain that are non-malignant in origin. Using the SC route avoids having to intravenously cannulate a patient and allows for a continuous infusion of drugs over a calculated period of time providing constant dosing A significant advantage is that plasma levels of a drug are much more stable, and appropriate symptom control can be achieved without the toxic effects of the peaks and troughs resulting from episodic drug administration.
-
This question is part of the following fields:
- Geriatrics
- Medicine
-
-
Question 16
Incorrect
-
The transport of the di- and tri-peptides into enterocytes is by:
Your Answer: H+ dependent peptide transporter 2
Correct Answer: H+ dependent peptide transporter 1
Explanation:Peptides longer that four amino acids are not absorbed. There is abundant absorption of di and tri peptidases in the small intestine. They are absorbed into the epithelial cell of the small intestine via a transporter called Peptide Transporter 1 by co transport with H+ ions.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 17
Incorrect
-
After eating a meal containing a moderate amount of fat, which percentage of fat is likely to be absorbed from the GIT in an adult?
Your Answer: 75%
Correct Answer: 95%
Explanation:About 95% of dietary fat is absorbed.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 18
Correct
-
What is the blood supply to the liver?
Your Answer: Hepatic artery and hepatic portal vein
Explanation:The liver receives a dual blood supply from the hepatic portal vein and hepatic arteries. The hepatic portal vein delivers approximately 75% of the liver’s blood supply, and carries venous blood drained from the spleen, gastrointestinal tract, and its associated organs. The hepatic arteries supply arterial blood to the liver, accounting for the remaining quarter of its blood flow. Oxygen is provided from both sources; approximately half of the liver’s oxygen demand is met by the hepatic portal vein, and half is met by the hepatic arteries
-
This question is part of the following fields:
- Hepatobiliary
- Medicine
-
-
Question 19
Correct
-
The infoldings or spaces between the bases of the villi are known as
Your Answer: Crypts of Lieberkühn
Explanation:An intestinal gland (also crypt of Lieberkühn and intestinal crypt) is a gland found in the intestinal epithelium lining of the small intestine and large intestine (colon) between the villi.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 20
Correct
-
Which of the following features is least commonly seen in Gitelman’s syndrome?
Your Answer: Hypertension
Explanation:Gitelman syndrome is an autosomal recessive kidney disorder characterized by hypokalaemia metabolic alkalosis with hypocalciuria, and hypomagnesemia. In contrast to patients with Gordon’s syndrome, those suffering from Gitelman’s syndrome are generally normotensive or hypotensive.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 21
Incorrect
-
The midbrain, medulla and pons, contain the following cranial nerve nuclei?
Your Answer: CN 5 – 12
Correct Answer: CN 3 - 12
Explanation:The cranial nerves (with the exception of I and II) originate in the brainstem, which includes the midbrain, the pons, and the medulla.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 22
Incorrect
-
Regarding CSF:
Your Answer: Its volume is about 150ml – 500ml
Correct Answer: Disruption of arachnoid villi function results in a communicating hydrocephalus
Explanation:In normal adults CSF volume is around 125ml to 150ml. Turnover of the entire volume of cerebrospinal fluid is about 3 to 4 times a day. Composition of CSF is similar to that of plasma except that CSF is nearly protein-free compared with plasma and has different electrolyte levels. Blockage of the foramina causes an obstructive or non-communicating hydrocephalus. Communicating hydrocephalus or non-obstructive hydrocephalus is caused by impaired CSF reabsorption in the absence of any CSF flow obstruction.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 23
Correct
-
The following can cause steatorrhea except
Your Answer: Diseases that destroy the endocrine portion of the pancreas
Explanation:Dietary fats and lipids are usually efficiently digested and over 90% absorbed. Impaired digestion or absorption can result in fatty stools. Possible causes include exocrine (not endocrine) pancreatic insufficiency, with poor digestion from lack of lipases, loss of bile salts, which reduces micelle formation, and small intestinal disease producing malabsorption. Various other causes including certain medicines that block fat absorption, or indigestible or excess oil/fat in diet.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 24
Correct
-
In the Fick‘s method of measuring cardiac output, the arterial oxygen content can be measured in a sample obtained from
Your Answer: The pulmonary vein
Explanation:In Fick’s original method, the following variables are measured:VO2, oxygen consumption in ml of pure gaseous oxygen per minute. This may be measured using a spirometer within a closed rebreathing circuit incorporating a CO2 absorberCa, the oxygen concentration of blood taken from the pulmonary vein (representing oxygenated blood)Cv, the oxygen concentration of blood from an intravenous cannula (representing deoxygenated blood)From these values, we know that:VO2 = (CO x Ca) – (CO x Cv)where CO = Cardiac Output, Ca = Oxygen concentration of arterial blood and Cv = Oxygen concentration of mixed venous blood.This allows us to sayCO = VO2/{Ca – Cv}and hence calculate cardiac output.Note that (Ca – Cv) is also known as the arteriovenous oxygen difference.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 25
Incorrect
-
Growth hormone deficiency causes?
Your Answer: Protein anabolism
Correct Answer: Decreased epiphyseal growth
Explanation:Growth hormone deficiency is caused by conditions affecting the pituitary gland, such as tumours. Its effects depend on the age of the patient: in infancy and childhood, growth failure is most likely to occur. The epiphyseal plate is the area in long bones where growth occurs, and it is the area affected by growth hormone deficiency. Poor growth/shortness is the main symptom of GH deficiency in children, usually resulting in growth at about half the usual rate for age.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 26
Correct
-
Regarding cardiac muscle contractility, the afterload refers to:
Your Answer: The resistance against which blood is expected
Explanation:The afterload for the left ventricle is the aortic pressure. Hence it is this pressure that offers resistance against which the blood is to be expelled from the heart.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 27
Correct
-
A 55 year old female presents with progressive dyspnoea, dry cough and fever. She started methotrexate therapy six weeks ago. The current regimen includes methotrexate 15 mg/ week, folic acid 5 mg/day and aspirin 75 mg/day. There is no history of any other chronic illness. Vitals are as follows: Temp: 37.8C, pulse: 100 beats/min, BP: 110/80mmHg and SaO2: 90% on air. Examination reveals synovitis in both wrists, and metacarpophalangeal joints. On auscultation, there are scattered crepitations. Blood test reports are given below:Haemoglobin: 13.1g/dl (13.0 – 18.0 g/dL)WBC: 8.2 x109/l (4 – 11 x 109/l)Neutrophils: 5.1×109/l (1.5 – 7 x 109/l)Platelets: 280 x109/l (150 – 400 x 109/L)ESR: 48 mm/hr (0 – 30 mm/1st hr)Urea, electrolytes and creatinine: normalCXR: patchy airspace shadows bilaterallyWhat is the most likely diagnosis?
Your Answer: Methotrexate pneumonitis
Explanation:Pneumonitis is a serious and unpredictable side-effect of treatment with methotrexate (MTX) that may become life-threatening. The typical clinical symptoms include progressive shortness of breath and cough, often associated with fever. Hypoxaemia and tachypnoea are always present and crackles are frequently audible. Chest radiography reveals a diffuse interstitial or mixed interstitial and alveolar infiltrate, with a predilection for the lower lung fields. Pulmonary function tests show a restrictive pattern with diminished diffusion capacity. Lung biopsy reveals cellular interstitial infiltrates, granulomas or a diffuse alveolar damage pattern accompanied by perivascular inflammation. Most patients present in the first few months of starting methotrexate. It is important that all patients receiving methotrexate be educated concerning this potential adverse reaction and instructed to contact their physicians should significant new pulmonary symptoms develop while undergoing therapy. If methotrexate pneumonitis is suspected, methotrexate should be discontinued, supportive measures instituted and careful examination for different causes of respiratory distress conducted. This may be treated with corticosteroids once underlying infection has been excluded.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 28
Correct
-
Question 29
Correct
-
Which of the following tracts are involved in the control of vital functions?
Your Answer: Reticulospinal
Explanation:Reticulospinal tract pass down from the reticular formation of the mid brain, pons and medulla. It descends in the lateral white column. Both sets of fibers enter the anterior grey column and may facilitate or inhibit the gamma and alpha neurons. By this means the reticulospinal tract controls voluntary and reflex activities. It also contains the descending autonomic fiber, thus providing a pathway for the hypothalamus to control the sympathetic and parasympathetic pathways.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 30
Incorrect
-
What is the main reason for checking the urea and electrolytes prior to commencing a patient on amiodarone?
Your Answer: To detect impaired renal function
Correct Answer: To detect hypokalaemia
Explanation:All antiarrhythmic drugs have the potential to cause arrhythmias. Coexistent hypokalaemia significantly increases this risk.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 31
Correct
-
With regards to the Na+/K+ ATPase, which one of the following is correct?
Your Answer: 3 Na+ released into the extracellular fluid
Explanation:Na+/K+ pump or sodium–potassium pump is an enzyme found in the plasma membrane. This pumping is active (i.e. it uses energy from ATP) and is important for cell physiology. Its simple function is to pump 3 sodium ions out for every 2 potassium ions taken in and since they both have equal ionic charges, this creates a electrochemical gradient between a cell and its exterior.
-
This question is part of the following fields:
- Cell Biology
- Medicine
-
-
Question 32
Correct
-
A 68 year old man presents with acute symptoms of gout on his first metatarsophalangeal joint. Which option best explains the underlying mechanism of gout?
Your Answer: Decreased renal excretion of uric acid
Explanation:Primary gout is related more often to underexcretion of uric acid or overproduction.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 33
Correct
-
The following play a role in regulation of intestinal iron absorption except:
Your Answer: Urinary iron excretion rate
Explanation:The human body’s rate of iron absorption appears to respond to a variety of interdependent factors, including total iron stores, dietary intake, the extent to which the bone marrow is producing new red blood cells, the concentration of haemoglobin in the blood, and the oxygen content of the blood. Classic examples of genetic iron overload includes hereditary hemochromatosis (HH) and the more severe disease juvenile hemochromatosis (JH).
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 34
Incorrect
-
A 35-year-old man was brought to the ER with acute confusion. He's a known case of bipolar disorder under treatment with mood stabilizers. Blood investigations revealed lithium toxicity. A decision is made to start the patient on sodium bicarbonate. What is the rationale behind the use of sodium bicarbonate in this patient?
Your Answer: Reduce gastrointestinal tract absorption
Correct Answer: Increases urine alkalinity
Explanation:The rationale behind the use of sodium bicarbonate is that it increases the alkalinity of the urine promoting lithium excretion. The preferred treatment in severe cases would be haemodialysis.Lithium is a mood-stabilizing drug used most commonly prophylactically in bipolar disorder but also as an adjunct in refractory depression. It has a very narrow therapeutic range (0.4-1.0 mmol/L) and a long plasma half-life being excreted primarily by the kidneys. Lithium toxicity generally occurs following concentrations > 1.5 mmol/L.Toxicity may be precipitated by dehydration, renal failure, diuretics (especially Bendroflumethiazide), ACE inhibitors, NSAIDs and metronidazole.Features of toxicityCoarse tremor (a fine tremor is seen in therapeutic levels)HyperreflexiaAcute confusionSeizureComaManagementMild-moderate toxicity may respond to volume resuscitation with normal salineHaemodialysis may be needed in severe toxicitySodium bicarbonate is sometimes used but there is limited evidence to support this. By increasing the alkalinity of the urine it promotes lithium excretion.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 35
Incorrect
-
The following is true in relation to coronary venous drainage?
Your Answer: Small veins in left side drains into left atrium directly
Correct Answer: Most venous return ultimately drains into right atrium via the coronary sinus
Explanation:Most of the venous blood returns to the heart via the coronary sinus and the anterior cardiac veins. Apart from these there are other vessels that drain directly into the heart chambers
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 36
Incorrect
-
Which factors increase the end-diastolic volume?
Your Answer: Standing
Correct Answer: Constriction of veins
Explanation:End diastolic volume is also known as preload. It is the amount of blood the heart contracts against. Constriction of veins will decrease venous pooling and increase venous return, hence increasing the end diastolic volume. Standing will increase venous pooling hence decreasing venous return and end diastolic volume. Raised intrapericardial pressure will also decrease venous return and hence end diastolic volume.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 37
Incorrect
-
Around 30 patients have been admitted to the hospital following a suspected chemical attack in the city. The patients are extremely unwell, with symptoms of excessive salivation, lacrimation, diarrhoea, and emesis. Sarin gas was suspected as the most likely agent used in the attack. What is the mechanism of action of this chemical agent?
Your Answer: Anti-cholinergic
Correct Answer: Inhibition of acetylcholinesterase
Explanation:Sarin acts by inhibiting acetylcholinesterase.Sarin gas is a highly toxic synthetic organophosphorus compound which causes inhibition of the enzyme acetylcholinesteraseSarin gas is a highly toxic synthetic organophosphorus compound which causes inhibition of the enzyme acetylcholinesterase. This results in high levels of acetylcholine (ACh).The effects of excessive ACh can be remembered by the mnemonic DUMBELLS:DiarrhoeaUrinationMiosis/muscle weaknessBronchorrhea/BradycardiaEmesisLacrimationSalivation/sweatingOrganophosphate insecticide poisoning:One of the effects of organophosphate poisoning is inhibition of acetylcholinesteraseFeatures can be predicted by the accumulation of acetylcholine (mnemonic = SLUD)SalivationLacrimationUrinationDefecation/diarrhoeacardiovascular: hypotension, bradycardiamiosis, muscle fasciculation.Organophosphate poisoning is treated with the anti-muscarinic atropine.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 38
Correct
-
Select one true statement about haemoglobin synthesis…
Your Answer: Occurs in the cytosol of developing red cells.
Explanation:Haemoglobin (Hb) is synthesized in a complex series of steps. The haem part is synthesized in a series of steps in the mitochondria and the cytosol of immature red blood cells, while the globin protein parts are synthesized by ribosomes in the cytosol. Production of Hb continues in the cell throughout its early development from the proerythroblast to the reticulocyte in the bone marrow.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 39
Incorrect
-
Endotoxin will typically act on which one of the following cells, to produce endogenous pyrogens?
Your Answer: Neutrophils
Correct Answer: Monocytes
Explanation:Endotoxin, also known as lipopolysaccharides or lipoglycans, are molecules that consist of a lipid and a polysaccharide. They bind to many cell types, but especially to monocytes, promoting the secretion of proinflammatory cytokines, acting as a pyrogen.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 40
Incorrect
-
Select the correct statement regarding the macro anatomy of the thyroid gland.
Your Answer: It can have only two lobes.
Correct Answer: It surrounds the trachea at the front of the neck.
Explanation:The thyroid is located around the trachea, in the anterior portion of the neck. It is formed by two lobes which are connected by an isthmus. The presence of a pyramidal lobe, or third lobe, is considered to be a normal anatomical variant. It originates from the primitive pharynx and the neural crest and has a rich vascular supply.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 41
Correct
-
Where do the portal hypophysial vessels arise?
Your Answer: Median eminence
Explanation:The hypothalamic-hypophysial portal system connects the brain to the anterior pituitary. It is made up of two capillary beds, one in the median eminence and the other in the anterior pituitary. Blood from the plexus of the median eminence is carried by portal veins, draining into the cavernous and posterior intercavernous sinuses. This system delivers hypothalamic hormones to their target cells.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 42
Incorrect
-
Which of the following intercellular connections is important in endothelial barrier function?
Your Answer: Gap junctions
Correct Answer: Tight junctions
Explanation:Tight junctions surround the apical margins of the epithelial cells such as in the intestinal mucosa and the choroid plexus. They are also important to the endothelial barrier function. They are made up of ridges that adhere to each other strongly at the cell junction, obliterating the space completely between the cells.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 43
Correct
-
A 41 year old woman who has a history of SLE presents with a dry cough, dyspnoea and fever. She is being treated with a monthly dose of IV cyclophosphamide for Grade IV nephropathy. The last cyclophosphamide dose was 10 years ago. Lab investigations are as follows: WCC: 2.3 (lymphocyte count 0.7)Platelets: 81Hb: 10.5ESR: 56CRP: 43PO2: 7.2 kPa, PCO2: 3.6 kPa after walking out to the toilet.Chest X ray was unremarkable apart from some patchy pulmonary infiltration.What is the likely diagnosis?
Your Answer: Pneumocystis carinii pneumonia (PCP)
Explanation:Pneumocystis carinii pneumonia, is an opportunistic fungal lung infection occurring almost exclusively in immunocompromised individuals. In 50% of cases, PCP is the first manifestation of AIDS (acquired immune deficiency syndrome), but it may be caused by other immunodeficiency disorders. PCP should be suspected in patients with a history of progressive dyspnoea and a dry cough with resistance to standard antibiotic treatment. Signs that support this diagnosis include a CD4 count < 200/μL, an increased beta-D-glucan level, and diffuse bilateral infiltrates on chest x-ray. Management of PCP includes high-dose trimethoprim/sulfamethoxazole (TMP/SMX), treatment of the underlying immunodeficiency disorder, and steroids in the case of severe respiratory insufficiency. TB is less likely to be present in this case as ESR is relatively low and chest x-ray appeared normal.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 44
Incorrect
-
Normally the portal venous pressure is about:
Your Answer: 15mmhg
Correct Answer: 5mmhg
Explanation:Under normal physiological conditions, the pressure in the portal vein, which carries blood from the gastrointestinal tract and spleen to the liver, typically ranges around 5-10 mmHg. Pressures significantly higher than this range can indicate portal hypertension, which can be associated with liver diseases such as cirrhosis.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 45
Incorrect
-
The pyloric sphincter is largely made up of thickening of
Your Answer: Both the oblique and the circular muscle layers
Correct Answer: The circular muscle layer
Explanation:The pyloric sphincter, or valve, is a strong ring of smooth muscle (circular muscle layer) at the end of the pyloric canal which lets food pass from the stomach to the duodenum. It controls the outflow of gastric contents into the duodenum. It receives sympathetic innervation from the celiac ganglion.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 46
Correct
-
In most somatic cells telomeres progressively shorten as:
Your Answer: The cell divides
Explanation:Telomerase activity is seen in germ cells and is absent in somatic cells. A somatic cell is any biological cell forming the body of an organism, other than a gamete, germ cell, gametocyte or undifferentiated stem cell. i.e. liver cells. Telomeres prevent the chromosomes from shortening and prevent the coding portion of the DNA from being lost, thus allowing the cell to replicate indefinitely. During replication telomeres may be lost resulting in cell death.
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 47
Incorrect
-
Where is Vitamin B 12 absorbed?
Your Answer: Jejunum
Correct Answer: Terminal ileum
Explanation:Protein-bound vitamin B12 must be released from the proteins by the action of digestive proteases in both the stomach and small intestine. Gastric acid releases the vitamin from food particles; therefore antacid and acid-blocking medications (especially proton-pump inhibitors) may inhibit absorption of B12. B12 must be attached to Intrinsic Factor (IF) for it to be efficiently absorbed, as receptors on the enterocytes in the terminal ileum of the small bowel only recognize the B12-IF complex; in addition, intrinsic factor protects the vitamin from catabolism by intestinal bacteria.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 48
Correct
-
Regarding restriction fragment length polymorphisms (RFLP) and Gene Knockout Mouse Models. All are true except:
Your Answer: In knockout mouse models a gene is turned on through targeted mutation
Explanation:In RFLP, polymorphism occurs in 98% of the non coding genome, resulting in no phenotypical change in the organism. A gene is not turned on by a mutation, rather the mutation at the restriction site will alter the DNA and the DNA will now form fragments of different lengths. PCR is a better technique than RFLP.
A knockout, as related to genomics, refers to the use of genetic engineering to inactivate or remove one or more specific genes from an organism. Scientists create knockout organisms to study the impact of removing a gene from an organism, which often allows them to then learn something about that gene’s function.
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 49
Incorrect
-
With regards to the cardiac cycle which of the following is true
Your Answer: Left ventricular contraction begins after right ventricular contraction
Correct Answer: Right atrial systole occurs before left atrial systole: as below
Explanation:Cardiac cycle: The first event in the cycle is atrial depolarization (a P wave on the surface ECG) follows by RIGHT ATRIAL and then LEFT ATRIAL contraction. Ventricular activation (QRS) follows after a short interval (the PR interval). LEFT VENTRICULAR contraction starts shortly thereafter RIGHT VENTRICULAR contraction begins. At the end, the aortic valve closure is followed by pulmonary valve closure.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 50
Correct
-
Which of the following can trigger parietal cell secretion?
Your Answer: Gastrin
Explanation:The three agonists of parietal cell secretion are gastrin, acetylcholine and histamine. Parietal cells are responsible for the secretion of HCl and intrinsic factor.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
SESSION STATS - PERFORMANCE PER SPECIALTY
