-
Question 1
Correct
-
Where is angiotensinogen produced?
Your Answer: Liver
Explanation:Angiotensin is a peptide hormone that causes vasoconstriction and a subsequent increase in blood pressure. Angiotensin also stimulates the release of aldosterone from the adrenal cortex. Aldosterone promotes sodium retention in the distal nephron, in the kidney, which also drives blood pressure up. It is derived from the precursor molecule angiotensinogen, a serum globulin produced in the liver.
-
This question is part of the following fields:
- Medicine
- Renal
-
-
Question 2
Incorrect
-
The Na-K-2Cl co-transporter occurs in which part of the renal tubule?
Your Answer: Basolateral surface of thick ascending limb
Correct Answer: Apical surface of thick ascending limb
Explanation:The Na-K-Cl cotransporter (NKCC) is a protein that aids in the active transport of sodium, potassium, and chloride into cells. In humans there are two isoforms of this membrane transport protein, NKCC1 and NKCC2. NKCC2 is specifically found in cells of the thick ascending limb of the loop of Henle and the macula densa in nephrons, the basic functional units of the kidney. Within these cells, NKCC2 resides in the apical membrane abutting the nephron’s lumen.
-
This question is part of the following fields:
- Medicine
- Renal
-
-
Question 3
Correct
-
Where is the site of action of spironolactone?
Your Answer: Distal convoluted tubule
Explanation:Spironolactone is an aldosterone antagonist which acts in the distal convoluted tubule. It is a potassium-sparing diuretic that prevents the body from absorbing too much salt and keeps the potassium levels from getting too low. Spironolactone is used to treat heart failure, high blood pressure (hypertension), or hypokalaemia (low potassium levels in the blood).
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 4
Correct
-
The liver is the principal site for?
Your Answer: Storage of iron
Explanation:The liver mainly synthesizes proteins including albumin, globulins and coalgulative factors. Vitamin B12 is taken in via the diet and stored by the liver. Vitamin C is not stored and excessive vitamin C is excreted via urine. Liver is the main site of iron storage, where it is stored in the form of ferritin.
-
This question is part of the following fields:
- Hepatobiliary
- Medicine
-
-
Question 5
Incorrect
-
In a normal heart rate at rest, the left ventricular end-diastolic volume is ….
Your Answer: 50-70 ml
Correct Answer: 100-130 ml
Explanation:In cardiovascular physiology, end-diastolic volume (EDV) is the volume of blood in the right and/or left ventricle at end load or filling in (diastole) or the amount of blood in the ventricles just before systole. Because greater EDVs cause greater distention of the ventricle, EDV is often used synonymously with preload, which refers to the length of the sarcomeres in cardiac muscle prior to contraction (systole). End-diastolic volume: Right = 144 mL(± 23mL) & Left = 142 mL (± 21 mL).
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 6
Correct
-
Calcium induced calcium release occurs in the sarcoplasmic reticulum by activation of which receptors
Your Answer: Ryanodine receptors
Explanation:Calcium-induced calcium release (CICR) describes a biological process whereby calcium is able to activate calcium release from intracellular Ca2+ stores (e.g., endoplasmic reticulum or sarcoplasmic reticulum). CICR occurs when the resulting Ca2+ influx activates ryanodine receptors on the SR membrane, which causes more Ca2+ to be released into the cytosol.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 7
Correct
-
The principal enzyme of lipid digestion is:
Your Answer: Lipase
Explanation:Lipase is the principle enzyme that digest lipids. Amylase digest carbohydrates. Colipase is a co-enzyme that optimize the activity of lipase. Trypsin digest proteins and cholesterol esterase digest cholesterol.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 8
Correct
-
A 32 year old complains of pain in her hands bilaterally. Which of the following symptoms would point towards an inflammatory joint disease such as rheumatoid arthritis?
Your Answer: Marked stiffness for more than an hour in the mornings
Explanation:In rheumatoid arthritis (RA), clinical symptoms of joint stiffness, pain, and functional disability are commonly most severe in the early morning. These symptoms closely follow the circadian rhythm of the pro-inflammatory cytokine, interleukin (IL)-6. In RA, the increase in nocturnal anti-inflammatory cortisol secretion is insufficient to suppress ongoing inflammation, resulting in the morning symptoms characteristic of RA. Established diagnostic criteria for RA include prolonged morning stiffness that could last up to an hour. Loss of joint mobility, pain, malaise and swelling of finger joints are features that are not specific to rheumatoid arthritis, and are found in many other conditions.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 9
Incorrect
-
With regards to the function of the p53 protein produced by the p53 gene, which of the following statements is incorrect?
Your Answer: Mutations in this protein may slow down the cell cycle causing mutations to persist
Correct Answer: It permits repair of mutations and other defects in RNA
Explanation:The p53 protein is a crucial tumor suppressor and plays several key roles in maintaining cellular integrity:
- Nuclear transcription factor: p53 is a nuclear transcription factor that regulates the expression of various genes involved in cell cycle control, DNA repair, apoptosis, and senescence.
- DNA repair: p53 permits repair of mutations and other defects in DNA (not RNA). It activates the transcription of genes involved in DNA repair mechanisms, allowing the cell to correct errors before proceeding with the cell cycle.
- Cell cycle regulation: p53 can induce the expression of p21, a protein that inhibits cyclin-dependent kinases, thereby halting the cell cycle at the G1/S checkpoint to allow time for DNA repair or to trigger apoptosis if the damage is irreparable. Mutations in p53 may fail to halt the cell cycle, allowing mutations to persist and potentially leading to cancer.
- Apoptosis: If DNA damage is extensive and cannot be repaired, p53 triggers apoptosis to prevent the propagation of damaged cells.
- Suppression of proto-oncogenes: p53 indirectly contributes to the suppression of proto-oncogenes by preventing the proliferation of cells with damaged DNA, thereby reducing the risk of oncogenic transformation.
Given these functions, the statement that p53 “permits repair of mutations and other defects in RNA” is incorrect, as p53 is primarily involved in the repair of DNA, not RNA.
-
This question is part of the following fields:
- Cell Biology
- Medicine
-
-
Question 10
Correct
-
Which of the following statements regarding psoriasis is incorrect?
Your Answer: Mediated by type 2 helper T cells
Explanation:Psoriasis is a long-lasting autoimmune disease characterized by patches of skin typically red, dry, itchy, and scaly. Psoriasis can affect the nails and produces a variety of changes in the appearance of finger and toe nails including pitting and onycholysis. Nail psoriasis occurs in 40–45% of people with psoriasis affecting the skin and has a lifetime incidence of 80–90% in those with psoriatic arthritis. Psoriasis is mediated by type 1 helper T cells which are involved in the cell mediated response.
-
This question is part of the following fields:
- Dermatology
- Medicine
-
-
Question 11
Correct
-
The heart rate can be accelerated by:
Your Answer: Exercise and thyroid hormones
Explanation:The firing of the SA node will increase due to exercises and as the thyroid hormone has a chronotropic effect on the heart, it too will result in an increase in the heart rate via stimulation of the adrenergic receptors of the heart. As during exercise the sympathetic nervous system is activated, it will directly have an positive chronotropic effect on the heart.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 12
Correct
-
Which enzyme deficiency causes Beriberi?
Your Answer: Thiamine
Explanation:Beriberi refers to a cluster of symptoms caused primarily by thiamine (vitamin B1) deficiency. Symptoms of beriberi include weight loss, emotional disturbances, impaired sensory perception, weakness and pain in the limbs, and periods of irregular heart rate.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 13
Correct
-
The primary auditory cortex is:
Your Answer: Brodmann area 41
Explanation:A Brodmann area in the brain is defined by cytoarchitecture, histology and organization of cells:Primary Sensory 3,1,2Primary Motor 4Premotor 6Primary Visual 17Primary Auditory 41Brocas 44
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 14
Correct
-
Which of the following is the correct way to calculate the anion gap?
Your Answer: (Na + K) – (HCO3 + Cl)
Explanation:The anion gap is the difference between the measured cations (positively charged ions) and the measured anions (negatively charged ions) in serum, plasma, or urine. The magnitude of this difference in the serum is often calculated in medicine when attempting to identify the cause of metabolic acidosis. Anion Gap = ([Na+] + [K+]) − ([Cl−] + [HCO−3])
-
This question is part of the following fields:
- Medicine
- Renal
-
-
Question 15
Correct
-
Protein digestion starts in the stomach by which enzyme?
Your Answer: Pepsin
Explanation:Pepsinogen is the inactive form of pepsin which is secreted by gastric chief cells and is converted to pepsin, in the presence of gastric HCL. Pepsin is a peptidase that breaks down proteins into smaller peptides.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 16
Incorrect
-
Which one of the following features is least associated with primary hyperparathyroidism?
Your Answer: Peptic ulceration
Correct Answer: Sensory loss
Explanation:The signs and symptoms of primary hyperparathyroidism are those of hypercalcemia. They are classically summarized by stones, bones, abdominal groans, thrones and psychiatric overtones.
Stones refers to kidney stones, nephrocalcinosis, and diabetes insipidus (polyuria and polydipsia). These can ultimately lead to renal failure.
Bones refers to bone-related complications: osteitis fibrosa cystica, osteoporosis, osteomalacia, and arthritis.
Abdominal groans refers to gastrointestinal symptoms of constipation, indigestion, nausea and vomiting. Hypercalcemia can lead to peptic ulcers and acute pancreatitis.
Thrones refers to polyuria and constipation
Psychiatric overtones refers to effects on the central nervous system. Symptoms include lethargy, fatigue, depression, memory loss, psychosis, ataxia, delirium, and coma.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 17
Incorrect
-
Which is the most common site for primary cardiac tumours to occur in adults?
Your Answer: Right atrium
Correct Answer: Left atrium
Explanation:Myxomas are the most common type of primary heart tumour. The tumour is derived from multipotential mesenchymal cells and may cause a ball valve-type obstruction. About 75% of myxomas occur in the left atrium of the heart, usually beginning in the wall that divides the two upper chambers of the heart.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 18
Correct
-
Which of the following affects the magnitude of the action potential?
Your Answer: Changes in the external Na+ concentration
Explanation:The magnitude of the action potential is determined by the sodium current. Increase in external sodium will result in increased influx of sodium and hence generation of a stronger action potential.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 19
Correct
-
Which of the following is not a feature of Liddle’s syndrome?
Your Answer: Autosomal recessive inheritance
Explanation:Liddle’s syndrome is a rare autosomal dominant condition characterized by early, and frequently severe, high blood pressure associated with low plasma renin activity, metabolic alkalosis, low blood potassium, and normal to low levels of aldosterone. Liddle syndrome involves abnormal kidney function, with excess reabsorption of sodium and loss of potassium from the renal tubule, and is treated with a combination of low sodium diet and potassium-sparing diuretic drugs (e.g., amiloride).
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 20
Correct
-
The mechanism of action of low molecular weight heparin, has the greatest effect on which of the following components of the coagulation cascade?
Your Answer: Factor Xa
Explanation:Mechanism of action of low molecular weight heparin (LMWH): It inhibits coagulation by activating antithrombin III. Antithrombin III binds to and inhibits factor Xa. In doing so it prevents activation of the final common path; Xa inactivation means that prothrombin is not activated to thrombin, thereby not converting fibrinogen into fibrin for the formation of a clot. LMHW is a small fragment of a larger mucopolysaccharide, heparin. Heparin works similarly, by binding antithrombin III and activating it. Heparin also has a binding site for thrombin, so thrombin can interact with antithrombin III and heparin, thus inhibiting coagulation. Heparin has a faster onset of anticoagulant action as it will inhibit not only Xa but also thrombin, while LMWH acts only on Xa inhibition.Compared to heparin, LMWHs have a longer half-life, so dosing is more predictable and can be less frequent, most commonly once per day.Dosage and uses:LMWH is administered via subcutaneous injection. This has long-term implications on the choice of anticoagulant for prophylaxis, for example, in orthopaedic patients recovering from joint replacement surgery, or in the treatment of DVT/PE.Adverse effects:The main risk of LMWH will be bleeding. The specific antidote for heparin-induced bleeding is protamine sulphate.Less commonly it can cause:Heparin-induced thrombocytopenia (HIT)Osteoporosis and spontaneous fracturesHypoaldosteronismHypersensitivity reactions
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 21
Correct
-
The initial rapid depolarization in the action potential of cardiac muscle cells is due to:
Your Answer: Opening of voltage-gated Na+ channels
Explanation:The initial depolarization of the action potential in a cardiac muscle cell is due to the sodium current generated by opening of the voltage gated sodium channels leading to an influx of sodium ions into the cell and raising the membrane potential towards threshold.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 22
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 23
Correct
-
The Sinoatrial node in the majority of people is supplied by the?
Your Answer: Right coronary artery
Explanation:In 60% of people, the SA node is supplied by the right coronary artery branch and in 40% of the people by the left coronary artery.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 24
Correct
-
In most somatic cells telomeres progressively shorten as:
Your Answer: The cell divides
Explanation:Telomere length shortens with age. Progressive shortening of telomeres leads to senescence, apoptosis, or oncogenic transformation of somatic cells, affecting the health and lifespan of an individual. 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 25
Correct
-
Visual pathways - Choose the true statement:
Your Answer: The lateral geniculate nucleus, magnocellular & parvocellular pathways project to the primary visual cortex
Explanation:The optic chiasm is made by the decussation of optic fibers on the nasal side. The magnocellular pathway carries signals for detection of movement. The parvocellular pathway carries cells for detection of shape, size, colour and clarity. The lateral geniculate nucleus (LGN) is the relay centre in the thalamus for he visual pathway. It has layers of magnocellular cells and parvocellular cells that are interleaved with layers of koniocellular cells. The LGN is the main central connection for the optic nerve to the occipital lobe, particularly the primary visual cortex.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 26
Correct
-
In paralytic ileus the following are true except:
Your Answer: Opioid blocking drugs will exacerbate the symptoms
Explanation:Paralytic ileus causes adynamic intestinal obstruction or decreased peristalsis and the most common reason being postoperative ileus. Opioid drugs like morphine are given for pain management and cause decreased peristalsis in the gut resulting in constipation. Theoretically opioid blocking drugs or opioid antagonists can increase peristalsis and can alleviate paralytic ileus symptoms.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 27
Incorrect
-
The extrinsic coagulation pathway is initiated by activation of which clotting factor?
Your Answer: Factor II
Correct Answer: Factor VII
Explanation:The tissue factor pathway (extrinsic) begins following damage to the blood vessel. FVII leaves the circulation and comes into contact with tissue factor (TF) expressed on tissue-factor-bearing cells (stromal fibroblasts and leukocytes), forming an activated complex (TF-FVIIa).
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 28
Incorrect
-
Male to male transmission is a key factor of which type of inheritance?
Your Answer: X linked recessive
Correct Answer: Autosomal dominant
Explanation:Autosomal dominant type of inheritance can include both sexes in the same ratio. There is no skipping a generation and father to son transmission is common. The passing of the trait is sex independent.
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 29
Correct
-
Consanguinity shows a strong association with which pattern of inheritance?
Your Answer: Autosomal recessive
Explanation:Consanguinity involves being from the same kinship as another person. It is a common feature of an autosomal recessive mode of inheritance
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 30
Incorrect
-
In RFLP (restriction fragment length polymorphism), the DNA fragments are separated by length through a process known as:
Your Answer: Insertion
Correct Answer: Agarose gel electrophoresis
Explanation:Samples of DNA from individuals are broken into pieces by restriction enzymes and the fragments are separated according to their lengths via gel electrophoresis. Although now largely obsolete due to the rise of inexpensive DNA sequencing technologies, RFLP analysis was the first DNA profiling technique inexpensive enough to see widespread application.
-
This question is part of the following fields:
- Genetics
- Medicine
-
SESSION STATS - PERFORMANCE PER SPECIALTY
