-
Question 1
Incorrect
-
The main reason for the prolonged effect of the withdrawal reflex is:
Your Answer: Slow efferent conduction
Correct Answer: Multiple connections between afferent and efferent neurons
Explanation:The withdrawal reflex is a spinal reflex that protects the body from harmful stimuli. Spinal reflexes are mostly monosynaptic and are mediated by a simple reflex arc. Withdrawal reflex is mediated by a polysynaptic reflex resulting in stimulation of many motor neurons in order to establish a quick and prolonged response.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 2
Correct
-
Which is NOT true of vitiligo?
Your Answer: A positive family history is not a risk factor
Explanation:The cause of Vitiligo is typically unknown. It is believed to be due to genetic susceptibility that is triggered by an environmental factor such that an autoimmune disease occurs. This results in the destruction of skin pigment cells. Risk factors include a family history of the condition or other autoimmune diseases, such as hyperthyroidism, alopecia areata, and pernicious anaemia. Vitiligo is classified into two main types: segmental and non-segmental. Most cases are non-segmental meaning they affect both sides and typically get worse with time. The prevalence of vitiligo is 0.5-1% of populations worldwide. Typical sites include backs of hands, wrists, knees, neck and around body orifices. The Koebner phenomenon refers to skin lesions appearing on lines of trauma. This occurs in vitiligo secondary to scratching.
-
This question is part of the following fields:
- Dermatology
- Medicine
-
-
Question 3
Correct
-
Which of the following features occurs very less frequently with drug induced lupus?
Your Answer: Glomerulonephritis
Explanation:Drug induced lupus typically presents with pulmonary involvement and no renal or neurological involvement. Hence glomerulonephritis would be highly unlikely in this case. Rash and arthralgias are classic presentations. Pleurisy can be present as pulmonary involvement may occur with DILE.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 4
Correct
-
What is the average life span of red blood cells?
Your Answer: 4 months
Explanation:Approximately 2.4 million new erythrocytes are produced per second in human adults. The cells develop in the bone marrow and circulate for about 100ā120 days (4 months) in the body before their components are recycled by macrophages.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 5
Correct
-
In a normal heart rate at rest, the left ventricular end-diastolic volume is ā¦.
Your 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(Ā± 23mL) & Left = 142 mL (Ā± 21 mL).
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 6
Correct
-
An obstruction in a pulmonary artery causes impaired perfusion to an area in the lung. The gas values in the unperfused alveoli at sea level will be:
Your Answer: PO2 = 149 C02 =0
Explanation:Partial pressure of oxygen at sea level is approximately 160 mmHg. Partial pressure of oxygen in alveoli is around 150 mmHg and in an arteriole is around 80-100 mmHg. Partial pressure of carbon dioxide is around 35 mmHg in alveolar air and around 40 mmHg in the arteriole.
-
This question is part of the following fields:
- Medicine
- Respiratory
-
-
Question 7
Correct
-
Concerning the sleep-wake cycle, Melatonin is secreted by which structure in the brain following which environmental conditions?
Your Answer: Pineal gland, darkness
Explanation:Melatonin is secreted by the pineal gland located in the midline attached to the posterior roof of the third ventricle in the brain. Melatonin affects circadian rhythm in the body or the sleep wake cycle. The precursor to melatonin is serotonin and the rate limiting enzyme that converts serotonin to melatonin is low during the day time and reaches its peak during the night.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 8
Correct
-
Regarding cardiac contractility, catecholamines exert their inotropic effect via:
Your Answer: Ī1-adrenergic receptors and gs
Explanation:Catecholamines exert their inotropic effect on the heart via the B1 adrenergic receptors and Gs, stimulating adenyl cyclase and increasing the production of cAMP.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 9
Correct
-
The pathogen in variant Creutzfeldt Jacobs disease is an example of a:
Your Answer: Prion
Explanation:Types of Creutzfeldt Jacobs Disease (CJD) include:1. variant – This is thought to be caused by the consumption of food contaminated with prions, which also cause BSE.2. sporadic – This accounts for 85% of cases of CJD. 3. familial – This accounts for the majority of the other 15% cases of CJD.4. iatrogenic – This form of CJD arises from contamination with tissue from an infected person, usually as the result of a medical procedure.
-
This question is part of the following fields:
- Infectious Diseases
- Medicine
-
-
Question 10
Correct
-
Question 11
Incorrect
-
Select the correct statement regarding the 4th heart sound, it?
Your Answer: Coincides with the ācā wave in the JVP.
Correct Answer: Can be heard in atrial systole.
Explanation:The fourth heart sound is not normally audible in a normal adult. It occurs as a consequence of ventricular hypertrophy. It is caused by filling of the ventricle by atrial systole.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 12
Correct
-
Which of the following with regard to autosomal dominant disorders are true:
Your Answer: The offspring of a heterozygous individual has a 50% chance of inheriting the chromosome carrying the disease allele
Explanation:50% of the children will be effected from parents who are heterozygous for an autosomal dominant disorder. An allele can be dominant or recessive. Individuals, meanwhile, can be homozygous or heterozygous: individuals who are homozygous for a certain gene carry two copies of the same allele. individuals who are heterozygous for a certain gene carry two different alleles.
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 13
Correct
-
What landmark divides the frontal and parietal lobes?
Your Answer: Central sulcus
Explanation:The central sulcus divides the frontal lobe from the parietal lobe. It contains the motor cells for the movement function of the body.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 14
Correct
-
Which of the following foods contain Vitamin B 12?
Your Answer: Liver, meat
Explanation:No fungi, plants, nor animals (including humans) are capable of producing vitamin B12. Only bacteria and archaea have the enzymes needed for its synthesis. Proved food sources of B12 are animal products (meat, fish, dairy products).
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 15
Correct
-
Which one of the following is not part of the WHO diagnostic criteria for the metabolic syndrome?
Your Answer: High LDL
Explanation:The World Health Organization 1999 criteria require the presence of any one of diabetes mellitus, impaired glucose tolerance, impaired fasting glucose or insulin resistance, AND two of the following:
- Blood pressure: ā„ 140/90 mmHg
- Dyslipidaemia: triglycerides (TG): ā„ 1.695 mmol/L and high-density lipoprotein cholesterol (HDL-C) ā¤ 0.9 mmol/L (male), ā¤ 1.0 mmol/L (female)
- Central obesity: waist: hip ratio > 0.90 (male); > 0.85 (female), or body mass index > 30 kg/m2
- Microalbuminuria: urinary albumin excretion ratio ā„ 20 Āµg/min or albumin: creatinine ratio ā„ 30 mg/g
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 16
Incorrect
-
Which of the following drugs is NOT bacteriostatic?
Your Answer: Sulphonamides
Correct Answer: Penicillin
Explanation:Bactericidal antibiotics kill bacteria directly whereas bacteriostatic antibiotics slow their growth or reproduction. Tetracycline is a bacteriostatic antibiotic. Erythromycin which is a macrolide is mainly a bacteriostatic antibiotic but can show bactericidal action depending on the dose. Sulphonamides are mainly bacteriostatic. Penicillin inhibits cell wall synthesis therefore it is considered as bactericidal. Chloramphenicol is primarily a bacteriostatic antibiotic which inhibits protein synthesis and can exhibit bactericidal action in high concentrations.
-
This question is part of the following fields:
- Infectious Diseases
- Medicine
-
-
Question 17
Correct
-
Cross-bridges between actin and myosin filaments contain:
Your Answer: Calcium ions
Explanation:At rest troponin I is bound to actin and tropomyosin and covers the site where the myosin head interacts with actin. When calcium enters into the muscle, it binds with troponin C and causes a structural change in troponin I which moves out of the myosin binding site and causes the cross bridges between the actin and myosin filaments to occur.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 18
Correct
-
Transport of Ca2+ into the reticulum to initiate cardiac muscle relaxation in via:
Your Answer: Serca (sarcoplasmic or endoplasmic reticulum Ca2+ ATPase)
Explanation:Phosphorylation of phospholamban, which increases calcium ATPase activity and sequestration of calcium in the sarcoplasmic reticulum. An increased rate of relaxation is explained because cAMP also activates the protein phospholamban, situated on the membrane of the SR, that controls the rate of uptake of calcium into the SR. The latter effect explains enhanced relaxation (lusitropic effect).
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 19
Correct
-
Microtubule disassembly:
Your Answer: Occurs at the positive and negative end
Explanation:Dynamic instability refers to the coexistence of assembly and disassembly at the ends of a microtubule. The microtubule can dynamically switch between growing and shrinking phases in this region. Although both assembly and disassembly occur at both ends they occur preferentially at the (+) end.
-
This question is part of the following fields:
- Cell Biology
- Medicine
-
-
Question 20
Incorrect
-
Somatostatin is responsible for?
Your Answer: Increased pancreatic secretions
Correct Answer: Decreased gastrin release
Explanation:Somatostatin is an inhibitory hormone secreted from the D cells of the Pancreatic Islets. It causes the inhibition of gastrin (decreasing stomach acid production), CCK (decreasing gallbladder motility), gastrin inhibitory peptide and secretin. Gastrin production is also inhibited by secretin, GIP, VIP, glucagon and calcitonin.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 21
Incorrect
-
Almost all of the protein that appears in the stool is:
Your Answer:
Correct Answer: Comes from bacteria and cellular debris
Explanation:75% of faecal weight is water. By dry weight 30% of faeces is bacteria,10-20% is fat and 2-3% proteins. Almost all proteins ingested are absorbed in the gut.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 22
Incorrect
-
Iron absorption occurs primarily in which part of the GIT?
Your Answer:
Correct Answer: Duodenum
Explanation:Like most mineral nutrients, the majority of the iron absorbed from digested food or supplements is absorbed in the duodenum by enterocytes of the duodenal lining.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 23
Incorrect
-
Endolymph in the inner ear is rich in:
Your Answer:
Correct Answer: K
Explanation:Cochlear fluids namely endolymph and perilymph have different compositions. Perilymph is a typical extracellular fluid, with ionic composition comparable to plasma or cerebrospinal fluid. The main cation is sodium. Endolymph is a totally unique extracellular fluid, with an ion composition unlike that which is found anywhere else in the body. The major cation in the endolymph is potassium and there is virtually no sodium.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 24
Incorrect
-
Stimulation of the carotid sinus results in:
Your Answer:
Correct Answer: Drop in blood pressure
Explanation:Stimulation of the carotid sinus will result in an increase in the baroreceptor discharge. This will travel via the afferent nerves to the medulla. Signals will pass through the vagus nerve to decrease the sympathetic outflow to the heart and the blood vessels. This inhibition will result in vasodilation of the blood vessels, venodilation and bradycardia hence decreasing the total peripheral resistance and lowering the blood pressure.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 25
Incorrect
-
What catalyses the conversion of adenosine to inosine?
Your Answer:
Correct Answer: Adenosine deaminase
Explanation:Adenosine deaminase (ADA) is an enzyme involved in purine metabolism. It is needed for the breakdown of adenosine from food and for the turnover of nucleic acids in tissues. ADA irreversibly deaminates adenosine, converting it to the related nucleoside inosine by the substitution of the amino group for a keto group.
-
This question is part of the following fields:
- Medicine
- Metabolism
-
-
Question 26
Incorrect
-
In Jugular vein pressure the āaā wave represents?
Your Answer:
Correct Answer: Atrial systole
Explanation:The jugular venous pressure (JVP, sometimes referred to as jugular venous pulse) is the indirectly observed pressure over the venous system via visualization of the internal jugular vein. It can be useful in the differentiation of different forms of heart and lung disease. Classically three upward deflections and two downward deflections have been described: The upward deflections are the a (atrial contraction), c (ventricular contraction and resulting bulging of tricuspid into the right atrium during isovolumetric systole) and v = venous filling.The downward deflections of the wave are the x (the atrium relaxes and the tricuspid valve moves downward) and the y descent (filling of ventricle after tricuspid opening).
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 27
Incorrect
-
With regard to the endothelial structure, the epithelium constitute:
Your Answer:
Correct Answer: Simple squamous
Explanation:The single layer of squamous epithelium lining the heart and blood vessels is known as the endothelium.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 28
Incorrect
-
Where is Vitamin B 12 absorbed?
Your Answer:
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 29
Incorrect
-
Which of the following is NOT an effect of a positive inotropic agent on the heart?
Your Answer:
Correct Answer: It decreases the rate of rise in ventricular blood pressure during systole
Explanation:Inotropic agents increase the contractility of the heart as well as the rate of rise in ventricular blood pressure during systole, generating a greater pressure and increasing the stroke volume e.g. like catecholamines do.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 30
Incorrect
-
Question 31
Incorrect
-
Regarding CSF:
Your Answer:
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 32
Incorrect
-
Which statement about antithrombin III is true?
Your Answer:
Correct Answer: It inhibits particularly factor II and X
Explanation:Antithrombin inactivates its physiological target enzymes, Thrombin (Factor II), Factor Xa and Factor IXa. ATIII binds to thrombin and then forms the thrombin-anti thrombin complex or TAT complex. This is a major natural pathway of anticoagulation. This binding of thrombin to AT is greatly enhanced in the presence of heparin.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 33
Incorrect
-
Which statement describes endogenous transmission the best?
Your Answer:
Correct Answer: Commensal flora that gain access to an inappropriate area
Explanation:All answers A, B, C, and D are examples of exogenous infections. Endogenous infection is an infection by organisms that normally reside in the body but have previously been dormant.
-
This question is part of the following fields:
- Infectious Diseases
- Medicine
-
-
Question 34
Incorrect
-
In the Fickās method of measuring cardiac output, the arterial oxygen content can be measured in a sample obtained from
Your Answer:
Correct 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 ā Cv) is also known as the arteriovenous oxygen difference.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 35
Incorrect
-
Question 36
Incorrect
-
A 51-year-old real estate agent takes hydrocortisone 20mg in the mornings and 5mg at night for Addisonās disease. The endocrinology consultant would like her to take prednisolone instead. What dose of prednisolone should be started?
Your Answer:
Correct Answer: 7 mg
Explanation:1mg Prednisolone = 4mg hydrocortisone, so the actual equivalent daily dose is 7mg.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 37
Incorrect
-
Which of the following foods do NOT contain high levels of folate?
Your Answer:
Correct Answer: Yellow vegetables
Explanation:Folate naturally occurs in a wide variety of foods, including vegetables (particularly dark green leafy vegetables), fruits and fruit juices, nuts, beans, peas, dairy products, poultry and meat, eggs, seafood, grains, and some beers. Avocado, beetroot, spinach, liver, yeast, asparagus, and Brussels sprouts are among the foods with the highest levels of folate
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 38
Incorrect
-
An effect of aging on the kidney includes?
Your Answer:
Correct Answer: Decreased GFR
Explanation:The normal range of GFR, adjusted for body surface area, is 100 to 130 mL/min/1.73m2 in men and 90 to 120 ml/min/1.73m2 in women younger than the age of 40. After age 40, GFR decreases progressively with age, by about 0.4 mL/min to 1.2 mL/min per year.
-
This question is part of the following fields:
- Medicine
- Renal
-
-
Question 39
Incorrect
-
Which of the following initiates migrating motor complex
Your Answer:
Correct Answer: Motilin
Explanation:Migrating motor complexes (MMC) are thought to be partially regulated by motilin, which is initiated in the stomach as a response to vagal stimulation, and does not directly depend on extrinsic nerves.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 40
Incorrect
-
The basic taste āumamiā is mediated by glutamate acting on a metabotropic receptor named:
Your Answer:
Correct Answer: mGluR4
Explanation:Umami taste or savoury taste is one of the five basic tastes described as meaty or brothy. Umami taste receptors typically respond to Glutamate. Biochemical studies have identified the taste receptors responsible for the sense of umami as modified forms of mGluR4, mGluR1 and taste receptor type 1 (T1R1), all of which have been found in all regions of the tongue bearing taste buds.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 41
Incorrect
-
A 50-year-old hypertensive male on phenytoin and clobazam for partial seizures is also taking lisinopril, cimetidine, sucralfate, and allopurinol. The last few drugs were added recently. He now presents with ataxia, slurred speech, and blurred vision.Which recently added drug is most likely to be the cause of his latest symptoms?
Your Answer:
Correct Answer: Cimetidine
Explanation:The symptoms of ataxia, slurred speech and blurred vision are all suggestive of phenytoin toxicity. Cimetidine increases the efficacy of phenytoin by reducing its hepatic metabolism.Phenytoin has a narrow therapeutic index (10-20 mg/L) and its levels are monitored by measuring the total phenytoin concentration.Cimetidine is an H2 receptor antagonist used in the treatment of peptic ulcers. It acts by decreasing gastric acid secretion.Cimetidine also has an inhibitory effect on several isoforms of the cytochrome enzyme system including the CYP450 enzymatic pathway. Phenytoin is metabolized by the same cytochrome P450 enzyme system in the liver. Thus, the simultaneous administration of both these medications leads to an inhibition of phenytoin metabolism and thus increases its circulating levels leading to phenytoin toxicity.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 42
Incorrect
-
Which of the following is the most common route of hepatitis B transmission worldwide?
Your Answer:
Correct Answer: Perinatal transmission
Explanation:The virus is transmitted by exposure to infectious blood or body fluids. Infection around the time of birth or from contact with other people’s blood during childhood is the most frequent method by which hepatitis B is acquired in areas where the disease is common. In areas where the disease is rare, intravenous drug use and sexual intercourse are the most frequent routes of infection. Perinatal transmission is the most common and without intervention, a mother who is positive for HBsAg has a 20% risk of passing the infection to her offspring at the time of birth. This risk is as high as 90% if the mother is also positive for HBeAg.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 43
Incorrect
-
The initial rapid depolarization in the action potential of cardiac muscle cells is due to:
Your Answer:
Correct 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 44
Incorrect
-
An 80 year old female, previously diagnosed with polymyalgia rheumatica 18 months back, presents to the outpatient clinic with bilateral shoulder stiffness and generalized myalgia. The ESR was found to be 60mm/1st hour at the time of presentation. Prednisolone therapy was initiated at a daily dose of 15 mg along with Calcium and Vitamin supplementation. She reported resolution of her symptoms in one week. However the symptoms relapsed when the prednisolone dose was reduced below the current dose of 12.5 mg daily. How should she be ideally managed?
Your Answer:
Correct Answer: Continue the current dose of prednisolone and start methotrexate
Explanation:Polymyalgia rheumatica, a syndrome characterized by proximal muscle pain and stiffness in older persons, generally is treated with prednisone. Dosages of 15 to 25 mg of prednisone per day can reduce inflammation considerably, although many patients relapse when therapy is tapered. Long-term (18 to 36 months) steroid treatment has been recommended by several studies, but this can result in multiple side effects, including osteoporosis, hypertension, cataracts, and hyperglycaemia. Methotrexate has been used to reduce inflammation in rheumatoid arthritis, systemic vasculitis, and giant cell arteritis, and in some studies has been combined with prednisone to treat polymyalgia rheumatica, decreasing the duration of treatment.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 45
Incorrect
-
All of the following constitute small intestinal brush border enzymes except:
Your Answer:
Correct Answer: Alpha-amylase
Explanation:The final step in digestion of carbohydrates, which is conversion of disaccharides to absorbable monosaccharides occurs on the small intestinal epithelial cells. The enzymes responsible for this final stage of digestion are not freely found in the intestinal lumen, but they are found as integral membrane proteins in the plasma membrane of the epithelial cell. The apical plasma membrane of the intestinal epithelial cell has numerous microvilli which extend from the cell known as the brush border. Thus, the enzymes embedded in those microvilli are referred to as brush border enzymes. All these enzymes except alfa amylase are brush border enzymes. Alfa amylase is secreted by pancreatic acinar cells.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 46
Incorrect
-
A 43 year old female presents with an array of symptoms including weakness, lethargy, dysphagia, dry mouth, gritty sensation in her eyes and increased photosensitivity. In order to confirm the suspected diagnosis, which of the following tests should be performed?
Your Answer:
Correct Answer: Labial gland biopsy
Explanation:To confirm the diagnosis, especially in patients with negative anti-Ro or anti-La antibodies, labial gland biopsy is done. In performing a labial biopsy, the surgeon typically makes a shallow 1/2 inch wide incision on either side of the inner lip after numbing the area with a local anaesthetic. Schirmer’s test determines whether the eye produces enough tears to keep it moist. This test can be done for ocular symptoms of Sjogren syndrome but is of no diagnostic importance as it can be positive with many other diseases.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 47
Incorrect
-
On which chromosome is the gene for insulin located?
Your Answer:
Correct Answer: Chromosome 11
Explanation:Humans have 23 pairs of chromosomes, and usually, two pairs of copies of chromosome 11. It is one of the most complex, gene-rich chromosomes in the human genome, and it is associated with a number of diseases. Studies have shown they the human insulin gene is located on the short arm of chromosome 11.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 48
Incorrect
-
Mutation in RB can lead to the formation of which cancer?
Your Answer:
Correct Answer: Retinoblastoma
Explanation:Patients with a history of autosomal dominant familial retinoblastoma have at least one mutated copy of the RB gene. This predisposes the patient to develop retinoblastoma in one or both the eyes. Patients with a family history should be screened properly so that it can be detected and treated as early as possible.
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 49
Incorrect
-
Which of the following is the correct way to calculate the anion gap?
Your Answer:
Correct Answer: (Na + K) ā (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+]) ā ([Clā] + [HCOā3])
-
This question is part of the following fields:
- Medicine
- Renal
-
-
Question 50
Incorrect
-
With regards to the cell cycle, which phase represents period of cell growth that divides the end of DNA synthesis and the beginning of somatic cell division?
Your Answer:
Correct Answer: Gap 2
Explanation:Interphase is divided into three phases: G1 (first gap), S (synthesis), and G2 (second gap). During all three parts of interphase, the cell grows by producing proteins and cytoplasmic organelles. However, chromosomes are replicated only during the S phase. Thus, a cell grows (G1), continues to grow as it duplicates its chromosomes (S), grows more and prepares for mitosis (G2), and finally divides (M) before restarting the cycle.
-
This question is part of the following fields:
- Cell Biology
- Medicine
-
-
Question 51
Incorrect
-
Which intestinal cells play a major role in secretory immunity?
Your Answer:
Correct Answer: M cells
Explanation:M cells are specialized epithelial cells of the MALT or mucosa-associated lymphoid tissues. They transport antigens from the intestinal lumen to cells of the immune system, thereby initiating an immune response. T and B cells are lymphocytes found in blood. Mucous cells secrete mucous and can be considered as a part of innate immunity. Chief cells in the gastric mucosa secret pepsin.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 52
Incorrect
-
The enzyme located on the brush border of the small intestine activating the proteolytic enzymes for further digestion of proteins is called?
Your Answer:
Correct Answer: Enterokinase
Explanation:Enterokinase is a brush border enzyme of the duodenum that activates proteolytic enzymes for further digestion of proteins. Trypsinogen is converted to trypsin by the action of enterokinase. Trypsin and chymotrypsin are secreted by the pancreatic acinar cells and are enzymes that aid in protein digestion. Pepsin is secreted by chief cells of the gastric mucosa. Procarboxydase is the inactive form of carboxypeptidase which is converted to its active form by trypsin and is secreted by pancreatic acinar cells.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 53
Incorrect
-
Visceral afferent fibers are found in the following areas except theā¦?
Your Answer:
Correct Answer: Trigeminal nerve
Explanation:The general visceral afferent (GVA) fibers carry impulses from viscera to the central nervous system. The cranial nerves that contain GVA fibers include the facial nerve, the glossopharyngeal nerve and the vagus nerve
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 54
Incorrect
-
Which of the following forms the language areas of the cerebral cortex?
Your Answer:
Correct Answer: All of the above
Explanation:Broca’s area, Wernicke’s area, the submarginal sulcus and the angular gyrus all form the language areas of the cerebral cortex.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 55
Incorrect
-
A 42 year old male arrives at the clinic due to cough and haemoptysis. Examination shows nasal mucosal ulceration. The doctor suspects Wegener's granulomatosis. Which anatomical area would be most commonly involved in this condition?
Your Answer:
Correct Answer: Lungs
Explanation:Granulomatosis with polyangiitis (GPA, previously known as Wegener’s granulomatosis) is a systemic vasculitis that affects both small and medium-sized vessels. Patients typically initially suffer from a limited form that may consist of constitutional symptoms and localized manifestations such as chronic sinusitis, rhinitis, otitis media, ocular conditions. In later stages, more serious manifestations may arise, including pulmonary complications and glomerulonephritis, although the skin, eyes, and heart may also be involved but these lesions are less common. Diagnosis is based on laboratory testing (positive for PR3-ANCA/c-ANCA), imaging, and biopsy of affected organs, which demonstrate necrotizing granulomatous inflammation. GPA is treated with immunosuppressive drugs, typically consisting of glucocorticoids combined with methotrexate, cyclophosphamide, or rituximab. Relapses are common and the following systems are affected: Lower respiratory tract (95% of cases), renal involvement (80% of cases), skin lesions (45% of cases), ocular involvement (45% of cases) and cardiac involvement (33% of cases).
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 56
Incorrect
-
The lamina propria contains all of the following except:
Your Answer:
Correct Answer: Neutrophils
Explanation:The connective tissue of the lamina propria is very loose, allowing it to be very cell rich. The cell population of the lamina propria is variable and can include, for example, fibroblasts, lymphocytes, plasma cells, macrophages, eosinophilic leukocytes, and mast cells. It provides support and nutrition to the epithelium, as well as the means to bind to the underlying tissue.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 57
Incorrect
-
The Wiebel-Palade body found in the endothelial cells is responsible for the production and release of which factor?
Your Answer:
Correct Answer: Von Willebrand factor
Explanation:Weibel-Palade bodies are the storage granules of endothelial cells, the cells that form the inner lining of the blood vessels and heart. They store and release two principal molecules, von Willebrand factor and P-selectin, and thus play a dual role in haemostasis and inflammation.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 58
Incorrect
-
The basic unit of contraction in myocytes is:
Your Answer:
Correct Answer: Sarcomere
Explanation:Sarcomere is the organelle where calcium is stored to be released during contraction of the muscle. It is the basic unit of contraction in striated muscle fibers. As myocytes are also striated muscles, sarcomeres also forms the basic unit of contraction. The impulses travel along the membrane and via its interaction with the dihydropyridine receptors it releases the stored calcium.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 59
Incorrect
-
A 35-year-old male was brought to you in a confused state. Although not your patient, you can make out that the man has a history of schizophrenia, and has recently had his medications altered. Clinically, you find evidence of a lower respiratory tract infection, and blood investigations indicate a neutropenic picture.What is the most likely drug causing the neutropenia?
Your Answer:
Correct Answer: Clozapine
Explanation:Clozapine can cause neutropenia or agranulocytosis.Clozapine is an atypical antipsychotic used in the treatment of schizophrenia, and in patients who are intolerant to, or unresponsive to other antipsychotics. It is a weak D2-receptor and D1-receptor blocking activity, with noradrenolytic, anticholinergic, and antihistaminic properties.Many antipsychotic drugs can occasionally cause bone marrow depression, but agranulocytosis is particularly associated with clozapine.Other side effects include:Hypotension, tachycardiaFever, sedation, seizures (with high doses)Appetite increaseConstipationHeartburnWeight gainExtrapyramidal symptomsAgranulocytosisNeuroleptic malignant syndrome
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 60
Incorrect
-
Afferent A Ī“ fibers from nociceptors terminate primarily on neurons in which lamina:
Your Answer:
Correct Answer: I and V
Explanation:Nociceptors are receptors of pain sensation. There are 2 primary afferent/sensory pain fibers which transmit impulses from the receptor to the CNS, specifically to the dorsal horn of the spinal cord. The two fibers are A Ī“ and C fibers. The dorsal horn of the spinal cord is the relay centre for sensory information converging from the periphery. Grey matter of the dorsal horn is subdivided in to laminae based on cytoarchitecture. C fibers terminate in lamina II the substantia gelatinosa. A Ī“ fibers terminate primarily in lamina I but some project more deeply to terminate in lamina V.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 61
Incorrect
-
The proportion of individuals within a population affected by disease at a specific time point, based on positive testing for serum antibodies is known as:
Your Answer:
Correct Answer: Sero-Prevalence
Explanation:In immunology, seroconversion is the time period during which a specific antibody develops and becomes detectable in the blood. After seroconversion has occurred, the disease can be detected in blood tests for the antibody. Sero-prevalence includes individuals who are antibody positive for a specific infection at a specific point in time.
-
This question is part of the following fields:
- Infectious Diseases
- Medicine
-
-
Question 62
Incorrect
-
Interruption of the left optic tract will result in which visual field defect?
Your Answer:
Correct Answer: Right homonymous hemianopia
Explanation:Right homonymous hemianopia is due to a lesion or pressure on the left optic tract. Total blindness of the left eye is due to a complete occlusion of the left optic nerve. Bipolar hemianopia is due to a midline chiasmal lesion. Left nasal hemianopia due to a lesion involving the left perichiasmal area. Right homonymous inferior quadrantanopia is due to involvement of the lower left optic radiations.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 63
Incorrect
-
The main source of nutrients in the liver is via the
Your Answer:
Correct Answer: Portal vein
Explanation:The portal vein or hepatic portal vein is a blood vessel that carries blood from the gastrointestinal tract and spleen to the liver. This blood is rich in nutrients that have been extracted from food, and the liver processes these nutrients; it also filters toxins that may have been ingested with the food. 75% of total liver blood flow is through the portal vein, with the remainder coming from the hepatic artery proper.
-
This question is part of the following fields:
- Hepatobiliary
- Medicine
-
-
Question 64
Incorrect
-
Question 65
Incorrect
-
Which of the following components regulate cardiac output?
Your Answer:
Correct Answer: All of the above
Explanation:Cardiac output is regulated by the autonomic nervous system with sympathetic nerves having a positive chronotropic and inotropic effect and parasympathetic nerves having the opposite effect. An increase in preload will increase cardiac output likewise an afterload increase will also increase cardiac output.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 66
Incorrect
-
Dicrotic notch is produced by which valves?
Your Answer:
Correct Answer: Aortic
Explanation:The graph of aortic pressure throughout the cardiac cycle displays a small dip (the incisure or dicrotic notch) which coincides with the aortic valve closure. The dip in the graph is immediately followed by a brief rise (the dicrotic wave) then gradual decline.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 67
Incorrect
-
Which statement is correct about the clinical state of methemoglobinemia?
Your Answer:
Correct Answer: May arise due to a hereditary deficiency of NADH.
Explanation:Methaemoglobin is a form of haemoglobin that contains ferric [Fe3+] iron and has a decreased ability to bind oxygen. Spontaneously formed methaemoglobin is normally reduced by protective enzyme systems, e.g., NADH methaemoglobin reductase, hence a deficiency of NADH may result in increased levels of methaemoglobin
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 68
Incorrect
-
Which receptor type is associated with uterine contracture in pregnancy?
Your Answer:
Correct Answer: Ī1
Explanation:Alpha-1 adrenergic receptors cause uterine contraction during pregnancy. They are linked to Gq-proteins that activate smooth muscle contraction through the IP3 signal transduction pathway.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 69
Incorrect
-
The midbrain, medulla and pons, contain the following cranial nerve nuclei?
Your Answer:
Correct Answer: CN 3 - 12
Explanation:The cranial nerves (with the exception of I and II) originate in the brainstem, which includes theĀ midbrain, theĀ pons, and theĀ medulla.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 70
Incorrect
-
The T-tubular system in cardiac muscle is:
Your Answer:
Correct Answer: Transmits action potential from sarcolemma to the SR to allow for Ca2+ release into the cytoplasm
Explanation:Action potentials are transmitted to the fibrils of a fiber through the T tubule system. It triggers the release of Ca 2+ from the terminal cisterns. Depolarization of the T tubules activates the sarcoplasmic reticulum through the dihydropyridine receptors, which are voltage gated calcium channels.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 71
Incorrect
-
Which one of the following diuretics is associated with metabolic acidosis?
Your Answer:
Correct Answer: Acetazolamide
Explanation:Acetazolamide is in the diuretic and carbonic anhydrase inhibitor families of medication. It works by decreasing the amount of hydrogen ions and bicarbonate in the body and can thus cause metabolic acidosis and electrolyte changes (hypokalaemia, hyponatremia).
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 72
Incorrect
-
Which of the following skin coloration abnormalities occurs due to adrenal insufficiency due to primary adrenal disease?
Your Answer:
Correct Answer: Hyperpigmentation
Explanation:Addison’s disease, also known as primary adrenal insufficiency, or hypocortisolism is an endocrine disorder. Hyperpigmentation is one of its most common signs; it occurs as a result of an increase in pro-opiomelanocortin to produce more ACTH in response to the decreased levels of cortisol. Pro-opiomelanocortin is a precursor of melanocyte stimulating hormone (MSH), which stimulates melanocytes, causing darkening of the skin.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 73
Incorrect
-
The primary sensory cortex is:
Your Answer:
Correct Answer: Brodmann area 3,1,2
Explanation:A Brodmann area in the brain is defined by cytoarchitecture, histology and organization of cells:Primary somatosensory cortex is areas 3,1, and 2Primary Motor 4Premotor 6Primary Visual 17Primary Auditory 41Brocas 44
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 74
Incorrect
-
The ependyma fuse with which of the following to from the choroid plexus?
Your Answer:
Correct Answer: Tela choroidea
Explanation:The choroid plexus produces the cerebrospinal fluid (CSF) in the ventricles of the brain. It consists of modified ependymal cells. Tela choroidea is a region of pia mater of the meninges and underlying ependyma thatās a part of the choroid plexus. It is a very thin layer of the connective tissue of pia mater that overlies and covers the ependyma.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 75
Incorrect
-
90% of erythropoietin necessary for haemopoesis is produced by the kidneys, the remainder is formed in the?
Your Answer:
Correct Answer: Liver
Explanation:Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with peritubular capillary and proximal convoluted tubule. It is also produced in perisinusoidal cells in the liver. While liver production predominates in the fetal and perinatal period, renal production is predominant during adulthood.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 76
Incorrect
-
In adults, the major site of haematopoiesis is?
Your Answer:
Correct Answer: The axial skeleton
Explanation:Bone marrow is the flexible tissue in the interior of bones. In humans, red blood cells are produced by cores of bone marrow in the heads of long bones.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 77
Incorrect
-
Question 78
Incorrect
-
In terms of relative steroid potency, how much prednisone is equivalent to 100mg hydrocortisone?
Your Answer:
Correct Answer: 25mg
Explanation:Different corticosteroids have varying degrees of potency. 1 mg of prednisone is equivalent to 4 mg of hydrocortisone. Therefore, 25 mg of prednisone are equivalent to 100 mg of hydrocortisone.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 79
Incorrect
-
Which statement is incorrect regarding transcription of DNA?
Your Answer:
Correct Answer: A gene is always read in the 3ā-5ā orientation and at 3ā promoter sites.
Explanation:In both prokaryotes and eukaryotes RNA polymerase acts in the 5′-3′ direction and hence the RNA is transcribed in this direction. The mRNA produced is immature as it has introns as well as exons presents. It undergoes a process known as splicing to remove the exons and then interacts with the ribosomes to form proteins.
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 80
Incorrect
-
Which part of the cerebellum is primarily responsible for interacting with the motor cortex and planning and programming movements?
Your Answer:
Correct Answer: Cerebrocerebellum
Explanation:The cerebrocerebellum is the largest functional subdivision of the cerebellum, comprising of theĀ lateral hemispheresĀ and theĀ dentateĀ nuclei. It is involved in the planning and timing of movements, and in the cognitive functions of the cerebellum.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 81
Incorrect
-
On which presynaptic receptor does noradrenalin act to inhibit noradrenalin secretion?
Your Answer:
Correct Answer: Ī2 receptor
Explanation:Adregenic receptors are A1, A2, B1, B2, B3. Out of these, the function of the A2 receptor is inhibition of transmitter release including nor adrenalin and acetylcholine of the autonomic nervous system.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 82
Incorrect
-
The thalamic nuclei that project over wide regions of the neocortex are:
Your Answer:
Correct Answer: Specific relay nuclei
Explanation:The thalamus is considered the relay station for sensory and motor stimuli. There are three basic types of thalamic nuclei: relay nuclei, association nuclei and non-specific nuclei. Relay nuclei receive very well defined inputs and project this signal to functionally distinct areas of the cerebral cortex. These include the nuclei that relay primary sensations and also the nuclei involved in feedback of cerebellar signals and basal gangliar output.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 83
Incorrect
-
Calcium needed for cardiac muscle contraction is made available during which phase of the action potential?
Your Answer:
Correct Answer: 2
Explanation:It is made available during the plateau phase of the action potential i.e. phase 2. During the plateau phase of the action potential, Calcium from the extracellular fluid enters through the L type of calcium channels. This entry triggers the release of more calcium from the sarcoplasmic reticulum via the ryanodine receptors.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 84
Incorrect
-
A 62 year old female complains of pain and stiffness in her shoulders. She also finds it difficult to get out of her chair. From the list of symptoms below, choose the one most likely to support the diagnosis of polymyalgia rheumatica.
Your Answer:
Correct Answer: Low grade fever
Explanation:Polymyalgia rheumatica is an inflammatory disease which usually causes stiffness and pain in the shoulder – this can also occur in the pelvic girdle muscles. Its onset can either be subacute or acute and is associated with a systemic inflammatory response. This, therefore, causes symptoms such as fever, weight loss, anorexia, and malaise. Polymyalgia rheumatica is unpredictable in its course and it is known that 30 per cent of patients also present with giant cell arteritis. The cause of this disease is unknown but studies have shown it have infectious origins. Diagnosis of polymyalgia rheumatica can be difficult and other inflammatory diseases have to be excluded first. Patients with this disease are usually over 60 years of age (it is very rarely seen in those under 50). Muscle weakness does not present, although this can be hard to assess when the patient is in pain. Low-grade fever and weight loss are typical of this disease due to chronic inflammation. As such, weight gain is very rare and peripheral joints are usually not affected (they can be affected but it is very rare). Also, muscle tenderness is not a specific symptom of the disease – it is therefore not a classical finding of polymyalgia rheumatica. Although patients usually complain of stiffness and pain, the muscles are usually not significantly tender – this is usually more associated with fibromyalgia or myositis. When investigated, a normochromic/normocytic anaemia; a raised erythrocyte sedimentation rate often over 50 mm/hr., and raised C reactive protein are usually revealed. Symptoms of giant cell arteritis should also be sought, such as headaches, visual disturbances, TIAs (transient ischemic attacks), jaw claudication, and thickened temporal arteries. The patient response to a moderate dose of steroids is useful when confirming a diagnosis of polymyalgia rheumatica. The maximum dose of prednisolone should not exceed 20mg once a day. After treatment, patients should show a 70 per cent improvement in symptoms within a month (between 3-4 weeks). Inflammatory markers should also fall back to their normal levels. Non-steroidal anti-inflammatories are of little use and are associated with morbidity. There is also little evidence for the use of steroidal-sparing agents.
-
This question is part of the following fields:
- Geriatrics
- Medicine
-
-
Question 85
Incorrect
-
A 39 year old woman with a history of rheumatoid arthritis has recently been switched from methotrexate to leflunomide. Monitoring of full blood count and LFTs has been carried out. Which of the following parameters should also be monitored in this case?
Your Answer:
Correct Answer: Blood pressure
Explanation:Blood pressure should be routinely measured as leflunomide may cause hypertension and thus an increase in BP. It doesnāt cause changes in blood sugar levels, peak expiratory flow rate or haematuria.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 86
Incorrect
-
Where does the anterior pituitary receive most of its blood supply?
Your Answer:
Correct Answer: Portal hypophysial vessels
Explanation:The anterior pituitary receives its arterial supply from the superior hypophyseal artery, which is a branch of the internal carotid that forms a capillary around the hypothalamus; thus forming the hypothalamo-hypophysial portal system.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 87
Incorrect
-
Select the correct statement regarding cholecystokinin (CCK):
Your Answer:
Correct Answer: It causes gallbladder contraction and pancreatic enzyme secretion.
Explanation:CCK has a primary action of increasing the motility of the gallbladder by contracting the muscles in the mucosa of the gall bladder. Apart from this, it augments the action of secretin, resulting in the production of an alkaline pancreatic juice. It increases the synthesis of enterokinase, inhibits gastric emptying and may also enhance the motility of the small intestine and colon. It is released (secreted) by your small intestine during the digestive process. It’s sometimes called pancreozymin.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 88
Incorrect
-
Depolarization spreads rapidly through cardiac muscle fibers because of the presence of:
Your Answer:
Correct Answer: Gap junctions
Explanation:The cardiac muscles have gap junctions in between the cells. They allow for the formation of low resistance passages, which allow ions to diffuse through every muscle fiber rapidly and result in the cardiac muscles functioning as a syncytium, without any protoplasmic bridges involved.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 89
Incorrect
-
Where in the course of the gastrointestinal tract does the first significant digestion of fat begin in a normal human being?
Your Answer:
Correct Answer: Duodenum
Explanation:The enzyme lipase which is responsible for digestion of fat is secreted by the exocrine pancreas in the 2nd part of the duodenum at the point where the pancreatic duct opens. It opens together with the common bile duct which contains bile that emulsify fat aiding in digestion. The oesophagus, stomach and mouth do not contain enzymes related to fat digestion.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 90
Incorrect
-
The outer and inner surfaces of the arachnoid mater is covered with:
Your Answer:
Correct Answer: Mesothelial cells
Explanation:The arachnoid mater is one of the three meninges that covers the brain and spinal cord. It is interposed between the two other meninges, the more superficial and much thicker dura mater and the deeper pia mater, from which it is separated by the subarachnoid space. The arachnoid mater consists of a subdural mesothelial layer and a compact central layer
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 91
Incorrect
-
Glucose is typically removed from the urine byā¦?
Your Answer:
Correct Answer: Secondary active transport
Explanation:Glucose, amino acids, inorganic phosphate, and some other solutes are resorbed via secondary active transport through co-transporters driven by the sodium gradient out of the nephron.
-
This question is part of the following fields:
- Medicine
- Renal
-
-
Question 92
Incorrect
-
A 35-year-old woman under treatment for long-term epilepsy with valproate presented with complaints of excessive weight gain. She is consuming oral contraceptive pills.Which among the following is the best alternative to valproate for treating long-term epilepsy?
Your Answer:
Correct Answer: Lamotrigine
Explanation:Among the given anti-epileptics the best drug that can be given in this patient is lamotrigine.Topiramate, carbamazepine, phenytoin, and phenobarbital are all hepatic enzyme inducers and are associated with decreased effectiveness of the oral contraceptive (OCP) due to acceleration of the metabolism of oestrogens and progestogens.If she is planning on pregnancy then registry studies suggest that lamotrigine would also be the best choice.Other hepatic enzyme inducers include rifampicin, spironolactone, griseofulvin, etc.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 93
Incorrect
-
Which of the following is a product of D cells
Your Answer:
Correct Answer: Somatostatin
Explanation:Somatostatin is secreted by D cells, HCL and intrinsic factor secreted by parietal cells. Trefoil peptides are secreted by mucus secreting goblet cells and gastrin releasing peptide (grp) by post-ganglionic fibers of the vagus nerve (which innervate the G cells of the stomach).
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 94
Incorrect
-
A 56-year-old male presents to the emergency department with confusion and agitation for the past four hours. He is a known alcoholic who has abstained from drinking for the past three days.On examination, he is sweating, agitated and disorientated. His temperature is 37.7Ā°C, pulse 112 bpm regular and blood pressure is 150/76 mmHg. Blood investigations performed in the emergency department reveal:FBC: NormalU&E: NormalPlasma glucose: 4.6 mmol/l (3.6-6)Which of the following medications would be the most appropriate treatment for this man?
Your Answer:
Correct Answer: Oral lorazepam
Explanation:The most probable diagnosis for this patient is delirium tremens due to alcohol withdrawal, which should be treated as a medical emergency.Ā Delirium tremens is a hyperadrenergic state and is often associated with tachycardia, hyperthermia, hypertension, tachypnoea, tremor, and mydriasis.Treatment:- The most common and validated treatment for alcohol withdrawal is benzodiazepine: first-line treatment includes oral lorazepam. – If the symptoms persist, or the medication is refused, parenteral lorazepam, haloperidol or olanzapine should be given.- Central-acting, alpha-2 agonists such as clonidine and dexmedetomidine should not be used alone for the treatment of alcohol withdrawal.- It is also recommended to avoid using alcohol, antipsychotics, anticonvulsants, beta-adrenergic receptor blockers, and baclofen for the treatment of alcohol withdrawal as there are not enough studies to support the safety of these.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 95
Incorrect
-
Ventricular depolarization plus ventricular repolarization is shown by the _____ interval
Your Answer:
Correct Answer: QT
Explanation:The QT interval represents ventricular depolarization as well as ventricular repolarization.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 96
Incorrect
-
A 32 year old female is diagnosed with SLE based on her complaints of polyarthralgia, mouth ulcers and ANA positivity. Labs reveal normal urinalysis, urea and electrolytes. ESR is 90mm in the first hour. How will you manage this patient?
Your Answer:
Correct Answer: Hydroxychloroquine 200 mg/day
Explanation:Hydroxychloroquine is used in the management of SLE as it prevents disease progression and has relatively mild side effects, for instance headache, nausea etc. Its use reduces the usage of corticosteroids. It is particularly effective when the disease is less severe and there is no organ involvement. Cyclophosphamide and prednisolone are indicated in cases of renal, neurological and lung involvement.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 97
Incorrect
-
A 32 year old woman presents with a painful elbow which she has been feeling for the past two weeks. Which of the following will be consistent with a diagnosis of tennis elbow?
Your Answer:
Correct Answer: Pain on wrist extension against resistance
Explanation:Lateral epicondylitis (tennis elbow) is an overuse injury of the hand and finger extensor tendons that originate in the lateral humeral epicondyle that occurs following repeated or excessive pronation/supination and extension of the wrist (e.g., in racquet sports). Clinical features include pain and tenderness over the lateral epicondyle and along extensor muscles and thickening of the tendons. The examiner holds the patient’s hand with the thumb placed over the lateral epicondyle – The patient makes a fist, supinates the forearm, deviates radially, and extends the fist against the examiner’s resistance which will result in pain over the lateral epicondyle. Conservative treatment includes rest, physiotherapy and orthotic braces. If this fails corticosteroids and lidocaine injections are employed. Surgery is indicated in patients with persistent symptoms despite 6 months of conservative treatment. Excision of abnormal tendon tissue; longitudinal incisions (tenotomies) in scarred and fibrotic areas to promote healing.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 98
Incorrect
-
AV valves open during?
Your Answer:
Correct Answer: Early diastole
Explanation:The cardiac cycle refers to a complete heartbeat from its generation to the beginning of the next beat, and so includes the diastole, the systole, and the intervening pause.The first stage, diastole, is when the semilunar valves (the pulmonary valve and the aortic valve) close, the atrioventricular (AV) valves (the mitral valve and the tricuspid valve) open, and the whole heart is relaxed. The second stage, atrial systole, is when the atrium contracts, and blood flows from atrium to the ventricle.The third stage, isovolumic contraction is when the ventricles begin to contract, the AV and semilunar valves close, and there is no change in volume. The fourth stage, ventricular ejection, is when the ventricles are contracting and emptying, and the semilunar valves are open. During the fifth stage, isovolumic relaxation time, pressure decreases, no blood enters the ventricles, the ventricles stop contracting and begin to relax, and the semilunar valves close due to the pressure of blood in the aorta.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 99
Incorrect
-
Which one of the following conditions is least likely to be associated with pyoderma gangrenosum?
Your Answer:
Correct Answer: Syphilis
Explanation:The following are conditions commonly associated with pyoderma gangrenosum:
Inflammatory bowel disease:
- Ulcerative colitis
- Crohn’s disease
Arthritides:
- Rheumatoid arthritis
- Seronegative arthritis
Haematological disease:
- Myelocytic leukaemia
- Hairy cell leukaemia
- Myelofibrosis
- Myeloid metaplasia
- Monoclonal gammopathy
Autoinflammatory disease:
- Pyogenic sterile arthritis, pyoderma gangrenosum, and acne syndrome (PAPA syndrome)
- Granulomatosis with polyangiitis
-
This question is part of the following fields:
- Dermatology
- Medicine
-
-
Question 100
Incorrect
-
Why does arterial blood pressure drop during pregnancy?
Your Answer:
Correct Answer: Progesterone relaxes vascular smooth muscle
Explanation:Progesterone relaxes vascular smooth muscle thus resulting In a decrease in total peripheral resistance. This accounts for the increase in the cardiac output.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 101
Incorrect
-
Inactive cellular marrow is called
Your Answer:
Correct Answer: Yellow marrow
Explanation:The two types of bone marrow are red marrow, which consists mainly of hematopoietic tissue, and yellow marrow, which is mainly made up of fat cells.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 102
Incorrect
-
Absolute refractory period in a cardiac action potential graph occurs during.
Your Answer:
Correct Answer: All of the above
Explanation:Absolute refractory period (ARP): the cell is completely unexcitable to a new stimulus and occurs from phase 0 – 2 i.e. depolarisation, early repolarisation and plateau phase.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 103
Incorrect
-
Question 104
Incorrect
-
When observing a JVP, which of the following would lead to prominent v waves?
Your Answer:
Correct Answer: Tricuspid regurgitation
Explanation:The v wave corresponds to Venous filling when the tricuspid valve is closed and venous pressure increases from venous return. In Tricuspid regurgitation there is additional blood from the regurgitant flow and thus this leads to a more prominent V wave.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 105
Incorrect
-
Which one of the following is a cause of a soft second heart sound?
Your Answer:
Correct Answer: Aortic stenosis
Explanation:Second heart sound (S2) forms the dub of lub-dub and is composed of components A2 and P2. ā¢Ā Ā Ā loud: hypertensionā¢Ā Ā Ā soft: ASā¢Ā Ā Ā fixed split: physiological split (normally occurs during inhalation), right bundle branch block, pulmonary stenosis, and atrial septal defect.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 106
Incorrect
-
The conversion of fructose to fructose 1-phosphate is catalysed by:
Your Answer:
Correct Answer: Fructokinase
Explanation:The first step in the metabolism of fructose is the phosphorylation of fructose to fructose 1-phosphate by fructokinase.
-
This question is part of the following fields:
- Medicine
- Metabolism
-
-
Question 107
Incorrect
-
Which receptor type is associated with the inhibition of pancreatic endocrine secretion?
Your Answer:
Correct Answer: Ī2
Explanation:The activation of alpha 2-adrenergic receptors in pancreatic beta-cells works by inhibiting the secretion of insulin.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 108
Incorrect
-
Cell membrane proteins may act as:
Your Answer:
Correct Answer: All of the options
Explanation:Membrane proteins perform a variety of functions including:Membrane receptor proteins relay or carry signals between the cell’s internal and external environments.Transport proteins move molecules and ions (ionic channels) across the membrane. Membrane enzymes may have many activities, such as oxidoreductase, transferase or hydrolase andCell adhesion molecules
-
This question is part of the following fields:
- Cell Biology
- Medicine
-
-
Question 109
Incorrect
-
The ācā wave in JVP corresponds more closely with:
Your Answer:
Correct Answer: Isovolumetric contraction
Explanation:The jugular venous pressure (JVP, sometimes referred to as jugular venous pulse) is the indirectly observed pressure over the venous system via visualization of the internal jugular vein. It can be useful in the differentiation of different forms of heart and lung disease. Classically three upward deflections (peaks) and two downward deflections (troughs) have been described:The upward deflections are the a (atrial contraction), c (ventricular contraction and resulting bulging of tricuspid into the right atrium during isovolumetric systole) and v = venous filling.The downward deflections of the wave are the x (the atrium relaxes and the tricuspid valve moves downward) and the y descent (filling of ventricle after tricuspid opening).
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 110
Incorrect
-
Stem cell characteristics include the following except
Your Answer:
Correct Answer: Differentiation and proliferation into progenitor cells committed to multiple cell lines
Explanation:The classical definition of a stem cell requires that it possess two properties:Self-renewal: the ability to go through numerous cycles of cell division while maintaining the undifferentiated state.Potency: the capacity to differentiate into specialized cell types. In the strictest sense, this requires stem cells to be either totipotent or pluripotent to be able to give rise to any mature cell type
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 111
Incorrect
-
Which neurotransmitter is released from the postganglionic fibers in the sympathetic division?
Your Answer:
Correct Answer: Noradrenalin
Explanation:Noradrenalin Is the neurotransmitter that is released from the postganglionic fibers of the sympathetic division. It is stored in granules at the sympathetic knobs. It Is a methyl derivative.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 112
Incorrect
-
In the presence of oxygen , lactate that was produced under anaerobic conditions is converted to:
Your Answer:
Correct Answer: Pyruvate
Explanation:Lactate can be used in two ways:Oxidation back to pyruvate by well-oxygenated muscle cells, heart cells, and brain cells. Pyruvate is then directly used to fuel the Krebs cycle orConversion to glucose via gluconeogenesis in the liver and release back into circulation.
-
This question is part of the following fields:
- Cell Biology
- Medicine
-
-
Question 113
Incorrect
-
Endothelial cells are attached to adjacent cells by adherent junctions via:
Your Answer:
Correct Answer: Cadherins
Explanation:Cadherins are calcium dependant molecules that mediate cell to cell adhesions in epithelial and endothelial cells among others.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 114
Incorrect
-
A study is developed to look at the potential of hip protectors to reduce femoral neck fractures in elderly nursing home patients. The study included 800 patients randomly selected with an average age of 82 years of age. The data was collected over a two year period and the patients were randomly put in the standard care group or the hip protector group. From the 400 patients assigned to the hip protector group, 10 had a femoral neck fracture over the two year period. From the 400 patients assigned to the standard care group, 20 had a femoral neck fracture over the two year period. What is the correct value regarding the absolute risk reduction?
Your Answer:
Correct Answer: 0.025
Explanation:Absolute risk reduction (ARR) ā also called risk difference (RD) ā is the most useful way of presenting research results to help your decision-making. In this example, the ARR is 8 per cent (20 per cent – 12 per cent = 8 per cent). This means that, if 100 children were treated, 8 would be prevented from developing bad outcomes. Another way of expressing this is the number needed to treat (NNT). If 8 children out of 100 benefit from treatment, the NNT for one child to benefit is about 13 (100 Ć· 8 = 12.5). CER = 20 / 400 = 1 / 20 = 0.05, EER = 10 / 400 = 0.025, ARR =CER – EER = 0.025
-
This question is part of the following fields:
- Medicine
- Research Skills
-
-
Question 115
Incorrect
-
A 24-year-old student is brought to A&E having ingested at least 20 tablets of paracetamol 8 hours earlier. She weighs 61kg. What should her immediate management consist of?
Your Answer:
Correct Answer: Intravenous N-acetylcysteine
Explanation:Activated charcoal is useful if given within one hour of the paracetamol overdose. Liver function tests, INR and prothrombin time will be normal, as liver damage may not manifest until 24 hours or more after ingestion. The antidote of choice is intravenous N-acetylcysteine, which provides complete protection against toxicity if given within 10 hours of the overdose.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 116
Incorrect
-
An 82 year old male woke up experiencing incoherent speech - he is also finding it difficult to find the right words to explain his thoughts. Doctors have examined him, and everything else appears to be normal. They have also found that his comprehension is good. From the list of options, choose the anatomical site which in this instance, is most likely affected.
Your Answer:
Correct Answer: Brocaās Area
Explanation:The combination of good comprehension but poor speech quality in this patient is consistent with damage to the Broca’s area. The Wernicke’s area is responsible for the understanding of speech, and so is not consistent with this patient.
-
This question is part of the following fields:
- Geriatrics
- Medicine
-
-
Question 117
Incorrect
-
Where is the aqueous humor normally reabsorbed?
Your Answer:
Correct Answer: Canal of schlemm
Explanation:Aqueous humor is a clear protein free fluid secreted by the ciliary body, it travels to the anterior chamber through the pupil and is absorbed through a network of trabeculae into the canal of schlemm
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 118
Incorrect
-
Which of the following is false with regard to the following statement: Proto- oncogenes can be transformed to oncogenes in the following ways.
Your Answer:
Correct Answer: Inhibition of P53
Explanation:Proto oncogenes cannot be transformed into oncogenes due to inhibition of P53 gene. There has to be a mutation in the proto oncogene. All the other options are true.
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 119
Incorrect
-
Calcium is transported over the brush border in the gut, via which transporter / channel?
Your Answer:
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 120
Incorrect
-
A 30-year-old male with a history of premature cardiovascular disease in the family has come for review of his lab investigations. His fasting cholesterol is 8.4 mmol/l with high-density lipoprotein (HDL) of 1.6 mmol/l. You elect to commence him on atorvastatin 20 mg PO daily.Which of the following best describes the mechanism of action of the statins?
Your Answer:
Correct Answer: They inhibit HMG CoA reductase
Explanation:Statins are a selective, competitive inhibitor of hydroxymethylglutaryl-CoA (HMG-CoA) reductase, which is the enzyme responsible for the conversion of HMG-CoA to mevalonate in the cholesterol synthesis pathway.Statins are usually well tolerated with myopathy, rhabdomyolysis, hepatotoxicity, and diabetes mellitus being the most common adverse reactions. This is the rate-limiting step in cholesterol synthesis, that leads to increased hepatic low-density lipoprotein (LDL) receptors and reduced hepatic VLDL synthesis coupled with increased very-low-density lipoprotein (VLDL) clearance.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 121
Incorrect
-
Which one of the following is able to move across cell membranes by passive diffusion?
Your Answer:
Correct Answer: CO2
Explanation:The cell membrane is permeable to water molecules and a few other small, uncharged, molecules like oxygen (O2) and carbon dioxide (CO2). Larger molecules like glucose or charged ions are unable to cross passively.
-
This question is part of the following fields:
- Cell Biology
- Medicine
-
-
Question 122
Incorrect
-
Which of the following is not innervated by the parasympathetic nerve supply?
Your Answer:
Correct Answer: Radial muscle of iris
Explanation:The sphincter pupillae is supplied by the parasympathetic fibers from the Edinger Westphal nucleus of the oculomotor nerve. The dilator pupillae (radial muscle) is supplied by the postganglionic fibers of the superior cervical sympathetic ganglion. The parasympathetic nerve supply to the salivary glands originate in the parasympathetic nucleus of the facial nerve (superior salivatory nucleus) and the glossopharyngeal nerve (inferior salivatory nucleus). The parasympathetic preganglionic fibers originate in the dorsal nucleus of the vagus nerve and descend into the thorax in the vagus nerve. The fibers terminate by synapsing with postganglionic neurons in the cardiac plexuses. Postganglionic fibers terminate on the sinoatrial and atrioventricular nodes and on the coronary arteries Parasympathetic supply to the stomach is via the vagus nerve.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 123
Incorrect
-
With regard to the cell membrane:
Your Answer:
Correct Answer: It consists of an outer hydrophilic & an inner hydrophobic layer
Explanation:The cell membrane consists primarily of a thin layer of amphipathic phospholipids that spontaneously arrange with the hydrophobic tail regions on the inside and the hydrophilic head regions outside. Membranes typically have a large content of proteins, around 50% of membrane volume.
-
This question is part of the following fields:
- Cell Biology
- Medicine
-
-
Question 124
Incorrect
-
Which vitamin plays a major role in the metabolism of many amino acids?
Your Answer:
Correct Answer: Vitamin B6
Explanation:Vitamin B6 is part of the vitamin B group, and its active form, pyridoxal 5ā²-phosphate (PLP) serves as a coenzyme in many enzyme reactions in amino acid, glucose, and lipid metabolism.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 125
Incorrect
-
Choose the correct answer: fibers in the superior cerebellar peduncle:
Your Answer:
Correct Answer: Are mainly ventral spinocerebellar tracts from the cerebellar nuclei to the thalamus and red nucleus
Explanation:There are three cerebellar peduncles with different connections and functions. The three are mainly, superior, middle and inferior. The superior cerebellar peduncle is also known as the āBrachium conjunctivumā. It predominantly contains efferent fibers from the cerebellar nuclei, as well as some afferents from the spinocerebellar tract. The efferent pathways include cerebellorubral, dentatothalamic, and fastigioreticular fibers. These are tracts projecting from the deep cerebellar nuclei to the thalamus and red nucleus. The middle cerebellar peduncle connects to the pontine nucleus and the dorsal spinocerebellar tracts run through the superior cerebellar peduncle.
The superior cerebellar peduncle contains vital afferent and efferent fibers includingĀ cerebellothalamic, cerebellorubral and ventrospinocerebellar tracts.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 126
Incorrect
-
A 50-year-old woman diagnosed with non-Hodgkin's Lymphoma is about to be started on the CHOP regimen (cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisolone). Her pre-chemotherapy blood investigations show:Hb: 11.8 g/dlPlatelets: 423 x 109/lWBC: 11.2 x 109/lNa+: 143 mmol/lK+: 3.9 mmol/lUrea: 6.2 mmol/lCreatinine: 78 Ī¼mol/lUric acid: 0.45 mmol/lCiprofloxacin is prescribed in addition to the CHOP regimen to reduce the risk of neutropenic sepsis. Which of the following drugs should be added to lower the risk of other complications?
Your Answer:
Correct Answer: Allopurinol
Explanation:Tumour lysis syndrome (TLS) occurs most notably in patients with haematological malignancies including, Non-Hodgkinās Lymphoma (NHL) and Acute Lymphocytic Leukaemia (ALL).Risk factors for TLS include:ā¢ Large tumour burdenā¢ Sensitivity of the tumour to chemotherapyā¢ Rapid tumour growth rateTLS is characterized by:ā¢ Hyperuricemiaā¢ Hyperkalaemiaā¢ Hyperphosphatemiaā¢ HypocalcaemiaTreatment of TLS:ā¢ Allopurinol: It is a xanthine oxidase inhibitor, it reduces the conversion of nucleic acid by-products to uric acid. Thus, it prevents urate nephropathy and subsequent oliguric renal failure. Note: dose reduction is essential in renal failure or if given along with mercaptopurine or azathioprine.Alternatives to Allopurinol: Febuxostat; Rasburicase are useful in patients with hyperuricemia.ā¢ Hydrationā¢ Diuresis: Should be considered in well hydrated patients with insufficient urine output. Furosemide to be considered in normo-volemic patients with hyperkalaemia. Urine alkalization can be considered for promoting alkaline diuresis.ā¢ Treatment of electrolyte imbalances including hyperkalaemia, hyperphosphatemia, and hypocalcaemia.ā¢ Dialysis can be considered in refractory cases.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 127
Incorrect
-
Concerning coronary arteries, what is the net effect of B2 stimulation on the heart (e.g. Running athlete)?
Your Answer:
Correct Answer: Vasodilation via production of metabolites
Explanation:The coronary arterioles contain Ī±-adrenergic receptors, which cause vasoconstriction, and Ī²-adrenergic receptors, which cause vasodilation. Activity in the noradrenergic nerves to the heart and injections of norepinephrine cause coronary vasodilation. However, norepinephrine also increases the heart rate and the force of cardiac contraction, and the vasodilation is due to production of vasodilator metabolites in the myocardium secondary to the increase in its activity. As exercise has the same effect as sympathetic stimulation, it will result in vasodilation.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 128
Incorrect
-
In the functional unit of the liver (acinus), the oxygenationā¦
Your Answer:
Correct Answer: Reduces towards the centre
Explanation:Cells located close to the portal triad or peripheral zone which consist of arterioles from the hepatic artery are the most oxygenated cells. Cells in the central zone are least oxygenated and mainly receive blood supply from the central vein which is a branch of the hepatic vein.
-
This question is part of the following fields:
- Hepatobiliary
- Medicine
-
-
Question 129
Incorrect
-
Which hormone results in the production of pancreatic juice rich in enzymes but low in volume?
Your Answer:
Correct Answer: Cholecystokinin
Explanation:Cholecystokinin (CCK) mediates digestion in the small intestine by inhibiting gastric emptying and decreasing gastric acid secretion. It stimulates the acinar cells of the pancreas to release a juice rich in pancreatic digestive enzymes, hence the old name pancreozymin.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 130
Incorrect
-
The sympathetic supply to the stomach comes from the:
Your Answer:
Correct Answer: Celiac plexus
Explanation:The vagus nerve supplies the stomach and up to proximal two-thirds of the large intestine and has parasympathetic stimulation. The sympathetic chain which begins at the level of he 1st thoracic vertebra and extends up to 3rd lumbar vertebra gives off the celiac plexus which mainly supplies the stomach. The mesenteric plexus mainly supplies the small intestine and is located below the celiac plexus in the sympathetic chain.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 131
Incorrect
-
The infoldings or spaces between the bases of the villi are known as
Your Answer:
Correct Answer: Crypts of LieberkĆ¼hn
Explanation:An intestinal gland (also crypt of LieberkĆ¼hn 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 132
Incorrect
-
Which part of the cerebellum is primarily responsible for equilibrium and eye movements?
Your Answer:
Correct Answer: Vestibulocerebellum
Explanation:The vestibulocerebellum develops at the same time as the vestibular apparatus in the inner ear. Its regulates balance between agonist and antagonist muscle contractions of the spine, hips, and shoulders during rapid movements.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 133
Incorrect
-
Where does control of self-reactive T cells (self-tolerance) initially occur?
Your Answer:
Correct Answer: Thymus
Explanation:The thymus provides an inductive environment for development of T cells from hematopoietic progenitor cells. In addition, thymic stromal cells allow for the selection of a functional and self-tolerant T cell repertoire. Therefore, one of the most important roles of the thymus is the induction of central tolerance.
-
This question is part of the following fields:
- Immunology
- Medicine
-
-
Question 134
Incorrect
-
Hyperkalaemia [K+ =7meq/l] can lead to the following ECG changes [Ca++ normal]
Your Answer:
Correct Answer: Peaked T waves
Explanation:Hyperkalaemia causes the formation of tall tented T waves due to altered repolarization.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 135
Incorrect
-
Coronary vasoconstriction can be caused by:
Your Answer:
Correct Answer: Beta blockage
Explanation:Coronary arteries contain alpha and beta receptors. The alpha receptor stimulates vasoconstriction and beta receptors stimulate vasodilation. When the chronotropic and inotropic effects of noradrenergic receptors are blocked by a B blocking drug, stimulation of the noradrenergic nerves will cause coronary vasoconstriction.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 136
Incorrect
-
Which of the following would be a contraindication to thrombolysis?
Your Answer:
Correct Answer: Intracranial neoplasm
Explanation:Absolute contraindications to thrombolysis include:
- Previous intracranial bleeding at any time
- Stroke in less than 6 months
- Closed head or facial trauma within 3 months
- Suspected aortic dissection
- Ischemic stroke within 3 months (except in ischemic stroke within 3 hours time)
- Active bleeding diathesis
- Uncontrolled high blood pressure (>180 systolic or >100 diastolic)
- Known structural cerebral vascular lesion
- Arterio-venous malformations
- Thrombocytopenia
- Known coagulation disorders
- Aneurysm
- Brain tumours
- Pericardial effusion
- Septic embolus
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 137
Incorrect
-
The following products of the vascular endothelium produce vasodilation except:
Your Answer:
Correct Answer: Endothelin
Explanation:Endothelin: This is incorrect in the context of vasodilation. Endothelin is actually a potent vasoconstrictor produced by the endothelium, leading to the narrowing of blood vessels and increased blood pressure.
Nitrous oxide (Nitric oxide): This is correct for vasodilation. Nitric oxide is a powerful vasodilator produced by the endothelium, which helps relax and widen blood vessels.
Prostacyclin: This is correct for vasodilation. Prostacyclin (PGI2) is a vasodilator and inhibits platelet aggregation, helping to maintain blood flow and reduce clot formation.
Endothelial-derived hyperpolarizing factor (EDHF): This is correct for vasodilation. EDHF causes vasodilation by hyperpolarizing the smooth muscle cells of blood vessels.
Vascular endothelial growth factor (VEGF): This is correct for vasodilation. VEGF primarily promotes the growth of new blood vessels but also has vasodilatory effects through nitric oxide production.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 138
Incorrect
-
The position of the kidneys besides the vertebral column retroperitoneally spans levels:
Your Answer:
Correct Answer: T12 ā L3
Explanation:The asymmetry within the abdominal cavity, caused by the position of the liver, typically results in the right kidney being slightly lower and smaller than the left, and being placed slightly more to the middle than the left kidney. The left kidney is approximately at the vertebral level T12 to L3, and the right is slightly lower.
-
This question is part of the following fields:
- Medicine
- Renal
-
-
Question 139
Incorrect
-
Cholecystokinin causes the pancreas to
Your Answer:
Correct Answer: Produce pancreatic juice rich in enzymes
Explanation:Cholecystokinin (CCK) mediates digestion in the small intestine by inhibiting gastric emptying and decreasing gastric acid secretion. It stimulates the acinar cells of the pancreas to release a juice rich in pancreatic digestive enzymes, hence the old name pancreozymin. Together these enzymes catalyse the digestion of fat, protein, and carbohydrates.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 140
Incorrect
-
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 ā 18.0 g/dL)WBC: 8.2 x109/l (4 ā 11 x 109/l)Neutrophils: 5.1Ć109/l (1.5 ā 7 x 109/l)Platelets: 280 x109/l (150 ā 400 x 109/L)ESR: 48 mm/hr (0 ā 30 mm/1st hr)Urea, electrolytes and creatinine: normalCXR: patchy airspace shadows bilaterallyWhat is the most likely diagnosis?
Your Answer:
Correct 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 141
Incorrect
-
Which of the following may be a feature of primary hyperaldosteronism?
Your Answer:
Correct Answer: Muscular weakness
Explanation:Primary hyperaldosteronism or Connās syndrome is characterised by hypertension which may cause poor vision or headaches. Occasionally there may be muscular weakness, muscle spasms, tingling sensations, or excessive urination. Complications include cardiovascular disease such as stroke, myocardial infarction, kidney failure, and abnormal heart rhythms.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 142
Incorrect
-
What is the blood supply to the liver?
Your Answer:
Correct 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 143
Incorrect
-
Digoxin causes:
Your Answer:
Correct Answer: Increase in cytosolic calcium concentration
Explanation:Digoxin is a positive inotrope which inhibits NA/K ATPase, increases cardiac contractility and can cause hypokalaemia.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 144
Incorrect
-
To which protein is T3 mostly bound in the serum?
Your Answer:
Correct Answer: Thyroxin-binding globulin
Explanation:In a normal person, approximately 0.03 per cent of the total serum T4, and 0.3 per cent of the total serum T3 are present in free or unbound form. The major serum thyroid hormone-binding proteins are: 1) thyroxine-binding globulin [TBG or thyropexin], 2) transthyretin [TTR or thyroxine-binding prealbumin (TBPA)], and 3) albumin (HAS, human serum albumin). TBG has highest affinity for T4, which is 50-fold higher than that of TTR and 7,000-fold higher that of HSA. As a result TBG binds 75% of serum T4, while TTR and HSA binds only 20% and Albumin 5%, respectively.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 145
Incorrect
-
Which of the following is NOT true of the parasympathetic control of the heart?
Your Answer:
Correct Answer: It can be blocked by beta blockers
Explanation:Parasympathetic fibers do not innervate the Beta receptors on the heart. They are innervated by the sympathetic nerve fibers. Then a beta blocker such as propranolol will block the sympathetic outflow and increase the parasympathetic tone of the heart.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 146
Incorrect
-
The Na-K-2Cl co-transporter occurs in which part of the renal tubule?
Your Answer:
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 147
Incorrect
-
Which of the following phases in depolarization and repolarization of cardiac muscle cells are caused by the inactivation of Na+ channels?
Your Answer:
Correct Answer: Phase 1 : rapid repolarization
Explanation:Phase 0 is caused by the sodium current. Voltage gated sodium channels open leading to the influx of sodium into the cardiac muscle cell. Phase 1 is the rapid transient repolarization phase which is caused by the inactivation of the voltage gated sodium channels and opening of the voltage gated potassium channels along with opening of the slow calcium channels. Phase 2 which is the plateau is caused by opening of the slow calcium channels. Phase 4 is caused by closing of the slow calcium channels and opening of the potassium channels leading to efflux of potassium leading to the establishment of the resting membrane potential.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 148
Incorrect
-
Which of the following refers to the process of decoding messenger RNA into an amino acid sequence?
Your Answer:
Correct Answer: Translation
Explanation:Messenger RNA (mRNA) is decoded in a ribosome, outside the nucleus, to produce a specific amino acid chain, or polypeptide. This is known as translation and follows after the process transcription of DNA to RNA in the cell’s nucleus.
-
This question is part of the following fields:
- Medicine
- Metabolism
-
-
Question 149
Incorrect
-
Which of the following is NOT associated with the development of aortic regurgitation?
Your Answer:
Correct Answer: Dilated cardiomyopathy
Explanation:Aortic insufficiency, is often due to the aortic root dilation, which is idiopathic in over 80% of cases, but otherwise may result from aging, syphilitic aortitis, osteogenesis imperfecta, aortic dissection, Bechet’s disease, reactive arthritis and systemic hypertension. Additionally, aortic insufficiency has been linked to the use of some medications and other potential causes that affect the valve directly including Marfan’s syndrome, EhlersāDanlos syndrome, ankylosing spondylitis, and systemic lupus erythematosus. In acute cases of aortic insufficiency, the main causes are infective endocarditis, aortic dissection or trauma. Dilated cardiomyopathy is associated with the development of mitral regurgitation, not aortic regurgitation
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 150
Incorrect
-
What is the function of the macula densa, located in the wall of the thick ascending limb?
Your Answer:
Correct Answer: Tubuloglomerular feedback.
Explanation:Macula densa cells sense changes in sodium chloride level, and will trigger an autoregulatory response to increase or decrease reabsorption of ions and water to the blood (as needed) in order to alter blood volume and return blood pressure to normal. Tubuloglomerular feedback is one of several mechanisms the kidney uses to regulate glomerular filtration rate (GFR). It involves the concept of purinergic signalling, in which an increased distal tubular sodium chloride concentration causes a basolateral release of adenosine from the macula densa cells. This initiates a cascade of events that ultimately brings GFR to an appropriate level.
-
This question is part of the following fields:
- Medicine
- Renal
-
-
Question 151
Incorrect
-
Presence of which of the following indicates a worse prognosis in rheumatoid arthritis?
Your Answer:
Correct Answer: Anti-CCP antibodies
Explanation:Rheumatoid arthritis is both common and chronic, with significant consequences for multiple organ systems. Anti-cyclic citrullinated peptide (anti-CCP) antibody testing is particularly useful in the diagnosis of rheumatoid arthritis, with high specificity, presence early in the disease process, and ability to identify patients who are likely to have severe disease and irreversible damage. However, its sensitivity is low, and a negative result does not exclude disease. Anti-CCP antibodies have not been found at a significant frequency in other diseases to date, and are more specific than rheumatoid factor for detecting rheumatoid arthritis. The other factors that are mentioned do not play a key prognostic role.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 152
Incorrect
-
The transporter responsible for most glucose absorption in the lumen of the small intestine is called?
Your Answer:
Correct Answer: SGLT 1
Explanation:GLUT = Glucose transporter. GLUT are a family of proteins of different types. GLUT 1 is mainly expressed in erythrocytes, whereas GLUT 2 is mainly expressed by, liver cells and renal tubular cells. GLUT 5 is a sucrose transporter in enterocytes. SGLT- Sodium-dependent glucose cotransporter or sodium-glucose linked transporter are a family of proteins of different types. SGLT1 transporter is found in the intestinal mucosa of the small intestine and SGLT2 in the proximal tubule of the nephron.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 153
Incorrect
-
Protozoa is part of which pathogenic group?
Your Answer:
Correct Answer: Eukaryotes
Explanation:Protozoa are a diverse group of unicellular eukaryotic organisms. Historically, protozoa were defined as single-celled organisms with animal-like behaviours, such as motility and predation.
-
This question is part of the following fields:
- Infectious Diseases
- Medicine
-
-
Question 154
Incorrect
-
Which of the following cancers is responsible in producing osteoblastic bone metastases instead of osteolytic?
Your Answer:
Correct Answer: Prostate adenocarcinoma
Explanation:Osteoblastic (or sclerotic) bone metastases, characterized by deposition of new bone, present in prostate cancer, carcinoid, small cell lung cancer, Hodgkin lymphoma or medulloblastoma.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 155
Incorrect
-
What is the primary cause of ketoacidosis in Type 1 diabetes?
Your Answer:
Correct Answer: Lipolysis
Explanation:in type 1 diabetics the lack of insulin in the bloodstream prevents glucose absorption, thereby inhibiting the production of oxaloacetate (a crucial precursor to the Ī²-oxidation of fatty acids) through reduced levels of pyruvate (a by-product of glycolysis), and can cause unchecked ketone body production (through fatty acid metabolism or lipolysis) potentially leading to dangerous glucose and ketone levels in the blood.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 156
Incorrect
-
Coronary blood flow occurs in?
Your Answer:
Correct Answer: Diastole
Explanation:Coronary arteries are unique in that they fill during diastole, when not occluded by valve cusps nor compressed by myocardial contraction).
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 157
Incorrect
-
The a-wave is created by:
Your Answer:
Correct Answer: Regurgitation of some blood to the great veins when the atria contracts in atrial systole
Explanation:The a-wave created on the venous pulse curve occurs as a result of atrial systole. Due to the pressure build-up in the atria, it causes a back pressure in the vena cava. This pressure is exerted on the valve and this back pressure is what causes a slight increase in the venous pressure.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 158
Incorrect
-
Which protein in the HIV genome is responsible for binding to the host CD4 cells?
Your Answer:
Correct Answer: gp120
Explanation:HIV can infect a variety of immune cells such as CD4+ T cells, macrophages, and microglial cells. HIV-1 entry to macrophages and CD4+ T cells is mediated through interaction of the virion envelope glycoproteins (gp120) with the CD4 molecule on the target cells and also with chemokine coreceptors.
-
This question is part of the following fields:
- Infectious Diseases
- Medicine
-
-
Question 159
Incorrect
-
Question 160
Incorrect
-
Platelets are stored in this body organ.
Your Answer:
Correct Answer: Spleen
Explanation:Megakaryocyte and platelet production is regulated by thrombopoietin. Each megakaryocyte produces between 1,000 and 3,000 platelets during its lifetime. An average of 1011 platelets are produced daily in a healthy adult. Reserve platelets are stored in the spleen, and are released when needed by splenic contraction induced by the sympathetic nervous system.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 161
Incorrect
-
A 47-year-old woman diagnosed with oestrogen receptor positive breast cancer three months ago was started on treatment with tamoxifen. Which of the following is most likely a complaint of this patient during her review today?
Your Answer:
Correct Answer: Hot flushes
Explanation:The most likely complaint of this patient would be hot flushes.
Alopecia and cataracts are listed as possible side-effects, however they are not as prevalent as hot flushes, which are very common in pre-menopausal women.
Tamoxifen is a Selective Oestrogen Receptor Modulator (SERM) which acts as an oestrogen receptor antagonist and partial agonist. It is used in the management of oestrogen receptor-positive breast cancer
Adverse effects:
- Menstrual disturbance: vaginal bleeding, amenorrhoea
- Hot flushes – 3% of patients stop taking tamoxifen due to climacteric side-effects.
- Venous thromboembolism.
- Endometrial cancer (although antagonistic with respects to breast tissue, tamoxifen may serve as an agonist at other sites. Therefore the risk of endometrial cancer is increased). Raloxifene is a pure oestrogen receptor antagonist and carries a lower risk of endometrial cancer.
Tamoxifen is typically used for 5 years following the removal of the tumour.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 162
Incorrect
-
Which of the following is not secreted by cells in the antrum of the stomach?
Your Answer:
Correct Answer: Hydrochloric acid
Explanation:Cells in the body of the stomach secrete mucus, HCl and pepsinogen. Cells in the antrum secrete pepsinogen, gastrin and mucus.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 163
Incorrect
-
The blood supply to the liver is by
Your Answer:
Correct 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.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 164
Incorrect
-
The right border of the heart corresponds to which line on the surface of the chest?
Your Answer:
Correct Answer: Line drawn from the 3rd right costal cartilage to the 6th right costal cartilage
Explanation:The right border corresponds to a line drawn from the 3rd right costal cartilage to the 6th right costal cartilage; this border is slightly convex to the right.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 165
Incorrect
-
Lipid- lowering drugs like Lovastatin reduce cholesterol synthesis by inhibiting which enzyme?
Your Answer:
Correct Answer: HMG-CoA reductase
Explanation:Statins, also known as HMG-CoA reductase inhibitors, are a class of lipid-lowering medications. Statins have been found to reduce cardiovascular disease (CVD) and mortality in those who are at high risk.
-
This question is part of the following fields:
- Medicine
- Metabolism
-
-
Question 166
Incorrect
-
In a 70 kg male, the approximate volumes (litres) of water in the different compartments mentioned (intracellular, interstitial, vascular) are:
Your Answer:
Correct Answer: 28l, 14l, 3.5l
Explanation:In a 70kg male, approximately 60% (42 L) of the total body weight is composed of water divided proportionally in the following compartments:Intracellular fluid (ICF) – Around 67% (28 L) of total body water.Extracellular fluid (ECF) – Approximately 33% (14 L) of the total body fluid. The fluid in the intravascular compartment is about 3 L and is generally about 25% of the volume of ECF.
-
This question is part of the following fields:
- Medicine
- Renal
-
-
Question 167
Incorrect
-
Choose the correct statement. The cells of the liverā¦
Your Answer:
Correct Answer: Help to maintain the normal blood glucose level.
Explanation:Synthesis of vitamin D3 takes place in both the liver and in the kidneys. The liver is responsible for an intermediate step and final synthesis takes place in the kidneys. Immunoglobulins are manufactured by plasma cells in respective organs where there is antigen exposure. The liver plays a major role in maintaining blood glucose levels by converting excess glucose to glycogen and converting glycogen back to glucose in time of need. Hepatocytes have enzymes that can deactivate steroid hormones.
-
This question is part of the following fields:
- Hepatobiliary
- Medicine
-
-
Question 168
Incorrect
-
The function of Troponin T in cardiac muscle is?
Your Answer:
Correct Answer: Allows attachment of troponin components to tropomyosin
Explanation:Troponin T binds the troponin components to tropomyosin. Troponin I inhibits the interaction of myosin with actin, and troponin C contains the binding sites for the Ca2+ that helps initiate contraction.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 169
Incorrect
-
Which enzyme deficiency causes Beriberi?
Your Answer:
Correct 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 170
Incorrect
-
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:
Correct 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 171
Incorrect
-
Myocyte action potentials ā Choose the false statement:
Your Answer:
Correct Answer: Repolarisation is due to net k+ influx
Explanation:Final repolarization (phase 3) to the resting membrane potential (phase 4) is due to closure of the Ca2+ channels and a slow, delayed increase of K+ efflux through various types of K+ channels.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 172
Incorrect
-
Which of the following biochemical profiles is seen in a normal 65 year old female? (in comparison to a normal 24 yr. old female)
Your Answer:
Correct Answer: Increased FSH, LH; decreased oestrogen, progesterone
Explanation:During menopause, a woman’s number of ovarian follicles becomes depleted; as a result, oestrogen and progesterone levels drop, and LH and FSH levels increase. One of the criteria to diagnose menopause is the absence of menstrual period for a year, along with a serum FSH level increased to 30 mIU/ml or higher. LH also rises with the onset of menopause.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 173
Incorrect
-
One function of the liver is synthesis and storage of protein. Which of the following will result in hypoalbuminemia?
Your Answer:
Correct Answer: All of the above
Explanation:Both trauma and sepsis cause an acute inflammatory response causing plasma leakage of albumin. Nephropathy causes leakage of albumin from glomeruli and excretion of albumin in urine known as albuminuria. A hypercatabolic state is characterized by increased circulating catabolic hormones and increase break down of proteins.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 174
Incorrect
-
Question 175
Incorrect
-
What is the function of basic electrical rhythm
Your Answer:
Correct Answer: To coordinate peristalsis and other motor activity
Explanation:The basal or basic electrical rhythm (BER) or electrical control activity (ECA) determines the frequency of the contractions in the gastrointestinal (GI) tract, thus acting to coordinate peristalsis.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 176
Incorrect
-
The V wave in the jugular pulse is caused by:
Your Answer:
Correct Answer: Atrial filling
Explanation:The v wave reflects theĀ passive increase in pressure and volume of the right atrium as it fills in late systole and early diastole.
TheĀ jugular veinĀ pulsations usually have two elevations and two troughs. The first elevationĀ (a wave) corresponds to the slight rise in atrial pressure resulting fromĀ atrial contraction. The first descentĀ (x descent) reflects a fall in atrial pressure that starts with atrial relaxation. The second elevationĀ (v wave)Ā corresponds toĀ ventricular systoleĀ when blood is entering theĀ right atriumĀ from theĀ vena cavaeĀ while theĀ tricuspid valveĀ is closed. Finally, the second descentĀ (y descent)Ā reflects fallingĀ right atrial pressureĀ as the tricuspid valve opens and blood drains from theĀ atriumĀ into the ventricle.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 177
Incorrect
-
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:
Correct 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/Ī¼L, 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 178
Incorrect
-
Xanthines such as caffeine and theophylline are positively inotropic due to:
Your Answer:
Correct Answer: Inhibition of cAMP breakdown
Explanation:Xanthines exert their positive inotropic effect by inhibiting the breakdown of the cAMP resulting in stronger and sustained contractions.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 179
Incorrect
-
A 53 year old female, longstanding case of rheumatoid arthritis comes for a review. Which of the following features are commonly associated with her condition?
Your Answer:
Correct Answer: Proximal interphalangeal joint involvement in the hands
Explanation:Rheumatoid arthritis is a polyarthritis that results in symmetrical pain and swelling of the affected joints (also at rest). It particularly affects the metacarpophalangeal joints (MCPJs) and proximal interphalangeal joints (PIPJs), not the distal interphalangeal joints (DIPs). Ulcerative colitis and IBD are associated with seronegative arthritides, not RA. The condition can also cause various extra-articular manifestations such as ocular symptoms, rheumatoid nodules and pulmonary fibrosis. Scleritis, episcleritis and keratoconjunctivitis sicca are more common than uveitis. Early intervention with disease-modifying antirheumatic drugs (DMARDs) plays a decisive role in successful treatment.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 180
Incorrect
-
The inverse stretch reflex causing muscle relaxation when excessive force is applied to a muscle is mediated by which sensory organ?
Your Answer:
Correct Answer: Golgi tendon organ
Explanation:Both the muscle spindle and Golgi tendon body are proprioceptors. The Golgi tendon reflex is a normal component of the reflex arc of the peripheral nervous system. In a Golgi tendon reflex, skeletal muscle contraction causes the antagonist muscle to simultaneously lengthen and relax. This reflex is also called the inverse myotatic reflex, because it is the inverse of the stretch reflex.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 181
Incorrect
-
Where do the spinothalamic axons decussate?
Your Answer:
Correct Answer: Spinal cord
Explanation:The second order neurons from the spinothalamic tract cross obliquely to the opposite side in the anterior grey and white commissure within one segment of the spinal cord.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 182
Incorrect
-
A 25-year-old female presents to the emergency department with severe breathlessness and tinnitus. She is under treatment for asthma and depression with albuterol and amitriptyline respectively.On examination, she seems agitated with a BP of 100/44, a pulse rate of 112 bpm, a respiratory rate of 30 cycles/min, and a temperature of 37.8'C.An arterial blood gas performed reveals:pH: 7.48 (7.36 ā 7.44)pO2: 11.2 kPa (11.3 ā 12.6 kPa)pCO2: 1.9 kPa (4.7 ā 6.0 kPa)Bicarbonate: 13 mmol/l (20 ā 28 mmol/L)What is the most probable diagnosis?
Your Answer:
Correct Answer: Salicylate poisoning
Explanation:The blood gas analysis provided above is suggestive of a mixed respiratory alkalosis and metabolic acidosis characteristic of salicylate overdose.Pathophysiology:The direct stimulation of the cerebral medulla causes hyperventilation and respiratory alkalosis.As it is metabolized, it causes an uncoupling of oxidative phosphorylation in the mitochondria. Lactate levels then increase due to the increase in anaerobic metabolism. This, along with a slight contribution from the salicylate metabolites result in metabolic acidosis.Tinnitus is characteristic and salicylate ototoxicity may produce deafness. Other neurological sequelae include encephalopathy and agitation, seizures and CNS depression and coma. Cardiovascular complications include tachycardia, hypotension, and dysrhythmias (VT, VF, and asystole).
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 183
Incorrect
-
Which of the following takes place during fasting
Your Answer:
Correct Answer: Migrating motor complex
Explanation:Migrating motor complexes (MMC) are waves of electrical activity that sweep through the intestines in a regular cycle during fasting. These motor complexes trigger peristaltic waves, which facilitate transportation of indigestible substances such as bone, fiber, and foreign bodies from the stomach, through the small intestine, past the ileocecal sphincter, and into the colon.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 184
Incorrect
-
Which of the following proteins are NOT synthesized in the liver?
Your Answer:
Correct Answer: Steroid
Explanation:Human steroidogenesis occurs in a number of locations:- Corticosteroids are produced in the adrenal cortex.- Oestrogen and progesterone are made primarily in the ovary and the placenta during pregnancy, and testosterone in the testes.- Testosterone is also converted to oestrogen to regulate the supply of each in females and males.- Some neurons and glia in the central nervous system (CNS) express the enzymes required for the local synthesis of pregnant neurosteroids, de novo or from peripheral sources.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 185
Incorrect
-
A 18-year-old girl is brought to A&E having ingested at least 16 tablets of paracetamol 8 hours earlier. What should her immediate management consist of?
Your Answer:
Correct Answer: Intravenous N-acetylcysteine
Explanation:Activated charcoal is useful if given within one hour of the paracetamol overdose. Liver function tests, INR and prothrombin time will be normal, as liver damage may not manifest until 24 hours or more after ingestion.The antidote of choice is intravenous N-acetylcysteine, which provides complete protection against toxicity if given within 10 hours of the overdose.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 186
Incorrect
-
The pontine tegmentum as part of the midbrain, contains which cranial nerve nuclei?
Your Answer:
Correct Answer: CN 5 to 8
Explanation:The pontine tegmentum also known as dorsal pons is located within the brain stem. Several cranial nerve nuclei are located in the pontine tegmentum. The nuclei of CN V, CN VI, CN VII and CNVIII are located in the pontine tegmentum.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 187
Incorrect
-
Which one of the following is true about bone marrow?
Your Answer:
Correct Answer: At birth the bone marrow is entirely red marrow and is converted to yellow marrow with age
Explanation:The two types of bone marrow are red marrow, which consists mainly of hematopoietic tissue, and yellow marrow, which is mainly made up of fat cells. Red blood cells, platelets, and most white blood cells arise in red marrow. Both types of bone marrow contain numerous blood vessels and capillaries. At birth, all bone marrow is red. With age, more and more of it is converted to the yellow type; only around half of adult bone marrow is red.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 188
Incorrect
-
Phosphorylation of glucose once it enters the cell is catalysed by which enzyme?
Your Answer:
Correct Answer: Hexokinase
Explanation:Glucose 6-phosphate is produced by phosphorylation of glucose on the sixth carbon. This is catalysed by the enzyme hexokinase in most cells. One molecule of ATP is consumed in this reaction.
-
This question is part of the following fields:
- Medicine
- Metabolism
-
-
Question 189
Incorrect
-
The internodal tract of Bachman:
Your Answer:
Correct Answer: Connects the SA node to the AV node
Explanation:Internodal tract of Bachman connects the SA node to the AV node conducting the electrical impulses generated from the SA node to the AV node and from the AV node to the rest of the electrical complex of the heart.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 190
Incorrect
-
In the clotting mechanism, activation of factor IX can occur through the direct actions of:
Your Answer:
Correct Answer: Factor VIIa & XIa
Explanation:Factor IX is processed to remove the signal peptide, glycosylated and then cleaved by factor XIa (of the contact pathway) or factor VIIa (of the tissue factor pathway). When activated into factor IXa, in the presence of Ca2+, membrane phospholipids, and a Factor VIII cofactor, it hydrolyses one arginine-isoleucine bond in factor X to form factor Xa. Factor IX is inhibited by antithrombin.
-
This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 191
Incorrect
-
Which cranial nerve is responsible for the parasympathetic nerve supply of the thorax and upper abdomen?
Your Answer:
Correct Answer: CN X
Explanation:Cranial nerve X supplies the structures of the thorax and abdomen. All the rest of the cranial nerves supply the structures in the head and neck
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 192
Incorrect
-
What is the most important source of heat production in the body?
Your Answer:
Correct Answer: Skeletal muscle contraction
Explanation:Thermogenesis is the process by which organisms produce heat. Through skeletal muscle contraction, or shivering, ATP is converted into kinetic energy, some of which converts into heat. These muscle contractions produce about 70% of total body heat.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 193
Incorrect
-
Functions of the glossopharyngeal nerve include the following except:
Your Answer:
Correct Answer: Proprioceptive input from muscles of the tongue and larynx
Explanation:The glossopharyngeal nerve is a mixed nerve consisting of both sensory and motor fibers. It has several branches and five distinct general functions:Branchial motor- Special visceral efferent- supplies the Stylopharyngeus muscle and superior constrictor muscle.Visceral motor- general visceral efferent- provides parasympathetic innervation of the parotid gland.Visceral sensory- general visceral afferent- carries visceral sensory information from the carotid sinus and carotid body.General sensory- general somatic afferent- provides general sensory information from the inner surface of the tympanic membrane, upper pharynx and posterior one third of the tongue.Visceral afferent- special visceral afferent- provides taste sensation from the posterior one third of the tongue including the circumvallate papillae.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 194
Incorrect
-
Where in the gastrointestinal tract are valvulae conniventes?
Your Answer:
Correct Answer: Jejunum
Explanation:The circular folds (valves of Kerckring or valvulae conniventes) are large valvular flaps projecting into the lumen of the small intestine.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 195
Incorrect
-
Psoriatic arthropathy most commonly presents with which of the following types of arthritis?
Your Answer:
Correct Answer: Peripheral asymmetric oligoarthropathy
Explanation:Most patients with psoriatic arthritis present with monoarthritis or asymmetric oligoarthritis. The most common form of the disease is the one involving a few joints of the peripheral skeleton with a distinct asymmetry of symptoms. Involvement of the smaller joints of the hands and feet, especially distal interphalangeal joints, seems to be a characteristic feature. Arthritis mutilans is a rare and severe complication of psoriatic arthritis.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 196
Incorrect
-
In the event of an overdose, haemodialysis is ineffective as a treatment modality for which of the following drugs?
Your Answer:
Correct Answer: Tricyclics
Explanation:Tricyclic compounds can’t be cleared by haemodialysis.Drugs that can be cleared with haemodialysis include: (BLAST)- Barbiturate- Lithium- Alcohol (inc methanol, ethylene glycol)- Salicylates- Theophyllines (charcoal hemoperfusion is preferable)Drugs which cannot be cleared with haemodialysis include:- Tricyclics- Benzodiazepines- Dextropropoxyphene (Co-proxamol)- Digoxin- Beta-blockers
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 197
Incorrect
-
Which of the following is the most common clinical feature of carbon monoxide poisoning?
Your Answer:
Correct Answer: Headache
Explanation:Carbon monoxide (CO) poisoning:It is considered as the great imitator of other diseases as the patients present with a myriad of symptoms. The carbon monoxide diffuses rapidly across the pulmonary capillary membrane binding to the haem molecule with a very high affinity (240 times that of oxygen) forming carboxy-haemoglobin (COHb). Non-smokers have a baseline COHb of ,3% while smokers have a baseline COHb of 10-15%.Clinical features of carbon monoxide toxicity:Headache: 90% of cases (most common clinical feature)Nausea and vomiting: 50%Vertigo: 50%Confusion: 30%Subjective weakness: 20%Severe toxicity: ‘pink’ skin and mucosa, hyperpyrexia, arrhythmias, extrapyramidal features, coma, deathCherry red skin is a sign of severe toxicity and is usually a post-mortem finding.Managementā¢ 100% oxygenā¢ Hyperbaric oxygen therapy (HBOT)The use of Hyperbaric oxygen therapy (HBOT) for treatment mild to moderate CO poisoning is not routine.The selection criteria for HBOT in cases of CO poisoning include:ā¢ COHb levels > 20-25%ā¢ COHb levels > 20% in pregnant patient ā¢ Loss of consciousnessā¢ Severe metabolic acidosis (pH <7.1)ā¢ Evidence of end-organ ischemia (e.g., ECG changes, chest pain, or altered mental status)
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 198
Incorrect
-
Which of the following statements is not true about mitochondrial chromosomes?
Your Answer:
Correct Answer: Mitochondrial chromosomes play no role in the transmission of disease from generation to generation.
Explanation:All the above mentioned statements are true except that mitochondrial DNA is passed from the mother to the child. If the child inherits the defective mitochondrial gene it will manifest some form of the disease. Commonly inherited diseases related to mitochondrial abnormality are Leber hereditary optic neuropathy and myoclonic epilepsy with ragged red fibers (MERRF).
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 199
Incorrect
-
There will be a proportion of people in a population who have the given condition, disease or attribute at a specified point in time or over a specified period of time. Which of following is the best term which can describe the above?
Your Answer:
Correct Answer: Prevalence
Explanation:Prevalence refers to the total number of cases of a particular disease or condition present in a population at a specific point in time or over a specified period. It provides a measure of how widespread the disease or condition is within the population.
Specificity and sensitivity are terms used to describe the accuracy of diagnostic tests.
Probability refers to the likelihood of an event occurring.
Incidence isĀ a measure of how commonly or frequently a disease occurs in a specified population over a period by providing a quick measurement of new diseaseĀ diagnoses.
-
This question is part of the following fields:
- Medicine
- Research Skills
-
-
Question 200
Incorrect
-
Neutrophils are attracted to an infected area by:
Your Answer:
Correct Answer: Chemokines
Explanation:The major role of chemokines is to act as a chemoattractant to guide the migration of cells like neutrophils to the site of infection.
-
This question is part of the following fields:
- Immunology
- Medicine
-
SESSION STATS - PERFORMANCE PER SPECIALTY
