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Question 1
Correct
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The Na-K-2Cl co-transporter occurs in which part of the renal tubule?
Your 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.
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This question is part of the following fields:
- Medicine
- Renal
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Question 2
Correct
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What type of intercellular connection found between cardiac muscle fibers allow for the spread of excitation from one cell to another?
Your Answer: Gap junctions
Explanation:The cardiac muscles have gap junctions in-between the cells. They form 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.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 3
Correct
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Transportation of proteins from the cell body to axonal terminals is known as:
Your Answer: Axoplasmic flow
Explanation:Transportation of proteins from the cell body to axonal terminals is known as axoplasmic, axonal flow or Axonal transport.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 4
Incorrect
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A 31 year old female with systemic lupus erythematosus wants to know if she has any predisposing factors for the disease. Which of the following carries the greatest risk of developing SLE?
Your Answer: Positive HLA–DR2
Correct Answer: Monozygotic twin
Explanation:An overall concordance rate in monozygotic twins was documented to be 25% as compared to dizygotic twins with 3%. First degree relatives have a chance of around 3% of developing the disease. Caucasians show an increase frequency of HLA-B8. The Japanese lupus patients had a stronger association with HLA-DR2.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 5
Correct
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During which phase of meiosis does exchange of genetic material occur accounting for genetic diversity between individuals:
Your Answer: Prophase 1
Explanation:Prophase 1 has been divided into five different stages ( laptotene, zygotene, pachytene, diplotene ans diakinesis). In prophase 1 chromosomes are going to condense to become visible, each chromosome will contain two chromatids that are joined at the centromere. the nucleolus and nuclear envelope are going to disintegrate. the homologous chromosomes will form tetrad and crossing over will occur between the chromosomes (random exchange of genes), the point of exchange is known as the chiasmata, this increases genetic diversity.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 6
Correct
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The predominant site in the lymph node where B lymphocytes are found is:
Your Answer: Cortex
Explanation:The cortex of the lymph node consists of the lymphoid nodules and sinusoids and posses a germinal centre from which B cells proliferate. The cortex of the lymph node predominately consists of B cells.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 7
Incorrect
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During quiet breathing the diaphragm’s role accounts for what percent of respiration?
Your Answer: 25%
Correct Answer: 75%
Explanation:The contraction of the diaphragm accounts for approximately 75% of the air movement during normal breathing.
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 8
Correct
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Which are the main hormones secreted by the posterior pituitary gland.
Your Answer: Oxytocin and vasopressin
Explanation:The posterior pituitary gland secretes oxytocin and vasopressin (antidiuretic hormone). These hormones are stored in Herring bodies before being secreted into the bloodstream.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 9
Correct
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Near the transcription site of a gene, the site at which RNA polymerase and its cofactors bind is known as the:
Your Answer: Promotor
Explanation:Transcription will begin when the RNA polymerase II binds to the promotor. The promotor is a sequence of 25 nucleotides found upstream from the start site of transcription. This promotor sequence is known as the TATA box. Transcription factors also bond along with RNA polymerase to this site to form a complex. However some may bind to regulatory elements proximal to the promotor site.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 10
Correct
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Question 11
Incorrect
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Which statement is incorrect regarding transcription of DNA?
Your Answer: Only two AT-rich promoter sites are present in eukaryotic cells, i.e. TATA box and CAAT box.
Correct Answer: A gene is always read in the 3’-5’ orientation and at 3’ 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.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 12
Incorrect
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On which chromosome is the gene for insulin located?
Your Answer: Chromosome 12
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.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 13
Correct
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Carotid bodies...
Your Answer: Are located near the bifurcation of the carotid arteries bilaterally
Explanation:The carotid body is a small cluster of chemoreceptors and supporting cells located near the fork (bifurcation) of the carotid artery (which runs along both sides of the throat).The carotid body detects changes in the composition of arterial blood flowing through it, mainly the partial pressure of oxygen, but also of carbon dioxide. Furthermore, it is also sensitive to changes in pH and temperature. Carotid bodies trigger an action potential through the afferent fibers of the glossopharyngeal nerve,
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 14
Correct
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Which cranial nerve is responsible for the parasympathetic nerve supply of the thorax and upper abdomen?
Your 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
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This question is part of the following fields:
- Medicine
- Neurology
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Question 15
Correct
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Which of the following cells secrete glucagon?
Your Answer: A cells
Explanation:Glucagon counteracts hypoglycaemia and opposes insulin by promoting gluconeogenesis and glycogenolysis. It also decreases fatty acid synthesis in the liver and adipose tissue, and promotes lipolysis. It is secreted by the pancreatic islet α-cells. Its production is regulated by the insulin produced in β-cells.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 16
Correct
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Which of the following is correctly paired?
Your Answer: F cells : pancreatic polypeptide
Explanation:Pancreatic polypeptide is secreted by F-cells, which represent the smallest proportion of islet cells in the pancreas. These cells establish the embryological origin of the pancreas. Pancreatic polypeptide regulates endocrine and exocrine activities by the pancreas.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 17
Incorrect
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Consanguinity shows a strong association with which pattern of inheritance?
Your Answer: X linked recessive
Correct Answer: Autosomal recessive
Explanation:Consanguinity involves being from the same kinship as another person. It is a common feature of an autosomal recessive mode of inheritance
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This question is part of the following fields:
- Genetics
- Medicine
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Question 18
Correct
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With regards to the deiodinases, where would you find D1?
Your Answer: Liver
Explanation:The liver produces an important amount of T3 by outer ring deiodination thanks to its elevated concentration of type I deiodinase. It can also be found in the kidney.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 19
Correct
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The chief cells of the stomach secrete which of the following?
Your Answer: Pepsinogens
Explanation:A gastric chief cell (or peptic cell, or gastric zymogenic cell) is a type of cell in the stomach that releases pepsinogen and gastric lipase.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 20
Correct
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Neutrophils are attracted to an infected area by:
Your 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.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 21
Correct
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A 56 year old woman presents to the clinic complaining of shoulder pain that she has been experiencing for the last 4 weeks. She does not remember getting injured previously. The pain worsens on movement especially when she is moving the arm quickly. At night, lying on the affected side is painful. Examination reveals no erythema or swelling. However, pain is felt on passive abduction between 60 to 120 degrees and she is unable to abduct the arm past 70-80 degrees. Flexion and extension are intact. What is the most likely diagnosis?
Your Answer: Supraspinatus tendonitis
Explanation:Supraspinatus tendinopathy is a common and disabling condition that becomes more prevalent after middle age and is a common cause of pain in the shoulder. A predisposing factor is resistive overuse. This patient has the classic painful arc that is a sign of shoulder impingement characteristic of supraspinatus tendonitis.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 22
Correct
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Which cell secretes parathyroid hormone?
Your Answer: Chief cells
Explanation:Parathyroid chief cells, also known as parathyroid principal cells or parathyroid cells, are the most prevalent type of cell in the parathyroid gland and the only ones present at birth. They secrete parathyroid hormone (PTH).
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 23
Correct
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Angina pectoris develops when blood through the coronary artery becomes:
Your Answer: Restricted, limiting blood blow
Explanation:Angina pectoris develops when stenosis ( >70%) of the artery occurs as a result of formation of an atherosclerotic plaque. This leads to a decrease in the O2 carried to the thickened heart muscle by the blood, leading to the characteristic chest pain associated with angina pectoris.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 24
Correct
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Which of the following hormones cause negative feedback on the CRH/ACTH axis?
Your Answer: Cortisol
Explanation:The hypothalamic–pituitary–adrenal axis, also known as HPA axis is a set of interactions that regulate the secretion of several hormones through negative feedback. Cortisol, for example, is produced by the adrenal cortex, binds to its receptors in the hypothalamus and adenohypophysis and inhibits secretion of corticotropin releasing hormone (CRH) and adrenocorticotropic hormone (ACTH). The drop in CRH secretion leads to a decrease in ACTH secretion, which in turn causes less cortisol to be secreted.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 25
Correct
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The Cellular Theory of Ageing involves?
Your Answer: Loss of telomeres
Explanation:Cellular theories of aging propose that human aging is the result of cellular aging, whereby an increasing proportion of cells reach senescence, a terminal stage at which cells will cease to divide. This will limit the body’s ability to regenerate and to respond to injury or stress. Telomeres are bits of DNA on the ends of chromosomes that protect chromosomes from sticking to each other or tangling, which could cause DNA to abnormally function. As cells replicate, telomeres shorten at the end of chromosomes, and this process correlates to senescence or cellular aging.
Other theories include:
- The Free Radical Theory: Implicates the gradual accumulation of oxidative cellular damage as a fundamental driver of cellular aging. This theory has evolved over time to emphasize the role of free radical induced mitochondrial DNA (mtDNA) mutations and the accumulation of mtDNA deletions. Given the proximity of mtDNA to the electron transport chain, a primary producer of free radicals, it postulates that the mutations would promote mitochondrial dysfunction and concomitantly increase free radical production in a positive feedback loop. It is known that diet, lifestyle, drugs (e.g. tobacco and alcohol) and radiation etc., are all accelerators of free radical production within the body.
- Error theory: based on the idea that errors can occur in the transcription of the synthesis of DNA. These errors are perpetuated and eventually lead to systems that do not function at the optimum level. The organism’s aging and death are attributable to these events (Sonneborn, 1979).
- The Cross-Linking Theory: also referred to as the Glycosylation Theory of Aging. In this theory it is the binding of glucose (simple sugars) to protein, (a process that occurs under the presence of oxygen) that causes various problems. Once this binding has occurred the protein becomes impaired and is unable to perform as efficiently. Living a longer life is going to lead to the increased possibility of oxygen meeting glucose and protein and known cross-linking disorders include senile cataract and the appearance of tough, leathery and yellow skin.
- The Neuroendocrine Theory First proposed by Professor Vladimir Dilman and Ward Dean MD, this theory elaborates on wear and tear by focusing on the neuroendocrine system. This system is a complicated network of biochemicals that govern the release of hormones which are altered by the walnut sized gland called the hypothalamus located in the brain. The hypothalamus controls various chain-reactions to instruct other organs and glands to release their hormones etc. The hypothalamus also responds to the body hormone levels as a guide to the overall hormonal activity. But as we grow older the hypothalamus loses it precision regulatory ability and the receptors which uptake individual hormones become less sensitive to them. Accordingly, as we age the secretion of many hormones declines and their effectiveness (compared unit to unit) is also reduced due to the receptors down-grading
- The Membrane Theory of Aging: According to this theory it is the age-related changes of the cell’s ability to transfer chemicals, heat and electrical processes that impair it. As we grow older the cell membrane becomes less lipid (less watery and more solid). This impedes its efficiency to conduct normal function and in particular there is a toxic accumulation
- The Decline Theory: The mitochondria are the power producing organelles found in every cell of every organ. Their primary job is to create Adenosine Triphosphate (ATP) and they do so in the various energy cycles that involve nutrients such as Acetyl-L-Carnitine, CoQ10 (Idebenone), NADH and some B vitamins etc. Enhancement and protection of the mitochondria is an essential part of preventing and slowing aging. Enhancement can be achieved with the above mention nutrients, as well as ATP supplements themselves.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 26
Correct
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Antibiotic resistance may happen by:
Your Answer: By enzymes which inactivate the drug
Explanation:The three main mechanisms of antibiotic resistance are, enzymatic degradation of antibacterial drugs, alteration of bacterial proteins that are antimicrobial targets, and changes in membrane permeability to antibiotics.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 27
Incorrect
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Which of the following factors is directly responsible for the breakdown of fibrinogen to fibrin?
Your Answer: Plasmin
Correct Answer: Thrombin
Explanation:Prothrombin (coagulation factor II) is proteolytically cleaved to form thrombin in the coagulation cascade, the clotting process. Thrombin in turn acts as a serine protease that converts soluble fibrinogen into insoluble strands of fibrin, as well as catalysing many other coagulation-related reactions.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 28
Correct
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Which of the following conditions has no effect on cardiac output?
Your Answer: Sleep
Explanation:Sleep has no effect on the cardiac output. Anxiety, excitement and pregnancy will increase the cardiac output. Standing from a lying position will decrease the cardiac output transiently.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 29
Correct
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In Argyll Robertson pupils…
Your Answer: All of the options given
Explanation:Argyll Robertson pupils are bilaterally small pupils that accommodate or reduce in size near an object but do not react to light. They do not constrict when exposed to bright light. They are a highly specific sign of neurosyphilis but may be seen in diabetic neuropathy as well.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 30
Incorrect
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Which of the following drugs is NOT bacteriostatic?
Your Answer: Chloramphenicol
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.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 31
Incorrect
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Which of the given adverse effects should be anticipated following the administration of an anticholinesterase?
Your Answer: Tachycardia and lacrimation
Correct Answer: Bradycardia and miosis
Explanation:Bradycardia and miosis should be anticipated following the administration of anticholinesterases.Anticholinesterase agents include the following medications:- Pyridostigmine, neostigmine, and edrophonium which play a significant role in the diagnosis and the management of myasthenia gravis.- Rivastigmine, galantamine and donepezil are cholinesterase inhibitors found to be significantly useful in the management of Alzheimer’s disease.Mechanism of action and pharmacological effects:Inhibition of cholinesterase increases the level and the duration of action of acetylcholine within the synaptic cleft. Thus, cholinergic effects such as a reduction in heart rate (bradycardia), miosis (pupillary constriction), increased secretions, increased gastrointestinal motility and reduction in BP may occur with anticholinesterases.Toxins such as organophosphates and carbamates also are primarily anticholinergic and cause the following typical SLUDGE symptoms:- Salivation- Lacrimation- Urination- Diaphoresis- Gastrointestinal upset- Emesis
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 32
Incorrect
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Where is the myenteric plexus (Auerbach’s plexus) located in the GIT?
Your Answer: Between the outer longitudinal muscle layer and the adventitia
Correct Answer: Between the outer longitudinal and middle circular muscle layers.
Explanation:A part of the enteric nervous system, the myenteric plexus exists between the longitudinal and circular layers of muscularis externa in the gastrointestinal tract. It is found in the muscles of the oesophagus, stomach, and intestine.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 33
Incorrect
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Which of the following best describe Clostridium infection?
Your Answer: Gram positive bacilli
Correct Answer: Anaerobe
Explanation:Clostridium is a genus of Gram-positive bacteria, which includes several significant human pathogens, including the causative agent of botulism and an important cause of diarrhoea, Clostridium difficile. They are obligate anaerobes capable of producing endospores. The normal, reproducing cells of Clostridium, called the vegetative form, are rod-shaped, which gives them their name, from the Greek κλωστήρ or spindle.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 34
Correct
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The AV Node:
Your Answer: It decelerates impulses passing to the ventricles
Explanation:The action potentials in the sinoatrial (SA) and atrioventricular (AV) nodes are largely due to Ca2+, with no contribution by Na+ influx. The depolarization continues to conduct slowly through the atrioventricular (AV) node. The AV node is located in the right posterior portion of the interatrial septum. This is small and bean-shaped. The atrial conductive system is organized so that the cardiac impulse does not travel from the atria into the ventricles too rapidly; this delay allows the atria to empty before ventricular contraction begins. It is the AV node and its adjacent conductive fibers that delay this transmission into the ventricles. Conduction through the AV Node is represented on the ECG by the PR interval.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 35
Incorrect
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A 23 year old man presents with a painful right elbow and left Achilles tendon. He also gives history of dysuria, fever and conjunctivitis. Examination reveals macules and pustules on his hands. He has returned from a trip to Far East 3 weeks ago and admits to having unprotected sex. Which of the following is the most likely diagnosis?
Your Answer: Gonococcal arthritis
Correct Answer: Reactive arthritis
Explanation:Reactive arthritis, (formerly known as Reiter’s syndrome), is an autoimmune condition that occurs after a bacterial infection of the gastrointestinal or urinary tract. It is categorized as a seronegative spondylarthritis because of its association with HLA-B27. Reactive arthritis primarily affects young men and usually presents with musculoskeletal or extra‑articular symptoms. The characteristic triad consists of arthritis, conjunctivitis, and urethritis. The diagnosis is based on clinical features such as patient history and physical examination; there are no specific tests for reactive arthritis. Treatment is primarily symptomatic and consists of the administration of NSAIDs, as most patients recover spontaneously. extraarticular dermatologic manifestations include skin lesions of the glans resembling psoriasis (balanitis circinata); hyperkeratinisation of the palms and soles (keratoderma blenorrhagicum), oral ulcers. Other STDs including HIV, syphilis have different presentations. Psoriatic arthritis is not commonly associated with urethritis and conjunctivitis.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 36
Correct
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The postextrasystolic potentiation of myocardial contractility is due to:
Your Answer: Increase in intracellular Ca2+
Explanation:The postextrasystolic potentiation of myocardial contractility Is not due to ventricular filling. It occurs in isolated locations in the heart and is due to increase availability of intracellular calcium.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 37
Incorrect
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Which of the following is a characteristic clinical finding of opioid poisoning?
Your Answer: Sweating and lacrimation
Correct Answer: Bradycardia
Explanation:Opioid poisoning is classically associated with pinpoint pupils, reduced respiratory rate, bradycardia, drowsiness and coma. Hypothermia is a feature of barbiturate poisoning, while sweating and lacrimation are seen in cases of opiate withdrawal.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 38
Correct
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Amino acid reabsorption occurs most markedly in the?
Your Answer: Proximal convoluted tubule
Explanation:Renal protein reabsorption is the part of renal physiology that deals with the retrieval of filtered proteins, preventing them from disappearing from the body through the urine. Almost all reabsorption takes place in the proximal tubule. Only ,1% is left in the final urine.
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This question is part of the following fields:
- Medicine
- Renal
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Question 39
Incorrect
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Bile acids will be prevented from being absorbed by resection of which part of the gastrointestinal tract?
Your Answer: Duodenum
Correct Answer: Ileum
Explanation:Bile acids (also called bile salts) are produced in the liver, secreted into the biliary system, stored in the gallbladder and are released after meals stimulated by cholecystokinin. They are important for the digestion and absorption of fats (lipids) in the small intestine. Usually over 95% of the bile acids are absorbed in the terminal ileum and are taken up by the liver and resecreted.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 40
Correct
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Which of the following best describe N. Meningitides?
Your Answer: Gram negative cocci
Explanation:Neisseria meningitidis, often referred to as meningococcus, is a gram negative bacterium that can cause meningitis and other forms of meningococcal disease such as meningococcaemia, a life-threatening sepsis. The bacterium is referred to as a coccus because it is round, and more specifically, diplococcus because of its tendency to form pairs. About 10% of adults are carriers of the bacteria in their nasopharynx.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 41
Correct
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During strenuous exercise the following arterial change can take place in a fit athlete:
Your Answer: No change takes place
Explanation:The changes which occur in arterial pH, PO2 and PCO2 values during exercise are usually small. Arterial PO2 often rises slightly because of hyperventilation although it may eventually fall at high work rates. During vigorous exercise, when sufficient oxygen for flux through the Krebs cycle is not available, the increased reliance on glycolysis results in increased accumulation of lactic acid, which initially leads to an increase in PaCO2 . However, this is counteracted by the stimulation of ventilation and as a result PaCO2 is decreased. This provides some respiratory compensation for further lactic acid production and prevents a decline in blood pH, which remains nearly constant during moderate exercise.
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 42
Correct
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Question 43
Correct
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Where is the majority of Mg2+ absorbed?
Your Answer: Thick ascending limb of loop of Henle.
Explanation:Although the majority of the filtered magnesium is reabsorbed within the ascending loop of Henle, it is now recognized that the distal tubule also plays an important role in magnesium conservation.
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This question is part of the following fields:
- Medicine
- Renal
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Question 44
Incorrect
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Which of the following pairs are correct concerning arteriolar tone?
Your Answer: Neural control: vasoconstriction activated by sympathetic nerves
Correct Answer: Hormonal control: catecholamines affect the adrenergic receptors of the vascular smooth muscle
Explanation:Catecholamines released from the adrenal medulla act on the noradrenergic receptors of the vascular smooth muscles. In the skeletal muscles and liver it causes vasodilation whilst it causes vasoconstriction in the rest of the blood vessels of the body.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 45
Correct
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In which organ will you find extremely porous sinusoidal capillaries, with discontinuous endothelium?
Your Answer: Liver
Explanation:The liver is the organ which contains sinusoidal capillaries with discontinuous endothelium. The brain, lungs and the intestine all contain continuous capillaries, however the kidney contains fenestrated capillaries to aid in filtration.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 46
Correct
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One function of the liver is synthesis and storage of protein. Which of the following will result in hypoalbuminemia?
Your 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.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 47
Correct
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Which membrane bound protein in the sarcoplasmic reticulum regulates calcium return from the cytosol to the sarcoplasmic reticulum?
Your Answer: Phospholamban
Explanation:Phosphorylation of phospholamban 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 sarcoplasmic reticulum (SR), that controls the rate of uptake of calcium into the SR. The latter effect explains enhanced relaxation (lusitropic effect).
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 48
Incorrect
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Live active or attenuated vaccines:
Your Answer: Side effect may be toxicity
Correct Answer: Side effect may be egg hypersensitivity
Explanation:Live attenuated vaccines consist of a weakened form of the virus itself and have both advantages and disadvantages. Although they can exert an excellent immune response, potential risks exist. One such concern is the risk of reversion to a more virulent strain of virus. They are easily damaged or destroyed by heat and light, making it even more important that they be stored and refrigerated with care. Live vaccines are not given to immunocompromised persons. A few live vaccines against viruses include: oral polio, measles, mumps, rubella, rota virus and yellow fever. Eggs are used to produce Measles- mumps- rubella vaccine (MMR) and thus hypersensitivity may occur.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 49
Correct
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With regard to cell membrane proteins:
Your Answer: Carriers are involved in facilitated diffusion
Explanation:Pumps use a source of free energy such as ATP to transport ions against a gradient and is an example of active transport. Unlike channel proteins which only transport substances through membranes passively, carrier proteins can transport ions and molecules either passively through facilitated diffusion, or via secondary active transport. Channels are either in open state or closed state. When a channel is opened, it is open to both extracellular and intracellular. Pores are continuously open to both environments, because they do not undergo conformational changes. They are always open and active.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 50
Correct
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A 65-year-old man presents to you three weeks after initiating metformin for type 2 diabetes mellitus. His body mass index is 27.5 kg/m^2. At a dose of 500mg TDS the patient has experienced significant diarrhoea. Even on reducing the dose to 500mg BD his symptoms persisted. What is the most appropriate next step in this patient?
Your Answer: Start modified release metformin 500mg od with evening meal
Explanation:Here, the patient seems to be intolerant to standard metformin. In such cases, modified-release preparations is considered as the most appropriate next step. There is some evidence that these produce fewer gastrointestinal side-effects in patients intolerant of standard-release metformin.Metformin is a biguanide and reduces blood glucose levels by decreasing the production of glucose in the liver, decreasing intestinal absorption and increasing insulin sensitivity. Metformin decreases both the basal and postprandial blood glucose.Other uses: In Polycystic Ovarian Syndrome (PCOS), Metformin decreases insulin levels, which then decreases luteinizing hormone and androgen levels. Thus acting to normalize the menstruation cycle.Note:Metformin is contraindicated in patients with severe renal dysfunction, which is defined as a glomerular filtration rate (GFR) less than 30 ml/min/1.732m2. Metformin overdose has been associated with hypoglycaemia and lactic acidosis, for this reason, it has a black box warning for lactic acidosis.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 51
Correct
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The following contributes to the rate of depolarization?
Your Answer: All of the options given
Explanation:Depolarization occurs due to impulses generated by the SA node. As the heart beats to the rhythm of the SA node, certain factors will effect the rate of depolarization. All the mentioned options effect the rate of depolarization.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 52
Incorrect
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Question 53
Correct
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A study is carried out to assess the efficacy of a new anti-epileptic drug for children with absence seizures. The total number of the children selected for the study was 400, from which 150 children were assigned to take the new drug and 250 children were assigned in the control group. After a period of four months, only 15 children taking the new drug had a seizure compared to 100 children from the control group who had seizure. What is the correct value regarding the relative risk reduction?
Your Answer: 75%
Explanation:Relative risk reduction (RRR) tells you by how much the treatment reduced the risk of bad outcomes relative to the control group who did not have the treatment. In the previous example, the relative risk reduction of fever and rash in the group of the children on the intervention was 40 per cent (1 – 0.6 = 0.4 or 40 per cent). RRR = (EER -CER) / CER = (0.1 – 0.4) / 0.4 = -0.75 or 75% reduction.
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This question is part of the following fields:
- Medicine
- Research Skills
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Question 54
Correct
-
Which statement about antithrombin III is true?
Your 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.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 55
Correct
-
Regarding the innervation of the cerebral blood vessels, postganglionic sympathetic neurons have their cell bodies in the:
Your Answer: Superior cervical ganglia
Explanation:The superior cervical ganglion (SCG) is a part of autonomic system which plays a major role in maintaining homeostasis of the body. This ganglion innervates structures in the head and neck and is the largest and the most superiorly located ganglion. The SCG provides sympathetic innervation to structures within the head, including the pineal gland, the blood vessels in the cranial muscles and the brain, the choroid plexus, the eyes, the lacrimal glands, the carotid body, the salivary glands, and the thyroid gland. The postganglionic axons of the SCG innervate the internal carotid artery and form the internal carotid plexus. The internal carotid plexus carries the postganglionic axons of the SCG to the eye, lacrimal gland, mucous membranes of the mouth, nose, and pharynx, and numerous blood-vessels in the head.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 56
Incorrect
-
Regarding CSF:
Your Answer: Blockage of the foramina results in a communicating hydrocephalus
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.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 57
Correct
-
HCL is secreted by which cells in the stomach
Your Answer: Parietal cells
Explanation:Parietal cells are the epithelial cells that secrete hydrochloric acid (HCl) and intrinsic factor. These cells are located in the gastric glands found in the lining of the fundus and in the body of the stomach.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 58
Correct
-
Where is retinol mainly stored?
Your Answer: Liver
Explanation:Vitamin A is a group of unsaturated nutritional organic compounds that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids (most notably beta-carotene). The liver stores a multitude of substances, including glucose (in the form of glycogen), vitamin A (1–2 years’ supply), vitamin D (1–4 months’ supply), vitamin B12 (3–5 years’ supply), vitamin K, iron, and copper.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 59
Correct
-
Using the Cockcroft-Gault formula, what will the estimated creatinine clearance be of a 55 year old male who weighs 75kg and has a serum creatinine of 150mg/dL?
Your Answer: 0.59ml/min
Explanation:A commonly used surrogate marker for estimate of creatinine clearance is the Cockcroft-Gault (CG) formula, which in turn estimates GFR in ml/min:CCr = [(140-age) x Mass(kg)]/[72 x serum creatinine (mg/dL)](multiply by 0.85 for women)Therefore CCr = (85 x 75)/(72 x 150) = 0.59
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This question is part of the following fields:
- Medicine
- Renal
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Question 60
Incorrect
-
A lesion that interrupts one optic nerve causes blindness:
Your Answer: In the eye on the contralateral side
Correct Answer: In the eye on the same side as the optic nerve
Explanation:The optic nerve on each side contains medial and lateral fibers originating from the retina. Medial fibers cross at the optic chiasm and become the optic tract ending in the visual cortex of the occipital lobe. If there is a lesion interrupting the “optic nerve” on one side, the same side eye will be completely blind.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 61
Correct
-
Portal vein receives its blood from all the following except:
Your Answer: Kidney
Explanation:The portal vein receives blood from the intestines via the superior and inferior mesenteric veins, from stomach via the gastric veins and from the spleen and pancreas via splenic vein. The kidney is supplied by the renal artery and drains into the renal vein into the inferior venacava.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 62
Incorrect
-
A 70-year-old male with advanced COPD currently on treatment with salbutamol (as required) presents for review. After a complete history and examination, you conclude that he requires to be stepped up in his inhalational therapy. The decision to add tiotropium bromide to his regime was taken. Which of the following best describe the mechanism of action of tiotropium?
Your Answer: It is a short-acting anticholinergic agent
Correct Answer: It is a long-acting anticholinergic agent
Explanation:Tiotropium is a specific long-acting antimuscarinic agent indicated as maintenance therapy for patients with COPD (chronic obstructive pulmonary disease). It should be used cautiously in patients with narrow-angle glaucoma, prostatic hyperplasia or bladder neck obstruction.The most frequently encountered adverse effects of tiotropium include pharyngitis, bronchitis, sinusitis, dry mouth, cough, and headaches. Paradoxical bronchospasm may also occur as a rare side-effect. Dry mouth occurs in up to 14% of patients taking tiotropium, in keeping with its anticholinergic profile. Rarer side-effects include tachycardia, blurred vision, urinary retention, and constipation.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 63
Incorrect
-
A 30-year-old male is brought to the emergency department following his collapse in a night club. His friends who accompanied him admit that, of recent, he has been using increasing amounts of cocaine. Which among the following is commonly associated with cocaine overdose?
Your Answer: Hypothermia
Correct Answer: Metabolic acidosis
Explanation:Metabolic acidosis is associated with cocaine overdose. In overdose, cocaine leads to agitation, tachycardia, hypertension, sweating, hallucinations, and finally convulsions. Metabolic acidosis, hyperthermia, rhabdomyolysis, and ventricular arrhythmias also occur.Chronic use may be associated with premature coronary artery disease, dilated cardiomyopathy, and increased risk of cerebral haemorrhage.There are 3 stages for acute cocaine toxicity:Stage I: CNS symptoms of headache, vertigo, pseudo hallucinations, hyperthermia, hypertension. Stage II: increased deep tendon reflexes, tachypnoea, irregular breathing, hypertension.Stage III: Areflexia, coma, fixed and dilated pupils, hypotension, ventricular fibrillation, apnoea, and respiratory failure.Treatment:- Airway, breathing, and circulation to be secured. The patient’s fever should be managed, and one should rule out hypoglycaemia as a cause of the neuropsychiatric symptoms. – Cardiovascular toxicity and agitation are best-treated first-line with benzodiazepines to decrease CNS sympathetic outflow.- The mixed beta/alpha blocker labetalol is safe and effective for treating concomitant cocaine-induced hypertension and tachycardia.- Non-dihydropyridine calcium channels blockers such as diltiazem and verapamil have been shown to reduce hypertension reliably, but not tachycardia. – Dihydropyridine agents such as nifedipine should be avoided, as reflex tachycardia may occur. – The alpha-blocker phentolamine has been recommended but only treats alpha-mediated hypertension and not tachycardia.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 64
Correct
-
The coronary arteries fill during?
Your Answer: Diastole
Explanation:During systole the coronary arteries collapse as a result of the pressure due to contraction that is exerted on them. During diastole the heart muscle relaxes and the pressure on the coronary vessels is relieved allowing blood to flow through them to the subendocardium.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 65
Correct
-
A 20 year old male student presents to the clinic with swelling of his face, hands and feet along with diffuse abdominal pain. He has a history of similar recurrent episodes since he was 10 years old, with each episode lasting 2-3 days. Examination reveals swelling on face, hands, feet but no sign of urticaria. Family history is significant for similar episodes in the mother who experienced these since childhood, and a brother who passed away following respiratory distress at age of 8 during one such episode. Which of the following tests would be the most helpful in reaching the diagnosis?
Your Answer: C1 esterase inhibitor
Explanation:Hereditary C1 inhibitor deficiency leads to recurrent angioedema without urticaria or pruritus. Physical triggers include dental work, surgery or intubation. Medical triggers include angiotensin-converting enzyme (ACE) inhibitor, tamoxifen, oestrogen-containing medications (e.g., hormone replacement therapy and oral contraceptives). It is diagnosed on the basis of low levels of C1 esterase inhibitor or elevated levels of dysfunctional C1 esterase inhibitor. C4 levels are low between attacks. IgE levels, eosinophils, skin prick tests and RASTs are helpful in other allergic conditions and asthma but not of use in this case.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 66
Correct
-
In which phase do chromosomes in the nucleus become completely condensed into well-defined chromosomes?
Your Answer: Metaphase
Explanation:Prophase begins when the nucleus envelope disintegrates and the chromosomes start to condense. The chromosomes consist of two sister chromatids that are joined at a constriction known as centromere. When the cell reaches the metaphase the chromosomes are completely condensed and ready to align on the equatorial plate
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This question is part of the following fields:
- Genetics
- Medicine
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Question 67
Correct
-
Which is true of the citric acid cycle?
Your Answer: Involves a series of reactions where oxaloacetate is regenerated
Explanation:The cycle consumes acetate (in the form of acetyl-CoA) and water, reduces NAD+ to NADH, and produces carbon dioxide as a waste by-product. The NADH generated by the citric acid cycle is fed into the oxidative phosphorylation (electron transport) pathway. At the end of each cycle, the four-carbon oxaloacetate has been regenerated, and the cycle continues. The net result of these two closely linked pathways is the oxidation of nutrients to produce usable chemical energy in the form of ATP. Acetyl-CoA, is the starting point for the citric acid cycle and in eukaryotic cells, the citric acid cycle occurs in the matrix of the mitochondrion. Though the Krebs cycle does not directly require oxygen, it can only take place when oxygen is present because it relies on by-products and is therefore an aerobic process.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 68
Correct
-
Embryologically the anterior pituitary is formed from?
Your Answer: Rathkes pouch
Explanation:The ectoderm, located in the roof of the pharynx, forms Rathke’s pouch, which comes into contact with the ectoderm of the developing brain. The pouch eventually separates from the pharynx, becoming the anterior pituitary.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 69
Correct
-
The pressure in the portal circulation is normally adjusted in the:
Your Answer: Sinusoids
Explanation:The pressure in the portal circulation depends on the pressure of the hepatic sinusoids mainly because the direction of transport of nutrients in the portal vein occurs from the portal vein to the hepatic sinusoids.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 70
Correct
-
Which receptor type is associated with the inhibition of pancreatic endocrine secretion?
Your Answer: Α2
Explanation:The activation of alpha 2-adrenergic receptors in pancreatic beta-cells works by inhibiting the secretion of insulin.
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This question is part of the following fields:
- Medicine
- Neurology
-
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Question 71
Correct
-
Which caspase is part of both the intrinsic and extrinsic apoptotic pathways?
Your Answer: Caspase-3
Explanation:Once initiator caspases are activated in both the intrinsic and extrinsic pathway, they produce a chain reaction, activating several other executioner caspases (Caspase 3, Caspase 6 and Caspase 7).
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 72
Incorrect
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Question 73
Correct
-
With regard to X-linked disorders which of the following are true:
Your Answer: X linked recessive disorders usually present in males and only very rarely present in homozygous females
Explanation:X linked disorders are more common in males as they only need one mutated copy of the X chromosome to manifest the disease with full severity while the females need two X chromosomes to manifest the disease, even with one defected X chromosome the severity is less than that seen in males.
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This question is part of the following fields:
- Genetics
- Medicine
-
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Question 74
Correct
-
Anti-gastroesophageal reflux mechanisms include the following except:
Your Answer: Peristaltic movements of the oesophagus
Explanation:The lower oesophageal sphincter contracts preventing reflux of acid into the oesophagus. The sling muscles of the stomach, the crura of the diaphragm and the phreno-oesophageal ligament all play an important role in constricting the lower portion of the oesophagus and preventing reflux. Peristaltic movements do not stop the acid reflux.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 75
Correct
-
The blood supply to the greater curvature of the stomach is via the:
Your Answer: Right and left gastro-epiploic arteries
Explanation:The blood supply to the greater curvature of the stomach is via the left and the right gastro-epiploic arteries branching from the splenic artery near the hilum.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 76
Correct
-
Which vaso metabolite decreases coronary blood flow?
Your Answer: Endothelin
Explanation:Decreased O2, increased CO2, lactate, prostaglandins, adenine nucleotides, adenosine, H+, K+ and cyanide produce vasodilation and thus an increase in coronary blood flow.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 77
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.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 78
Correct
-
In paralytic ileus the following are true except:
Your Answer: Opioid blocking drugs will exacerbate the symptoms
Explanation:Paralytic ileus causes adynamic intestinal obstruction or decreased peristalsis and the most common reason being postoperative ileus. Opioid drugs like morphine are given for pain management and cause decreased peristalsis in the gut resulting in constipation. Theoretically opioid blocking drugs or opioid antagonists can increase peristalsis and can alleviate paralytic ileus symptoms.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 79
Correct
-
The choroid plexus:
Your Answer: All are true
Explanation:The choroid plexus is a vascular structure found in all cerebral ventricles. The functional unit of the choroid plexus, composed of a capillary, enveloped by a layer of differentiated ependymal epithelium. Unlike the capillaries that form the blood-brain barrier, choroid plexus capillaries are fenestrated and have no tight junctions. The endothelium, therefore, does not form a barrier to the movement of small molecules. Instead, the blood-CSF barrier at the choroid plexus is formed by the epithelial cells and the tight junctions that link them.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 80
Incorrect
-
What is the effect of catecholamines (i.e. increased heart rate) on the pressure volume loop?
Your Answer: Shifts the diastolic pressure curve to the right
Correct Answer: Shifts the diastolic pressure curve upward and leftward
Explanation:Catecholamines have a positive ionotropic and chronotropic effect on the heart. The ventricles develop greater tension during systole resulting in an increase in the stroke volume. The increase in stroke volume results in a decrease in the end diastolic volume. This pushes the loop towards the left and upwards.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 81
Correct
-
A 22 year old nulliparous female presents with shortness of breath. She has a history of recurrent deep vein thrombosis. Complete blood count and clotting screen reveals the following results:Hb: 12.4 g/dl Plt: 137 WBC: 7.5*109/l PT: 14 secs APTT: 46 secs Which of the following would be the most likely diagnosis?
Your Answer: Antiphospholipid syndrome
Explanation:The combination of APTT and low platelets with recurrent DVTs make antiphospholipid syndrome the most likely diagnosis.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 82
Incorrect
-
Which of the following involving the scalp may produce alopecia (hair loss)?
Your Answer: Seborrheic dermatitis
Correct Answer: Discoid lupus erythematosus
Explanation:Causes of hair loss include:
- Dissecting cellulitis
- Fungal infections (such as tinea capitis)
- Folliculitis
- Secondary syphilis
- Demodex folliculorum
- Lupus erythematosus (hair loss may be permanent due to scarring of the hair follicles).
Psoriasis and seborrheic dermatitis commonly involve the scalp but do not produce hair loss.
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This question is part of the following fields:
- Dermatology
- Medicine
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Question 83
Incorrect
-
The primary auditory cortex is:
Your Answer: Brodmann area 44
Correct Answer: Brodmann area 41
Explanation:A Brodmann area in the brain is defined by cytoarchitecture, histology and organization of cells:Primary Sensory 3,1,2Primary Motor 4Premotor 6Primary Visual 17Primary Auditory 41Brocas 44
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This question is part of the following fields:
- Medicine
- Neurology
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Question 84
Correct
-
A 55 year old cardiac patient is comfortable at rest but heavy housework results in fatigue, palpitations or dyspnoea. What New York Heart Association class best describes the severity of their disease?
Your Answer: NYHA Class II
Explanation:New York Heart Association functional classification:
Class I: no limitation is experienced in any activities; there are no symptoms from ordinary activities.
Class II: slight, mild limitation of activity; the patient is comfortable at rest or with mild exertion.
Class III: marked limitation of any activity; the patient is comfortable only at rest.
Class IV: any physical activity brings on discomfort and symptoms occur at rest.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 85
Correct
-
A 47 year old woman presents with joint pains and a history of recurrent infections over the past few months. Labs reveal a positive rheumatoid factor and low white cell count. Given the likely diagnosis, which of the following features would be present in her case?
Your Answer: Splenomegaly
Explanation:Felty syndrome is a severe subtype of seropositive Rheumatoid arthritis. Clinical triad consists of arthritis, splenomegaly, and neutropenia (leads to an increased risk of recurrent bacterial infections). Other symptoms include skin ulcers of the lower limbs (indicating vasculitis), hepatomegaly, fever, and chest pain (indicating pleuritis or pericarditis). It is associated with increased risk of developing non-Hodgkin lymphoma.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 86
Incorrect
-
Which is primarily responsible for the conversion of T4 to T3 in the periphery?
Your Answer: Deiodinase 2
Correct Answer: Deiodinase 1
Explanation:Type 1 iodothyronine deiodinase, also known simply as deiodinase 1, is an enzyme which can produce both triiodothyronine (active form) or inactivate metabolites from T4. It is responsible for almost 80% of the conversion of peripheral T4 to T3. Iodothyronine deiodinases are not to be confused with iodotyrosine deiodinases, which are also part of the deiodinase enzymes.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 87
Correct
-
Which of the following are true when it comes to tumour suppressor genes:
Your Answer: All of the options are true
Explanation:All of the above mentioned statements are true regarding tumour suppressor genes. Tumour suppressor genes generally follow the two-hit hypothesis, which implies that both alleles that code for a particular protein must be affected before an effect is manifested.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 88
Correct
-
One of the cells of the bone marrow that are responsible for forming the various forms of differentiated blood cells are called?
Your Answer: Hematopoietic stem cell
Explanation:Hematopoietic stem cells (HSCs) or hemocytoblasts are the stem cells that give rise to all the other blood cells through the process of haematopoiesis. They are derived from mesoderm and located in the red bone marrow, which is contained in the core of most bones.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 89
Correct
-
Where is most of the filtered sodium reabsorbed?
Your Answer: Proximal tubule
Explanation:Renal reabsorption of sodium (Na+) is a part of renal physiology. It uses Na-H antiport, Na-glucose symport, sodium ion channels (minor). It is stimulated by angiotensin II and aldosterone, and inhibited by atrial natriuretic peptide. Most of the reabsorption (65%) occurs in the proximal tubule.
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This question is part of the following fields:
- Medicine
- Renal
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Question 90
Correct
-
An 18 year old girl presents with short history of marked, right hip pain and an associated limp. She has a history of acute lymphoblastic leukaemia for which she completed treatment for last six months.
Your Answer: Avascular necrosis of the femoral head
Explanation:Avascular necrosis (AVN) of the femoral head is a pathological process that results from disruption of the blood supply to the bone and occurs most commonly in the femoral epiphysis. Patients usually present with pain and limited joint motion. The mechanism involves impaired circulation to a specific area that ultimately becomes necrotic. AVN is most frequently associated with high doses of oral and intravenous corticosteroids and prolonged duration of therapy. Cancer patients receiving chemotherapy are usually also treated with corticosteroids.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 91
Correct
-
What is the effect of oxytocin on the breast?
Your Answer: Milk ejection
Explanation:Oxytocin is a peptide hormone and neuropeptide, produced by the hypothalamus and released by the posterior pituitary. It causes the milk ejection or let-down reflex, causing the milk to be transported to the subareolar sinuses, allowing it to be released through the nipple. This response is initiated by the act of suckling by the baby, but it can be conditioned to be triggered by different stimuli.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 92
Correct
-
Which one of the following skin disorders is least commonly associated with hypothyroidism?
Your Answer: Pretibial myxoedema
Explanation:Pretibial myxoedema is an infiltrative dermopathy, resulting as a rare complication of Graves’ disease (hyperthyroidism) and very occasionally occurs in non-thyrotoxic Graves’ disease and Hashimoto’s thyroiditis.
Hypothyroidism typically presents with symptoms such as dry skin, brittle hair, and thinning of the outer third of the eyebrows. While skin conditions like dryness and hair changes are common in hypothyroidism due to reduced metabolic activity, acne is also not typically associated with it.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 93
Correct
-
Which of the following takes place during fasting
Your 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.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 94
Correct
-
What is the primary cause of ketoacidosis in Type 1 diabetes?
Your 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 β-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.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 95
Correct
-
In Jugular vein pressure the “a” wave represents?
Your 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).
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 96
Incorrect
-
When during the cell cycle does DNA replication occur?
Your Answer: Mitosis
Correct Answer: S phase
Explanation:The S phase is known as the synthesis phase. During this phase DNA will begin to replicated, as well as the synthesis of the centrosomes and associated proteins.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 97
Incorrect
-
Select the correct statement regarding portal hypertension.
Your Answer: Portal blood flow through the liver is increased.
Correct Answer: The total vascular resistance of the hepatic sinusoids is increased.
Explanation:Portal hypertension is increased blood pressure within the portal venous system. This happens mainly due to liver damage which increases the vascular resistance of hepatic sinusoids by interfering with the normal blood flow. Portal blood pressure increases and flow through the liver decreases. Normal portal venous pressure is between 5-10 mmHg and in portal hypertension it’s usually more than 10 mmHg. This high pressure can cause accumulation of fluid in the peritoneal cavity known as ascites. To overcome the pressure, the portal vein starts to drain blood to systemic circulation via porto-systemic shunts. The connection between the portal vein and inferior vena cava is known as the porto caval shunt. Due to damaged hepatocytes, detoxification of substances absorbed in the intestine is impaired and the former shunt mixes non-detoxified blood with the systemic circulation. These toxic substances may affect neurons causing hepatic encephalopathy which is a major complication of portal hypertension.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
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Question 98
Correct
-
Di and tri peptides are absorbed via a different mechanism as amino acids, this is due to the working of which transporter?
Your Answer: PEPT 1
Explanation:GLUT and SGLT are glucose transporters. Peptides which are longer that four amino acids are not absorbed. There is abundant absorption of di and tri peptidases in the small intestine. They are absorbed into the epithelial cells of the small intestine via a transporter called PepT1 by co-transport with H+ ions.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 99
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: Lisinopril
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.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 100
Incorrect
-
Which of the following diseases have antibodies available for treatment of the condition.
Your Answer: Rabies
Correct Answer: None of these
Explanation:There is no specific treatment for hepatitis A. Recovery from symptoms following infection may be slow and may take several weeks or months. The hepatitis A vaccine is effective for prevention and appears to be effective for life.Acute hepatitis B infection does not usually require treatment and most adults clear the infection spontaneously. Early antiviral treatment may be required in fewer than 1% of people, whose infection takes a very aggressive course (fulminant hepatitis) or who are immunocompromised. Although none of the available drugs can clear the infection, they can stop the virus from replicating, thus minimizing liver damage.There is no specific treatment for measles. Most people with uncomplicated measles will recover with rest and supportive treatment. In developed countries, children are immunized against measles at 12 months, generally as part of a three-part MMR vaccine (measles, mumps, and rubella). The vaccination is generally not given before this age because such infants respond inadequately to the vaccine due to an immature immune system. Treatment after rabies exposure can prevent the disease if administered promptly, generally within 10 days of infection. The Centres for Disease Control and Prevention recommends people receive one dose of human rabies immunoglobulin (HRIG) and four doses of rabies vaccine over a 14-day period.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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SESSION STATS - PERFORMANCE PER SPECIALTY
