-
Question 1
Incorrect
-
Where is the carotid sinus located?
Your Answer: After the bifurcation of the carotid artery, on the external carotid
Correct Answer: After the bifurcation of the carotid artery, on the internal carotid
Explanation:The carotid sinus is a small dilation in the internal carotid artery just above its bifurcation into the external and internal carotid branch. Baroreceptors are present at this dilation.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 2
Incorrect
-
Regarding the structure of the 3 pituitary glycoprotein hormones FSH, LH, and TSH, which of the following is true about the α- and β-subunits of each hormone?
Your Answer: The α-subunits are not interchangeable
Correct Answer: Maximal physiological activity occurs only on their combination
Explanation:Glycoprotein hormones (GPHs) are the most complex molecules that function as hormones. They each consist of two different subunits, α and β, which are non-covalently associated. The combination of these subunits results in an increase in their activity and β structure.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 3
Incorrect
-
In most somatic cells telomeres progressively shorten as:
Your Answer: The cell ages
Correct Answer: The cell divides
Explanation:Telomere length shortens with age. Progressive shortening of telomeres leads to senescence, apoptosis, or oncogenic transformation of somatic cells, affecting the health and lifespan of an individual. Telomeres prevent the chromosomes from shortening and prevent the coding portion of the DNA from being lost, thus allowing the cell to replicate indefinitely. During replication telomeres may be lost resulting in cell death.
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 4
Correct
-
Select the correct statement regarding terminal bronchioles:
Your Answer: Terminal bronchioles form part of the conducting zone
Explanation:Bronchioles divide into even smaller bronchioles, called terminal bronchioles, which are 0.5mm or less in diameter. Terminal bronchioles in turn divide into smaller respiratory bronchioles which divide into alveolar ducts. Terminal bronchioles mark the end of the conducting division of air flow in the respiratory system while respiratory bronchioles are the beginning of the respiratory division where actual gas exchange takes place. Terminal bronchioles are lined with simple cuboidal epithelium containing club cells. Terminal bronchioles contain a limited number of ciliated cells and no goblet cells. Club cells are non-ciliated, rounded protein secreting cells. Their secretions are a non-stick, proteinaceous compound (surfactant) to maintain the airway in the smallest bronchioles.
-
This question is part of the following fields:
- Medicine
- Respiratory
-
-
Question 5
Correct
-
In a 70 kg male, the approximate volumes (litres) of water in the different compartments mentioned (intracellular, interstitial, vascular) are:
Your 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 6
Correct
-
Which vitamin plays a major role in the metabolism of many amino acids?
Your Answer: Vitamin B6
Explanation:Vitamin B6 is part of the vitamin B group, and its active form, pyridoxal 5′-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 7
Correct
-
A 45 year old man presents with fever, malaise, weight loss and myalgias that have been occurring for a month. You suspect polyarteritis nodosa and arrange for some lab investigations. Which of the following abnormality would most likely be present?
Your Answer: Elevated creatinine
Explanation:People with polyarteritis nodosa often exhibit anaemia of chronic disease. Leucocytosis and eosinophilia may also be present. ANCA is only rarely positive. As polyarteritis nodosa affects the kidneys as well, the creatinine is elevated in most cases.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 8
Incorrect
-
A 75-year-old man has presented to the clinic with a complaint of disturbed sleep. The physician has prescribed temazepam. Which of the following best describes the mechanism of action of this drug?
Your Answer: Inhibits the effect gamma-aminobutyric acid
Correct Answer: Enhances the effect of gamma-aminobutyric acid
Explanation:Temazepam is an orally available benzodiazepine used in the therapy of insomnia. The soporific activity of the benzodiazepines is mediated by their ability to enhance gamma-aminobutyric acid (GABA) mediated inhibition of synaptic transmission through binding to the GABA-A receptor.The recommended initial dose for insomnia is 7.5 mg before bedtime, increasing as needed to a maximum dose of 30 mg. The most common side effects of temazepam are dose-related and include daytime drowsiness, lethargy, ataxia, dysarthria, and dizziness.Tolerance develops to these side effects, but tolerance may also develop to the effects on insomnia.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 9
Correct
-
Which cells secrete insulin?
Your Answer: B cells of the pancreatic islets
Explanation:Insulin is synthesised and stored by the B cells of the pancreatic islets (70% of islet cells), glucagon is synthesised and stored in the A cells (20%) and somatostatin is synthesised and stored in the D cells (10%).
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 10
Correct
-
Which of the following is a form of synaptic plasticity?
Your Answer: Working memory
Explanation:Synaptic plasticity is an important neurochemical foundation of working memory and generation of memory. Synaptic plasticity is the ability of synapses to strengthen or weaken over time in response to increases or decreases in their activity.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 11
Incorrect
-
Where do the meningeal veins lie?
Your Answer: Exosteal layer of the dura
Correct Answer: Endosteal layer of the dura
Explanation:Meningeal veins lie in the endosteal layer of the dura. The veins lie lateral to the arteries.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 12
Correct
-
The following is true about the carotid arterial supply to the brain:
Your Answer: Following carotid occlusion, precapillary anastomoses are unable to prevent infarction
Explanation:The brain has two sources of blood supply; the internal carotid arteries which are the anterior segment or the main artery that supplies the anterior portion of the brain, and the vertebral arteries which is the posterior segment which supplies the posterior portion of the brain. The internal carotid arteries branch and form two major arteries anterior and middle cerebral arteries. The right and left vertebral arteries fuse together at the level of the pons on the anterior surface of the brainstem to form the midline basilar artery. The basilar artery joins the blood supply from the internal carotids in an arterial ring at the base of the brain called the circle of Willis. The anterior and posterior communicating arteries conjoin the two major sources of cerebral vascular supply via the circle of Willis improving the chances of any region of the brain continuing to receive blood if one of the major arteries becomes occluded.
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 13
Incorrect
-
The superior orbital fissure is the site of entry/exit for which of the following group of nerves?
Your Answer: CN III, IV, V2, VI
Correct Answer: CN III, IV, V1, VI
Explanation:The superior and inferior divisions of oculomotor nerve (III), trochlear nerve (IV), lacrimal, frontal and nasociliary branches of ophthalmic V1 and the abducens nerve (VI)
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 14
Correct
-
Question 15
Correct
-
Which one of these features is typical of dermatomyositis?
Your Answer: Gottron's papules over knuckles of fingers
Explanation:Dermatomyositis is a long-term inflammatory disorder which affects muscles. Its symptoms are generally a skin rash and worsening muscle weakness in the proximal muscles (for example, the shoulders and thighs) over time. These may occur suddenly or develop over months. Other symptoms may include weight loss, fever, lung inflammation, or light sensitivity. Complications may include calcium deposits in muscles or skin.The skin rash may manifest as aheliotrope (a purplish color) or lilac, but may also be red. It can occur around the eyes along with swelling, as well as the upper chest or back ( shawl sign) or V-sign above the breasts and may also occur on the face, upper arms, thighs, or hands. Another form the rash takes is called Gottron’s sign which are red or violet, sometimes scaly, slightly raised papules that erupt on any of the finger joints (the metacarpophalangeal joints or the interphalangeal joints)
-
This question is part of the following fields:
- Dermatology
- Medicine
-
-
Question 16
Correct
-
In a patient with prostate cancer, what is the mechanism by which goserelin acts?
Your Answer: GnRH agonist
Explanation:Androgen deprivation therapy (ADT) for prostate cancer:Goserelin (Zoladex) is a synthetic gonadotropin-releasing hormone (GnRH) analogue; chronic stimulation of goserelin results in suppression of LH, FSH serum levels thereby preventing a rise in testosterone.Dosage form: 3.6 mg/10.8mg implants.Adverse effects include flushing, sweating, diarrhoea, erectile dysfunction, less commonly, rash, depression, hypersensitivity, etc.
-
This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 17
Correct
-
Which of the following involving the scalp may produce alopecia (hair loss)?
Your 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.
-
This question is part of the following fields:
- Dermatology
- Medicine
-
-
Question 18
Correct
-
The infoldings or spaces between the bases of the villi are known as
Your Answer: Crypts of Lieberkühn
Explanation:An intestinal gland (also crypt of Lieberkühn and intestinal crypt) is a gland found in the intestinal epithelium lining of the small intestine and large intestine (colon) between the villi.
-
This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 19
Incorrect
-
The telomerase is capable of adding several more repeats of telomeres at which end of the guanosine rich region.
Your Answer: 4th end
Correct Answer: 3rd end
Explanation:Telomerase is a reverse transcriptase that uses the RNA template to synthesize DNA in the 5th-3rd direction resulting in extension of the 3rd end and then translocates it to the newly synthesized end. The GT rich strand is thus elongated.
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 20
Correct
-
Question 21
Correct
-
The nucleus ambiguus:
Your Answer: Regulates swallowing, phonation and parasympathetic supply to the heart via CN IX, X and XI
Explanation:Nucleus Ambiguus is a group of large motor neurons found deep in the medullary reticular formation. It contains cell bodies of nerves that are responsible for the innervation of muscles of speech and swallowing which are located in the soft palate, pharynx and larynx. Additionally, it contains cholinergic preganglionic parasympathetic neurons of the heart via CN X, IX and XI
-
This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 22
Incorrect
-
A 60 year old male presents with thickened patches of skin over his knuckles and extensor surfaces that are consistent with Gottron's papules. Results reveal an elevated creatine kinase. Diagnosis of dermatomyositis is suspected. Which of the following autoantibody is most specific for this condition?
Your Answer: Anti-Jo-1 antibodies
Correct Answer: Anti-Mi-2 antibodies
Explanation:Anti–Mi-2 antibodies are highly specific for dermatomyositis, but sensitivity is low; only 25% of patients with dermatomyositis demonstrate these antibodies. A positive antinuclear antibody (ANA) finding is common in patients with dermatomyositis, but is not necessary for diagnosis. Anti-Jo-1 antibodies are mostly associated with polymyositis. Anti Scl-70 antibodies and anti centromere antibodies are most commonly found in systemic scleroderma.
-
This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 23
Correct
-
What is the isolated effect of B2 stimulation on the coronaries?
Your Answer: Vasodilatation
Explanation:Norepinephrine and epinephrine are agonists for all adrenergic receptor subtypes, although with varying affinities. Based on their physiology and pharmacology, adrenergic receptors have been divided into two principal types: alpha and beta. These types have been further differentiated into alpha-1, alpha-2, b1, and b2 receptors.
Alpha-1 Receptors are located on postsynaptic cells in smooth muscle and elicit vasoconstriction.
Alpha-2 receptors are localized on presynaptic membranes of postganglionic nerve terminals that synthesize norepinephrine. When activated by catecholamines, alpha-2 receptors act as negative feedback controllers, inhibiting further norepinephrine release.
Activation of myocardial b1 receptors stimulates the rate and strength of cardiac contraction, and consequently increases cardiac output. b1 Receptor activation also stimulates renin release from the kidney. Another class of antihypertensive agents acts by inhibiting b1 receptors.
Activation of b2 receptors by epinephrine relaxes vascular smooth muscle and results in vasodilation.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 24
Correct
-
The coronary sinus drains into the:
Your Answer: Right atrium
Explanation:The coronary sinus drains into the right atrium. Most of the venous blood returns to the heart via the coronary sinus and the anterior cardiac veins. Apart from these there are other vessels that drain directly into the heart chambers.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 25
Incorrect
-
“Ploidy” is a term used to refer to the number of chromosomes in cells. Cancer cells are commonly:
Your Answer: Tetraploidy
Correct Answer: Aneuploidy
Explanation:Cancer cells most commonly undergo disordered cell growth and cell division. This results in an additional number of chromosomes called aneuploidy. This is a characteristic of cancer cells along with variation in differentiation of the cells.
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 26
Correct
-
The largest energy reserves among both lean and obese subjects are from?
Your Answer: Fatty acids
Explanation:The energy required for sustained exercise is provided by the oxidation of two fuels, glucose stored as glycogen in the liver and muscle, and long-chain fatty acids, stored as adipose tissue triglycerides. The latter provides the largest energy reserve in the body.
-
This question is part of the following fields:
- Medicine
- Metabolism
-
-
Question 27
Incorrect
-
ADH causes?
Your Answer: Decreased permeability of the collecting ducts to water
Correct Answer: Increased permeability of the collecting ducts to water
Explanation:Vasopressin (ADH) has three main effects:1. Increasing the water permeability of distal convoluted tubule and collecting duct cells in the kidney, thus allowing water reabsorption and excretion of more concentrated urine.2. Increasing permeability of the inner medullary portion of the collecting duct to urea by regulating the cell surface expression of urea transporters.3. Acute increase of sodium absorption across the ascending loop of Henle.
-
This question is part of the following fields:
- Medicine
- Renal
-
-
Question 28
Incorrect
-
The chromosomes that principally encode for proteins or RNA molecules involved in mitochondrial function are found:
Your Answer: In the mitochondria of the cell
Correct Answer: In the nucleus of each diploid cell
Explanation:While mitochondria have their own small circular DNA (mtDNA) that encodes some of the proteins and RNAs required for mitochondrial function, the majority of proteins involved in mitochondrial function are encoded by nuclear DNA. These nuclear genes are transcribed in the nucleus and then translated into proteins in the cytoplasm. The proteins are subsequently imported into the mitochondria.
Therefore, the correct answer is:
- In the nucleus of each diploid cell
-
This question is part of the following fields:
- Genetics
- Medicine
-
-
Question 29
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 30
Correct
-
In both innate and humoral immunity, receptors involved recognize:
Your Answer: The shape of the antigen
Explanation:Antigen receptors recognize the shape of the antigen. They identify specific epitopes and are found on T cells.
-
This question is part of the following fields:
- Immunology
- Medicine
-
SESSION STATS - PERFORMANCE PER SPECIALTY
