-
Question 1
Incorrect
-
Which cell type functions as the critical bridge between innate and adaptive immune systems, by activating naïve T lymphocytes?
Your Answer: Natural killer cells
Correct Answer: Dendritic cells
Explanation:Dendritic cells are antigen presenting cells. They express class II MHC and T cell co-stimulatory molecules. They bind antigens and present them to native T cells and in the process activate the specific T cell against that antigen.
-
This question is part of the following fields:
- Immunology
- Physiology
-
-
Question 2
Incorrect
-
The enzyme responsible for telomeres maintaining their length after cell division is called:
Your Answer: Telomere restrictedase
Correct Answer: Telomerase reverse transcriptase
Explanation:Telomerase is a reverse transcriptase that uses the RNA template to synthesize DNA in the 5′-3′ direction resulting in extension of the already 3′ 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
- Physiology
-
-
Question 3
Correct
-
Which of the following vitamin deficiencies is associated with xerophthalmia?
Your Answer: Vitamin A
Explanation:Xerophthalmia caused by a severe vitamin A deficiency is described by pathologic dryness of the conjunctiva and cornea. The conjunctiva becomes dry, thick and wrinkled. If untreated, it can lead to corneal ulceration and ultimately to blindness as a result of corneal damage.
-
This question is part of the following fields:
- Haematology
- Physiology
-
-
Question 4
Incorrect
-
Majority of gastrinomas are found in the:
Your Answer: Pancreas
Correct Answer: Duodenum
Explanation:A gastrinoma is a tumour in the pancreas or duodenum that secretes excess of gastrin leading to ulceration in the duodenum, stomach and the small intestine. It is usually found in the duodenum, although it may arise in the stomach or pancreas. Those occurring in the pancreas have a greater potential for malignancy. Most gastrinomas are found in the gastrinoma triangle; this is bound by the junction of cystic and common bile ducts, junction of the second and third parts of the duodenum, and the junction of the neck and body of the pancreas.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 5
Incorrect
-
Lipid- lowering drugs like Lovastatin reduce cholesterol synthesis by inhibiting which enzyme?
Your Answer: Lipoprotein lipase
Correct Answer: HMG-CoA reductase
Explanation:Statins, also known as HMG-CoA reductase inhibitors, are a class of lipid-lowering medications. Statins have been found to reduce cardiovascular disease (CVD) and mortality in those who are at high risk.
-
This question is part of the following fields:
- Metabolism
- Physiology
-
-
Question 6
Incorrect
-
Which dorsal (sensory) root is responsible for umbilical area sensation?
Your Answer: L5
Correct Answer: T10
Explanation:The area of skin supplied by one nerve is called a dermatome. T10 supplies sensory neurons to the area of the umbilicus. C3 and C4 supply the neck and the shoulder, T4 supplies the dermatome at the level of the nipple, S3 supplies the inguinal region and L5 supplies the lateral aspect of the leg and the medical aspect of the dorsum of the feet plus the first 3 toes.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 7
Correct
-
Which of the following antiarrhythmic drugs may be used in the treatment of long QT syndrome?
Your Answer: Atenolol
Explanation:Beta-blockers are the mainstay of treatment in long QT syndrome. Implantable cardioverter-defibrillators are the most effective treatment in genotypes with a high risk of recurrence.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 8
Incorrect
-
Which part of the cerebellum is primarily responsible for equilibrium and eye movements?
Your Answer: Lateral hemispheric portions
Correct Answer: Vestibulocerebellum
Explanation:The vestibulocerebellum develops at the same time as the vestibular apparatus in the inner ear. Its regulates balance between agonist and antagonist muscle contractions of the spine, hips, and shoulders during rapid movements.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 9
Incorrect
-
In the body what are fatty acids broken down to?
Your Answer: Carnitine
Correct Answer: Acetyl Co A
Explanation:Fatty acids are broken down into acetyl Co A. The acetyl-CoA produced by beta oxidation enters the citric acid cycle in the mitochondrion by combining with oxaloacetate to form citrate.
-
This question is part of the following fields:
- Cell Biology
- Physiology
-
-
Question 10
Incorrect
-
Which of the following hormones cause negative feedback on the CRH/ACTH axis?
Your Answer: Aldosterone
Correct 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.
-
This question is part of the following fields:
- Endocrinology
- Physiology
-
-
Question 11
Incorrect
-
What is the protective hexametric sequence at the ends of chromosomes called?
Your Answer: Intron
Correct Answer: Telomere
Explanation:Telomeres are non coding DNA plus proteins that are found at the end of the linear chromosomes. They maintain the integrity of the chromosomes and prevent their shortening.
-
This question is part of the following fields:
- Genetics
- Physiology
-
-
Question 12
Incorrect
-
After eating a meal containing a moderate amount of fat, which percentage of fat is likely to be absorbed from the GIT in an adult?
Your Answer: 50%
Correct Answer: 95%
Explanation:About 95% of dietary fat is absorbed.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 13
Incorrect
-
Which of the following supplies the AV node?
Your Answer: Left coronary artery
Correct Answer: Right coronary artery
Explanation:The AV node is supplied by the right coronary artery near the origin of the posterior IV artery.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 14
Correct
-
Relaxation of the cardiac muscle at the actin-myosin cross bridges is initiated by binding of which molecule to the exposed site on the myosin.
Your Answer: ATP
Explanation:A crossbridge is a myosin projection, consisting of two myosin heads, that extends from the thick filaments. Each myosin head has two binding sites: one for ATP and another for actin. The binding of ATP to a myosin head detaches myosin from actin, thereby allowing myosin to bind to another actin molecule. Once attached, the ATP is hydrolysed by myosin, which uses the released energy to move into the cocked position whereby it binds weakly to a part of the actin binding site.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 15
Incorrect
-
Which of the following associations is false?
Your Answer: Facial nerve – stylomastoid foramen
Correct Answer: Mandibular nerve – foramen lacerum
Explanation:– The olfactory nerves pass through the cribriform plate- The maxillary division of the trigeminal nerve passes through the foramen rotundum- The facial nerve passes through the stylomastoid foramen- The mandibular division of the trigeminal nerve pass through the foramen ovale- The glossopharyngeal nerve passes through the jugular foramen.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 16
Correct
-
A 28-year-old patient is intubated and has a central venous catheter inserted after being diagnosed with septic shock. You keep track of her central venous pressure. The normal value for central venous pressure is which of the following?
Your Answer: 0-8 cmH 2 O
Explanation:The pressure measured in the right atrium or superior vena cava is known as central venous pressure (CVP). In a spontaneously breathing subject, the usual CVP value is 0-8 cmH2O (0-6 mmHg). At the conclusion of expiration, the CVP should be measured with the patient resting flat. The catheter’s tip should be at the intersection of the superior vena cava and the right atrium. An electronic transducer is installed and zeroed at the level of the right atrium to measure it (usually in the 4th intercostal space in the mid-axillary line). CVP is a good predictor of preload in the right ventricle. Hypovolaemia is indicated by a volume challenge of 250-500 mL crystalloid eliciting an increase in CVP that is not sustained for more than 10 minutes. CVP is influenced by a number of factors, including: Mechanical ventilation (and PEEP) Pulmonary hypertension Pulmonary embolism Heart failure Pleural effusion Decreased cardiac output Cardiac tamponade CVP is reduced by the following factors: Distributive shock Negative pressure ventilation Hypovolaemia Deep inhalation
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 17
Correct
-
Question 18
Incorrect
-
In blistering dermatological disorders e.g.. Pemphigus, which junctions are attacked by autoantibodies?
Your Answer: Zonula adherens
Correct Answer: Desmosomes
Explanation:Pemphigus is an autoimmune disease caused by antibodies directed against both desmoglein 1 and desmoglein 3 present in desmosomes. Loss of desmosomes results in loss of cohesion between keratinocytes in the epidermis, and a disruption of the barrier function served by intact skin. The process is classified as a type II hypersensitivity reaction
-
This question is part of the following fields:
- Cell Biology
- Physiology
-
-
Question 19
Incorrect
-
Which of the following features is least commonly seen in Gitelman’s syndrome?
Your Answer: Hypocalciuria
Correct Answer: Hypertension
Explanation:Gitelman syndrome is an autosomal recessive kidney disorder characterized by hypokalaemia metabolic alkalosis with hypocalciuria, and hypomagnesemia. In contrast to patients with Gordon’s syndrome, those suffering from Gitelman’s syndrome are generally normotensive or hypotensive.
-
This question is part of the following fields:
- Endocrinology
- Physiology
-
-
Question 20
Incorrect
-
Question 21
Incorrect
-
Which of the following is not innervated by the parasympathetic nerve supply?
Your Answer: Salivary gland
Correct Answer: Radial muscle of iris
Explanation:The sphincter pupillae is supplied by the parasympathetic fibers from the Edinger Westphal nucleus of the oculomotor nerve. The dilator pupillae (radial muscle) is supplied by the postganglionic fibers of the superior cervical sympathetic ganglion. The parasympathetic nerve supply to the salivary glands originate in the parasympathetic nucleus of the facial nerve (superior salivatory nucleus) and the glossopharyngeal nerve (inferior salivatory nucleus). The parasympathetic preganglionic fibers originate in the dorsal nucleus of the vagus nerve and descend into the thorax in the vagus nerve. The fibers terminate by synapsing with postganglionic neurons in the cardiac plexuses. Postganglionic fibers terminate on the sinoatrial and atrioventricular nodes and on the coronary arteries Parasympathetic supply to the stomach is via the vagus nerve.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 22
Incorrect
-
Most of the venous blood returns to the heart through the:
Your Answer: Left anterior descending artery
Correct Answer: Coronary sinus and anterior cardiac veins
Explanation:Most of the venous blood returns to the heart via the coronary sinus and the anterior cardiac veins which drain into the right atrium.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 23
Incorrect
-
Depolarization spreads rapidly through cardiac muscle fibers because of the presence of:
Your Answer: Zonula occludens
Correct Answer: Gap junctions
Explanation:The cardiac muscles have gap junctions in between the cells. They allow for the formation of low resistance passages, which allow ions to diffuse through every muscle fiber rapidly and result in the cardiac muscles functioning as a syncytium, without any protoplasmic bridges involved.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 24
Correct
-
What is the most abundant hormone release by the thyroid?
Your Answer: T4
Explanation:T3 and T4 are the two tyrosine-based hormones produced and secreted by the thyroid gland. Although T3 is the active form of the hormone, and thus, it is much more potent; T4 is the most abundant hormone secreted by the thyroid (93% of the total thyroid secretion) and it also has a longer half life since it binds to proteins much more strongly.
-
This question is part of the following fields:
- Endocrinology
- Physiology
-
-
Question 25
Incorrect
-
In both innate and humoral immunity, receptors involved recognize:
Your Answer: The specific chemical composition of the antigen
Correct 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
- Physiology
-
-
Question 26
Incorrect
-
The process whereby bacterial products interact with plasma factors and cells to produce agents that attract neutrophils to an infected area is called:
Your Answer: Degranulation
Correct Answer: Chemotaxis
Explanation:During an inflammatory process many cytokines are produced that act as chemokines to attract neutrophils to the site of inflammation. These include bacterial products, IL-8, C5a and LTB4.
-
This question is part of the following fields:
- Immunology
- Physiology
-
-
Question 27
Correct
-
Pre-oxygenation is done prior to intubation to extend the ‘safe apnoea time’. Which lung volume or capacity is the most important store of oxygen in the body?
Your Answer: Functional residual capacity
Explanation:The administration of oxygen to a patient before intubation is called pre-oxygenation and it helps extend the ‘safe apnoea time’. The Functional residual capacity (FRC) is the volume of gas that remains in the lungs after normal tidal expiration. It is the most important store of oxygen in the body. The aim of pre-oxygenation is to replace the nitrogen in the FRC with oxygen. Apnoea can be tolerated for longer periods before critical hypoxia develops if the FRC is large. Patients with reduced FRC reach critical hypoxia more rapidly.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 28
Incorrect
-
Inactive cellular marrow is called
Your Answer: Pink marrow
Correct Answer: Yellow marrow
Explanation:The two types of bone marrow are red marrow, which consists mainly of hematopoietic tissue, and yellow marrow, which is mainly made up of fat cells.
-
This question is part of the following fields:
- Haematology
- Physiology
-
-
Question 29
Incorrect
-
The cerebellum consists of which three cell layers?
Your Answer: Purkinje, stellate, basket
Correct Answer: Granular, purkinje, molecular
Explanation:The cerebellar cortex consist of 3 layers; the molecular layer, the granular cell layer and the Purkinje cell layer in the middle.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 30
Incorrect
-
Which of the following can trigger parietal cell secretion?
Your Answer: Lipase
Correct Answer: Gastrin
Explanation:The three agonists of parietal cell secretion are gastrin, acetylcholine and histamine. Parietal cells are responsible for the secretion of HCl and intrinsic factor.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 31
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:
- Neurology
- Physiology
-
-
Question 32
Incorrect
-
Bile contains:
Your Answer: Steroids, pigments, salts
Correct Answer: Bile acids, phosphatidylcholine, cholesterol
Explanation:The main components of bile include bile acids or bile salts, phospholipids; mainly phosphatidylcholine, cholesterol, bilirubin, inorganic salts; potassium, sodium and bicarbonate.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 33
Correct
-
The direct determinants of cardiac output are
Your Answer: Stroke volume and heart rate
Explanation:Cardiac output is classically defined alongside stroke volume (SV) and the heart rate (HR) as:Cardiac Output [L/min] = Stroke Volume [L/beat] x Heart Rate [beats/min]
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 34
Incorrect
-
Which of the following is an example of a ketone body?
Your Answer: Acetoacetyl CoA
Correct Answer: Acetoacetate
Explanation:Ketone bodies are three water-soluble molecules (acetoacetate, beta-hydroxybutyrate, and their spontaneous breakdown product, acetone) that are produced by the liver from fatty acids during periods of low food intake (fasting), carbohydrate restrictive diets, starvation, prolonged intense exercise, alcoholism or in untreated (or inadequately treated) type 1 diabetes mellitus.
-
This question is part of the following fields:
- Metabolism
- Physiology
-
-
Question 35
Incorrect
-
In a 30 year old male with hypertrophic obstructive cardiomyopathy (HOCM), which of the following is associated with increased risk of sudden death?
Your Answer: Asymmetrical septal hypertrophy
Correct Answer: Degree of left ventricular hypertrophy
Explanation:Hypertrophic cardiomyopathy (HCM) is a disease in which a portion of the myocardium (heart muscle) is enlarged without any obvious cause, creating functional impairment of the heart. It is the leading cause of sudden death in young athletes. Major risk factors for sudden death in individuals with HCM include prior history of cardiac arrest or ventricular fibrillation, spontaneous sustained ventricular tachycardia, family history of premature sudden death, unexplained syncope, left ventricular thickness greater than or equal to 30 mm, abnormal exercise blood pressure and unsustained ventricular tachycardia. The most strongly correlated is the degree of left ventricular hypertrophy (LVH).
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 36
Incorrect
-
Intrinsic Factor is released by,
Your Answer: Surface mucus cells
Correct Answer: Parietal cell
Explanation:Intrinsic factor (IF), also known as gastric intrinsic factor (GIF), is a glycoprotein produced by the parietal cells of the stomach. It is necessary for the absorption of vitamin B12 (cobalamin) later on in the small intestine.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 37
Incorrect
-
When during the cell cycle do the centrioles replicate?
Your Answer: Resting phase
Correct Answer: G1 phase
Explanation:During G1 phase the cell will prepare for cell division. All the organelles will start to duplicate in this phase and the cell will begin to grow whilst proteins are also synthesized.
-
This question is part of the following fields:
- Genetics
- Physiology
-
-
Question 38
Incorrect
-
Myocardium requires more oxygen to expel blood in:
Your Answer: A stenotic pulmonary valve
Correct Answer: A stenotic aortic valve
Explanation:In aortic valve stenosis, increased ventricular pressure Is needed to expel the blood into the aorta. Increased pressure means increased contractility hence increase O2 consumption by the heart muscles.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 39
Incorrect
-
Pressure across the wall of a flexible tube (the transmural pressure) increases wall tension and extends it. Which law best describes transmural pressure?
Your Answer: Fick’s law
Correct Answer: Laplace’s law
Explanation:The transmural pressure (pressure across the wall of a flexible tube) can be described by Laplace’s law which states that: Transmural pressure = (Tw) / r Where: T = Wall tension w = Wall thickness r = The radius A small bubble with the same wall tension as a larger bubble will contain higher pressure and will collapse into the larger bubble if the two meet and join. Fick’s law describes the rate of diffusion in a solution Poiseuille’s law is used to calculate volume of flow rate in laminar flow Darcy’s law describes the flow of a fluid through a porous medium. Starling’s law describes cardiac haemodynamics as it relates to myocyte contractility and stretch.
-
This question is part of the following fields:
- Cell Biology
- Physiology
-
-
Question 40
Incorrect
-
Vitamin K deficiency can be found in which of the following condition?
Your Answer: Intestinal bacterial overgrowth
Correct Answer: Cholestatic jaundice
Explanation:Vitamin K1-deficiency may occur by disturbed intestinal uptake (such as would occur in a bile duct obstruction), by therapeutic or accidental intake of a vitamin K1-antagonist such as warfarin, or, very rarely, by nutritional vitamin K1 deficiency.
-
This question is part of the following fields:
- Haematology
- Physiology
-
-
Question 41
Correct
-
Restriction fragment length polymorphisms/ Gene Knockout Mouse Models. All true except:
Your Answer: In knockout mouse models a gene is turned on through targeted mutation
Explanation:Yeast chromosomes cannot be used as a vector. All the rest are true. Vectors can be bacteria, viruses and plasmids. DNA ligase binds the DNA fragment to the host DNA after insertion. Fluorescence can be used to visualize them.
-
This question is part of the following fields:
- Genetics
- Physiology
-
-
Question 42
Incorrect
-
Direct conduction from the atrium to the ventricles is prevented by:
Your Answer: Intermodal pathways
Correct Answer: Annulus fibrosus
Explanation:The annulus fibrosus disconnects the syncytium complex. The atria are rapidly activated however the activation peters out when the insulating layer-the annulus fibrosus-is reached.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 43
Incorrect
-
Periodic fevers occur in humans with mutations in the gene for pyrin. Pyrin is a protein found in which one of the following cells?
Your Answer: B lymphocytes
Correct Answer: Neutrophils
Explanation:Pyrin, also known as marenostrin or TRIM20, is a protein encoded by the Mediterranean fever (MEFV) gene, causing the autoinflammatory disease familial Mediterranean fever (FMF). Pyrin produces an increased sensitivity to intracellular signals. It is produced mainly in neutrophils, which display an increased ratio of cells entering apoptosis when exposed to pyrin.
-
This question is part of the following fields:
- Endocrinology
- Physiology
-
-
Question 44
Incorrect
-
What is the normal duration of the ST segment?
Your Answer: 0.2 s
Correct Answer: 0.08 s
Explanation:The ST segment lies between the QRS complex and the T-wave. The normal duration of the ST segment is 0.08 s. ST-segment elevation or depression may indicate myocardial ischaemia or infarction.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 45
Incorrect
-
Which of the following statements is not true about mitochondrial chromosomes?
Your Answer: Are circular DNA molecules of approximately 16 500 base pairs, and every base-pair makes up part of the coding sequence
Correct Answer: Mitochondrial chromosomes play no role in the transmission of disease from generation to generation.
Explanation:All the above mentioned statements are true except that mitochondrial DNA is passed from the mother to the child. If the child inherits the defective mitochondrial gene it will manifest some form of the disease. Commonly inherited diseases related to mitochondrial abnormality are Leber hereditary optic neuropathy and myoclonic epilepsy with ragged red fibers (MERRF).
-
This question is part of the following fields:
- Genetics
- Physiology
-
-
Question 46
Incorrect
-
Which part of the neuron has the highest concentration of sodium channels per square millimetre of the cell membrane?
Your Answer: Axon terminals 20-75
Correct Answer: Nodes of Ranvier
Explanation:The nodes of Ranvier contain Na+/K+ ATPases, Na+/Ca2+ exchangers and a high density of Na+ channels. The estimated concentration of sodium channels in the node is of ∼1500/μm2.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 47
Incorrect
-
Which of the following statements is correct regarding the neuronal action potential?
Your Answer: Action potentials can have a graded response depending on the stimuli.
Correct Answer: Initial depolarisation occurs as a result of a Na + influx.
Explanation:The resting potential in most neurons has a value of approximately -70 mV. The threshold potential is generally around -55 mV. Initial depolarisation when there is Na+influx through ligand-gated Na+channels. Action potential is an all or nothing response. The size of the action potential is constant and so, the intensity of the stimulus is coded by the frequency of firing of a neuron. K+efflux is responsible for repolarisation.
-
This question is part of the following fields:
- Cell Biology
- Physiology
-
-
Question 48
Incorrect
-
Calcium is transported over the brush border in the gut, via which transporter / channel?
Your Answer: TRPV 5
Correct Answer: TRPV 6
Explanation:Transient Receptor Potential Vanilloid 6 or TRPV 6 is a calcium channel located in the cell membrane which is present in a variety of organs, including small intestine, oesophagus, stomach, colon, placenta, kidney, and uterus. In the intestine, it is located in the apical brush-border membrane of the enterocyte, regulating the entry of calcium into the cell.
-
This question is part of the following fields:
- Endocrinology
- Physiology
-
-
Question 49
Incorrect
-
The complex twisting and folding of peptide chains describes which order of protein structure?
Your Answer: Functional unit
Correct Answer: Secondary structure
Explanation:Secondary Structure refers to the coiling or folding of a polypeptide chain that gives the protein its 3-D shape. There are two types of secondary structures: the alpha (α) helix and the beta (β) pleated sheet.
-
This question is part of the following fields:
- Metabolism
- Physiology
-
-
Question 50
Incorrect
-
What is pulse pressure?
Your Answer: 1/3 systolic plus 2/3 diastolic
Correct Answer: Difference between systolic and diastolic pressure
Explanation:The pulse pressure is the difference between the measured systolic and diastolic pressures.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 51
Correct
-
Which vitamin is found in NAD and NADP?
Your Answer: Vitamin B3
Explanation:In organisms, NAD can be synthesized from simple building-blocks (de novo) from the amino acids tryptophan or aspartic acid. In an alternative fashion, more complex components of the coenzymes are taken up from food as the vitamin called niacin (vitamin B3)
-
This question is part of the following fields:
- Haematology
- Physiology
-
-
Question 52
Incorrect
-
Which of the following is true with AV nodal delay?
Your Answer: Ca++ plays a role in the delay
Correct Answer: Shortened by sympathetic stimulation
Explanation:AV nodal delay Is about 0.1s before the action potential spreads to the ventricles. It is shortened by stimulation of the sympathetic nervous system and lengthened by stimulation of the parasympathetic system.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 53
Incorrect
-
Question 54
Incorrect
-
Which of the following cells will degranulate and release histamine when binding to IgE?
Your Answer: Monocytes
Correct Answer: Basophils
Explanation:Basophils have protein receptors on their cell surface that bind IgE, an immunoglobulin involved in microparasite defence and allergy. When activated, basophils degranulate to release histamine, proteoglycans (e.g. heparin and chondroitin), and proteolytic enzymes (e.g. elastase and lysophospholipase).
-
This question is part of the following fields:
- Haematology
- Physiology
-
-
Question 55
Incorrect
-
Portal vein receives its blood from all the following except:
Your Answer: Spleen
Correct Answer: Kidney
Explanation:The portal vein receives blood from the intestines via the superior and inferior mesenteric veins, from stomach via the gastric veins and from the spleen and pancreas via splenic vein. The kidney is supplied by the renal artery and drains into the renal vein into the inferior venacava.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 56
Incorrect
-
The following are synthesized in the liver EXCEPT?
Your Answer: Antithrombin-iii
Correct Answer: Cholecystokinin
Explanation:The liver is responsible for the mainstay of protein metabolism, synthesis as well as degradation. It is also responsible for a large part of amino acid synthesis. The liver plays a role in the production of clotting factors as well as red blood cell production. Some of the proteins synthesized by the liver include coagulation factors I (fibrinogen), II (prothrombin), V, VII, VIII, IX, X, XI, XIII, as well as protein C, protein S and antithrombin. The liver is a major site of production for thrombopoietin, a glycoprotein hormone that regulates the production of platelets by the bone marrow. The liver also produces albumin, the most abundant protein in blood serum and angiotensinogen. Cholecystokinin, previously called pancreozymin, is synthesized and secreted by enteroendocrine cells in the duodenum
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 57
Incorrect
-
Which of the following does not lower ventricular rate in atrial fibrillation?
Your Answer: Digitalis
Correct Answer: Adrenaline
Explanation:Adrenaline is a sympathetic neurotransmitter which increases the heart rate. During atrial fibrillation the atria is contracting at more than 200 beats/min. Acetylcholine is a parasympathetic neurotransmitter decreasing the heart rate. Digital also depresses the conduction at the AV conduction. Vagal discharge and occulocardiac reflux decrease the heart rate and convert the tachycardia into normal sinus rhythm.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 58
Incorrect
-
Which of the following tracts are involved in the control of vital functions?
Your Answer: Rubrospinal
Correct Answer: Reticulospinal
Explanation:Reticulospinal tract pass down from the reticular formation of the mid brain, pons and medulla. It descends in the lateral white column. Both sets of fibers enter the anterior grey column and may facilitate or inhibit the gamma and alpha neurons. By this means the reticulospinal tract controls voluntary and reflex activities. It also contains the descending autonomic fiber, thus providing a pathway for the hypothalamus to control the sympathetic and parasympathetic pathways.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 59
Incorrect
-
Telomeres are best described as:
Your Answer: The protein complex involved in binding to sister chromatids.
Correct Answer: A repetitive DNA sequence at the end of a DNA molecule.
Explanation:Telomeres are non-coding DNA consisting of repetitive nucleotide sequences plus proteins that are found at the end of the linear chromosomes. They maintain the integrity of the chromosomes and prevent their shortening.
-
This question is part of the following fields:
- Genetics
- Physiology
-
-
Question 60
Correct
-
Neutrophils are key components of the innate immune system. They contain numerous primary and secondary granules involved in killing and digesting microorganisms. With regard to defensins, they are:
Your Answer: Naturally occurring cysteine-rich antibacterial and antifungal polypeptides
Explanation:Cationic antimicrobial peptides, including defensins, cathelicidins, and thrombocidins, provide important initial defences against invading microbes. These peptides bind the bacterial membrane and form pores, killing the bacterium by hypo-osmotic lysis.
-
This question is part of the following fields:
- Immunology
- Physiology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
