-
Question 1
Incorrect
-
The following determines the strength of contraction
Your Answer: None of the above
Correct Answer: Plateau phase
Explanation:The plateau phase which follows is unique to myocytes and results from a small, but sustained inward calcium current through L-type calcium channels lasting 200-400 ms. This calcium influx is caused by a combined increase in permeability of the cell and especially the sarcolemmal membranes to calcium. This plateau (or refractory) phase in myocyte action potential prevents early reactivation of the myocytes and directly determines the strength of contraction
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 2
Incorrect
-
The process of DNA amplification and quantification is called:
Your Answer:
Correct Answer: PCR
Explanation:PCR/polymerase chain reaction is a procedure carried out in a test tube that can be used on the smallest amount of DNA to amplify it, allowing for millions of copies of specific nucleotides to be made.
-
This question is part of the following fields:
- Genetics
- Physiology
-
-
Question 3
Incorrect
-
Closure of the tricuspid valve is marked by which of the following features of the jugular venous waveform?
Your Answer:
Correct Answer: c wave
Explanation:The jugular venous pressure (JVP) classically has three upward deflections and two downward deflections. The upward deflections are the a (atrial contraction), c (ventricular contraction and resulting bulging of tricuspid into the right atrium during isovolumetric systole) and v = venous filling. The downward deflections of the wave are the x (the atrium relaxes and the tricuspid valve moves downward) and the y descent (filling of ventricle after tricuspid opening).
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 4
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:
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 5
Incorrect
-
A biopsy taken from the respiratory passage of a 37 year old male, chronic smoker will mostly likely show which cellular adaptation?
Your Answer:
Correct Answer: Stratified squamous metaplasia
Explanation:Metaplasia is a change in the cell type caused in part due to an extrinsic stress on the organ. It involves a change in the surface epithelium from one cell type to the another, most commonly squamous to columnar. This is a reversible process, and removal of the stress should theoretically reverse the surface epithelium back to normal morphology. Respiratory tract metaplasia is a classic example, in which the normal pseudostratified columnar epithelium is replaced by stratified squamous epithelium to better cope with the stress. Under continuous stress metaplasia can progress to dysplasia which is a disordered growth of cells eventually leading to the development of carcinoma.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 6
Incorrect
-
What type of pump is the Na+/K+ATPase pump?
Your Answer:
Correct Answer: An antiporter
Explanation:In order for primary active transport to pump ions against their electrochemical gradient, chemical energy is used in the form of ATP. This is facilitated by the Na+/K+-ATPase antiporter pump, which uses metabolic energy to move 3 Na+ions out of the cell for every 2 K+ions that come in, against their respective electrochemical gradients. As a result, the cell the maintains a high intracellular concentration of K+ions and a low concentration of Na+ions.
-
This question is part of the following fields:
- Cell Biology
- Physiology
-
-
Question 7
Incorrect
-
What is the structure of nucleosomes?
Your Answer:
Correct Answer: Strands of double strand DNA + histones
Explanation:DNA is packed and condensed by binding to histone proteins. The double stranded DNA forms a complex with histone proteins which is called a nucleosome. There are 8 histone proteins contained in one core of nucleosome.
-
This question is part of the following fields:
- Genetics
- Physiology
-
-
Question 8
Incorrect
-
Which of the following features of cell damage tends to be reversible:
Your Answer:
Correct Answer: Swelling of endoplasmic reticulum and some mitochondria
Explanation:Features of cell damage that tend to be reversible include: swelling of endoplasmic reticulum and some mitochondrialoss of ribosomescell stress response Features of cell damage that tend to be irreversible include: loss of nucleolus, no ribosomes, swelling of all mitochondria, nuclear condensation, membrane blebs and holes, lysosome rupture, fragmentation of all inner membranes, nuclear breakup
-
This question is part of the following fields:
- Inflammatory Responses
- Pathology
-
-
Question 9
Incorrect
-
Question 10
Incorrect
-
The following are Gram-negative cocci:
Your Answer:
Correct Answer: Neisseria
Explanation:Gram-negative cocci include the four types that cause a sexually transmitted disease (Neisseria gonorrhoeae), a meningitis (Neisseria meningitidis), and respiratory symptoms (Moraxella catarrhalis, Haemophilus influenzae).
-
This question is part of the following fields:
- Infectious Diseases
- Physiology
-
-
Question 11
Incorrect
-
Stimulation of the carotid sinus results in:
Your Answer:
Correct Answer: Drop in blood pressure
Explanation:Stimulation of the carotid sinus will result in an increase in the baroreceptor discharge. This will travel via the afferent nerves to the medulla. Signals will pass through the vagus nerve to decrease the sympathetic outflow to the heart and the blood vessels. This inhibition will result in vasodilation of the blood vessels, venodilation and bradycardia hence decreasing the total peripheral resistance and lowering the blood pressure.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 12
Incorrect
-
Which hormone secreting cell of the human anterior pituitary gland secretes growth hormone?
Your Answer:
Correct Answer: Somatotroph
Explanation:Somatotroph cells are responsible for the production of growth hormone. Somatotrophs occupy nearly 40% of the total surface area of the anterior pituitary, and they are acidophilic in nature.
-
This question is part of the following fields:
- Endocrinology
- Physiology
-
-
Question 13
Incorrect
-
Elevation of the eyeball is primarily produced by which of the following muscles:
Your Answer:
Correct Answer: Superior rectus and inferior oblique
Explanation:Elevation of the eyeball is produced by the superior rectus and the inferior oblique muscles.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 14
Incorrect
-
Cranial nerves VI, VII, VIII enter/exit the base of the brain at the:
Your Answer:
Correct Answer: Ponto-medullary junction
Explanation:Cranial nerves III, IV and V exit from the pons, VI, VII, VIII exit from the pontomedullary junction and cranial nerve IX, X, XI, XII exit from the medulla.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 15
Incorrect
-
The interventricular septum is supplied anteriorly by the?
Your Answer:
Correct Answer: Left anterior descending artery
Explanation:The anterior interventricular artery or left anterior descending artery supplies the anterior 2/3rds of the interventricular septum.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 16
Incorrect
-
Question 17
Incorrect
-
With regard to the cell cycle. In which part of the cycle does DNA replication occur?
Your Answer:
Correct Answer: Interphase
Explanation:DNA replication occurs during S phase but that isn’t one of the options. Remember Interphase comprises G1,S and G2 phases!
-
This question is part of the following fields:
- Cell Biology
- Physiology
-
-
Question 18
Incorrect
-
Which of the following is a method for measurement of cardiac output?
Your Answer:
Correct Answer: Indicator dilution method
Explanation:There are two methods of calculating the cardiac output in humans other than doppler with echocardiography: The direct Fick’s method and the indicator dilution method. In the indicator dilution technique, a known amount of a substance such as a dye or, more commonly, a radioactive isotope is injected into an arm vein and the concentration of the indicator in serial samples of arterial blood is determined. The output of the heart is equal to the amount of indicator injected divided by its average concentration in arterial blood after a single circulation through the heart.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 19
Incorrect
-
In the gastric mucosa, which of the following cells is known to secrete gastric lipase?
Your Answer:
Correct Answer: Chief cell
Explanation:Chief cells produce pepsinogen and gastric lipase. Parietal cells produce stomach acid and intrinsic factor.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 20
Incorrect
-
An obstruction in a pulmonary artery causes impaired perfusion to an area in the lung. The gas values in the unperfused alveoli at sea level will be:
Your Answer:
Correct Answer: PO2 = 149 C02 =0
Explanation:Partial pressure of oxygen at sea level is approximately 160 mmHg. Partial pressure of oxygen in alveoli is around 150 mmHg and in an arteriole is around 80-100 mmHg. Partial pressure of carbon dioxide is around 35 mmHg in alveolar air and around 40 mmHg in the arteriole.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 21
Incorrect
-
Regarding transportation of iron in the body, the process in which iron is transported from the enterocyte into the blood occurs using which transporter protein:
Your Answer:
Correct Answer: Ferroportin
Explanation:Divalent metal transporter 1 (DMT1) transport several divalent metals including iron across the enterocyte’s cell membrane into the cell. The cell can then release it into the body via the only known iron exporter in mammals, ferroportin.
-
This question is part of the following fields:
- Haematology
- Physiology
-
-
Question 22
Incorrect
-
A 85 year old male with a history of Alzheimer's dementia was brought into Casualty by family members, who stated that he had episodes of aggression. Which of the following drugs is most suitable as the pharmacological management for this presentation?
Your Answer:
Correct Answer: Risperidone
Explanation:Regarding the pharmacological management, Risperidone is the most suitable drug from the given answers as it is recommended for the treatment of aggression associated with moderate to severe Alzheimer’s disease. Quetiapine and Benzodiazepine are not recommended.
-
This question is part of the following fields:
- Geriatrics
- Physiology
-
-
Question 23
Incorrect
-
Regarding taste threshold and intensity discrimination:
Your Answer:
Correct Answer: 30% change in concentration of substance tasted is necessary before an intensity difference can be detected
Explanation:The ability of humans to differentiate differences in intensity of taste is poor. A 30% change in the concentration of the substance being tasted is required before an intensity difference is perceived.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 24
Incorrect
-
Eosinophils provide immunity against
Your Answer:
Correct Answer: Multi cellular parasites
Explanation:Eosinophils, are a variety of white blood cells and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates.
-
This question is part of the following fields:
- Immunology
- Physiology
-
-
Question 25
Incorrect
-
The following statements concern the sensory innervation of the nasal passage:
Your Answer:
Correct Answer: the infraorbital branch of the maxillary nerve supplies the vestibule
Explanation:The walls of the anterior nasal passage are supplied by the anterior ethmoidal branch of the nasociliary nerve, and the floor is innervated by the superior dental nerve (not the sphenopalatine nerves). The walls and floor of the posterior nasal passage are innervated by the long and short sphenopalatine nerves and the great palatine nerve (not the superior dental nerves and the nasociliary nerve). The vestibule is innervated by small branches of the infraorbital branch of the maxillary nerve. The nasopharynx is innervated by the sensory branches of the trigeminal nerve (not the great palatine nerve).
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 26
Incorrect
-
Oxygen enters blood from the alveoli by:
Your Answer:
Correct Answer: Passive diffusion
Explanation:Oxygen enters blood from the alveoli by simple diffusion along a concentration gradient. Concentration of oxygen and the partial pressure of oxygen in the alveoli are higher than the partial pressure of oxygen in the blood. So, oxygen moves from alveoli into blood via simple diffusion according to the concentration gradient.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 27
Incorrect
-
A 34-year-old woman was diagnosed with multiple sclerosis two years ago. Her symptoms have been steadily deteriorating, with no intervals of remission in sight. Which of the following aspects of nerve conduction is disrupted by multiple sclerosis?
Your Answer:
Correct Answer: Saltatory conduction
Explanation:Local currents propagate action potentials down the axons of neurons. This local current flow following depolarisation results in the depolarisation of the neighbouring axonal membrane, and when this region approaches the threshold, more action potentials are generated and so forth. Due to the refractory period, portions of the membrane that have recently depolarized will not depolarize again, resulting in the action potential only being able to go in one direction. The square root of axonal diameter determines the velocity of the action potential; the axons with the biggest diameter have the quickest conduction velocities. When a neuron is myelinated, the speed of the action potential rises as well. The myelin sheath is an insulating coating that surrounds certain neural axons. By increasing membrane resistance and decreasing membrane capacitance, the myelin sheath improves conduction. This enables faster electrical signal transmission via a neuron, making them more energy-efficient than non-myelinated neuronal axons. Electrical impulses are quickly transmitted from one node to the next, causing depolarization of the membrane above the threshold and triggering another action potential, which is then transmitted to the next node. An action potential is rapidly conducted down a neuron in this manner. Saltatory conduction is the term for this. Multiple sclerosis is an example of a clinical disorder in which the myelin sheath is affected. It is an immune-mediated disorder in which certain nerve cells in the brain and spinal cord become demyelinated. The ability of some areas of the nervous system to properly transmit action potentials is disrupted by demyelination, resulting in a variety of neurological symptoms and indications.
-
This question is part of the following fields:
- Cell Biology
- Physiology
-
-
Question 28
Incorrect
-
During an operation to repair an aortic coarctation in a neonate, a surgeon accidentally cuts the first aortic intercostal arteries as he mobilised the descending aorta. Which one of the following structure might be deprived of its primary source of blood supply following this injury?
Your Answer:
Correct Answer: Right bronchus
Explanation:The right bronchus is supplied by one right bronchial artery that may branch from one of the left bronchial arteries or from the right 3rd posterior intercostal artery (this is the first intercostal artery that arises from the aorta). Damage to this artery might stop blood supply to the main bronchus. Intercostal arteries that go to the first and the second interspaces originate from the highest intercostal artery such that blood supply to either of these spaces would not be interfered with.The left bronchus receives blood from 2 left bronchial arteries which are direct branches from the descending aorta. Fibrous pericardium is the sac that contains the heart. Its blood supply is not a major concern. Visceral pericardium receives its blood supply from the coronary vessels.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 29
Incorrect
-
Which of the following is first to rise following myocardial infarction?
Your Answer:
Correct Answer: Myoglobin
Explanation:Myoglobin, is a sensitive indicator of muscle injury and is first to rise following MI within two hours but is nonspecific.Troponin and CK-MB both begin to rise approximately three hours after MI. The cardiac troponins T and I which are released within 4–6 hours of an attack of MI and remain elevated for up to 2 weeks, have nearly complete tissue specificity and are now the preferred markers for assessing myocardial damage.Lactate dehydrogenase (LDH) begins to rise approximately 12 hours after MI.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 30
Incorrect
-
Normal parents have a child with a recessive condition, Tay Sachs. The chance of them having a normal child is?
Your Answer:
Correct Answer: 75%
Explanation:The chance for normal parents having a child with a recessive disease is 1:4 or 25%. As both the parents are heterozygous for this condition. They have a 3:4 chance of having a normal child or 75%.
-
This question is part of the following fields:
- Genetics
- Physiology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
