-
Question 1
Incorrect
-
Why is the sub-endocardial portion of the left ventricle the most common site for ischaemic damage and myocardial infarction?
Your Answer: Easily hypertrophied
Correct Answer: No blood flow occurs during systole
Explanation:The subendocardium receives the least amount of blood from the coronary arteries. 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.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 2
Incorrect
-
Concerning surface anatomy, where is the apex beat found?
Your Answer: 4th intercostal space anterior axillary line
Correct Answer: 5th intercostal space mid clavicular line
Explanation:The location of the apex beat may vary but it is mostly found in the left 5th intercostal space 6 cm from the anterior median line or in the mid clavicular line.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 3
Correct
-
Question 4
Incorrect
-
Ventricular depolarization plus ventricular repolarization is shown by the _____ interval
Your Answer: RT
Correct Answer: QT
Explanation:The QT interval represents ventricular depolarization as well as ventricular repolarization.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 5
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.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 6
Correct
-
Question 7
Incorrect
-
Question 8
Correct
-
The basic unit of contraction in myocytes is:
Your Answer: Sarcomere
Explanation:Sarcomere is the organelle where calcium is stored to be released during contraction of the muscle. It is the basic unit of contraction in striated muscle fibers. As myocytes are also striated muscles, sarcomeres also forms the basic unit of contraction. The impulses travel along the membrane and via its interaction with the dihydropyridine receptors it releases the stored calcium.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 9
Incorrect
-
The coronary arteries supply which part of the heart’s subendocardial region exclusively in diastole?
Your Answer: All chambers of the heart ( all of the above if you want )
Correct Answer: Left ventricle
Explanation:It is only during diastole that the blood flows to the subendocardial portion of the left ventricle, as the heart muscle relaxes and the coronary arteries regain their patency.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 10
Correct
-
Question 11
Correct
-
The process by which depolarization of the muscle fiber initiates contraction is called?
Your Answer: Action potential
Explanation:This process is known as an action potential. Upon generation of an action potential when depolarization reaches threshold, it spreads throughout the muscle fiber, resulting in generation of an excitation-contraction coupling leading to contraction of the muscle.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 12
Correct
-
Which of the following is true of the Natriuretic hormones?
Your Answer: They are released in response to hypervolemia
Explanation:Natriuretic hormones are vasodilators released in response to hypervolemia.
Natriuretic hormones (NH) include three groups of compounds: the natriuretic peptides NPs (ANP, BNP and CNP), the gastrointestinal peptides (guanylin and uroguanylin), and endogenous cardiac steroids. These substances induce the kidney to excrete sodium and therefore participate in the regulation of sodium and water homeostasis, blood volume, and blood pressure (BP). In addition to their peripheral functions, these hormones act as neurotransmitters or neuromodulators in the brain.
Atrial natriuretic peptide (ANP) plays a crucial role in blood pressure regulation by inducing natriuresis and diuresis in the kidney, inhibiting renin secretion, aldosterone production, and promoting vasorelaxation. Â Two paracrine factors derived from endothelial cells play important roles in modulating ANP secretion. Endothelin, a potent vasoconstrictor, stimulates ANP secretion and augments stretch induced ANP secretion. The dramatic increase in ANP release produced by cardiac ischemia appears to be mediated in part by endothelin. Nitric oxide (NO), an important vasodilator, is also produced by endothelial cells and inhibits ANP secretion.
Brain natriuretic peptide (BNP) shares ANP’s receptor but is primarily associated with antifibrotic effects in ventricular remodeling, serving as a biomarker for heart failure and myocardial infarction.
C-type natriuretic peptide (CNP) acts locally in an autocrine/paracrine manner, exerting potent cardiovascular effects, including vasorelaxation and vascular remodeling post-injury. NPs also demonstrate diverse effects beyond cardiovascular and renal systems, such as bronchodilation, anti-inflammatory actions, and metabolic effects on adipose tissue and long bones.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 13
Correct
-
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.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 14
Correct
-
The Plateau phase in myocyte action potentials does all of the following except:
Your Answer: It allows early reactivation of the myocytes
Explanation:The presence of the plateau in the action potential causes ventricular contraction to last as much as 15 times longer in cardiac muscle as in skeletal muscle. 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 (refractory) phase prevents early reactivation of the myocytes and directly determines the strength of contraction.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 15
Correct
-
According to Starling's law of the heart:
Your Answer: The extent of the preload is proportional to the end-diastolic volume
Explanation:Frank starlings law describes that an increase in the venous return or the end diastolic volume will cause an increase in the stroke volume/ preload and also cardiac output. It stems from the fact that increased venous return will increase the stretch on the ventricular muscle fibers. The sarcomere will stretch a considerable length that is needed for maximum contraction and the development of tension in the muscle fiber. The greater the venous return the greater the cardiac output. This relationship is directly proportional.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 16
Incorrect
-
Where does the SA node develop?
Your Answer: From structures on the left side of the embryo
Correct Answer: From structures on the right side of the embryo.
Explanation:The SA node develops from the right side of the embryo and the AV node from the left. This is the reason why in adults the right vagus supplies the SA node and the left vagus supplies the AV node.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 17
Correct
-
Question 18
Correct
-
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.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 19
Correct
-
Which statement about the 2nd heart sound is true?
Your Answer: It is caused by closure of the aortic and pulmonary valves.
Explanation:The second heart sound is produced due to closure of the aortic and pulmonary valves. It is a high pitched dub sound.
Normally the aortic closure sound (A2) occurs prior to the pulmonic closure sound (P2), and the interval between the two (splitting) widens on inspiration and narrows on expiration. With quiet respiration, A2 will normally precede P2 by 0.02 to 0.08 second (mean, 0.03 to 0.04 sec) with inspiration. In younger subjects inspiratory splitting averages 0.04 to 0.05 second during quiet respiration. With expiration, A2 and P2 may be superimposed and are rarely split as much as 0.04 second. If the second sound is split by greater than 0.04 second on expiration, it is usually abnormal. Therefore, the presence of audible splitting during expiration (i.e., the ability to hear two distinct sounds during expiration) is of greater significance at the bedside in identifying underlying cardiac pathology than is the absolute inspiratory increase in the A2–P2 interval.
The respiratory variation of the second heart sound can be categorized as follows: (1) normal (physiologic) splitting; (2) persistent (audible expiratory) splitting, with normal respiratory variation; (3) persistent splitting without respiratory variation (fixed splitting); and (4) reversed (paradoxical) splitting.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 20
Incorrect
-
How does pregnancy affect the cardiac output of a patient?
Your Answer: Increased cardiac output due to increase in stroke volume, whilst the heart rate remains unchanged
Correct Answer: Increased cardiac output due to increase in heart rate and stroke volume
Explanation:Cardiac Output increases to a similar degree as the blood volume. During the first trimester cardiac output is 30-40% higher than in the non-pregnant state. Steady rises are shown on Doppler echocardiography, from an average of 6.7 litres/minute at 8-11 weeks to about 8.7 litres/minute flow at 36-39 weeks; they are due, primarily, to an increase in stroke volume (35%) and, to a lesser extent, to a more rapid heart rate (15%). There is a steady reduction in systemic vascular resistance (SVR) which contributes towards the hyperdynamic circulation observed in pregnancy
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 21
Incorrect
-
Transport of Ca2+ into the reticulum to initiate cardiac muscle relaxation in via:
Your Answer: Dihydropyridine receptors
Correct Answer: Serca (sarcoplasmic or endoplasmic reticulum Ca2+ ATPase)
Explanation:Phosphorylation of phospholamban, which increases calcium ATPase activity and sequestration of calcium in the sarcoplasmic reticulum. An increased rate of relaxation is explained because cAMP also activates the protein phospholamban, situated on the membrane of the SR, that controls the rate of uptake of calcium into the SR. The latter effect explains enhanced relaxation (lusitropic effect).
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 22
Correct
-
The interventricular septum is supplied anteriorly by the?
Your 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
- Medicine
-
-
Question 23
Correct
-
Regarding blood supply to the heart;
Your Answer: Coronary arteries fill as the heart relaxes
Explanation:The heart muscles acts like the skeletal muscle in the fact that it also compress the vessels during contraction. As the pressure in the ventricle is slightly greater than in the aorta the coronary vessels collapse during systole. Blood flows through them during the diastole phase of contraction.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 24
Incorrect
-
Pacemaker cells in the SA node and the AV node are connected by?
Your Answer: P cells
Correct Answer: Gap junctions
Explanation:Gap junctions allows for rapid propagation of the action potential from one cell to the other. The cells of the heart are connected by gap junctions.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 25
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
- Medicine
-
-
Question 26
Incorrect
-
Closure of the tricuspid valve is marked by which of the following features of the jugular venous waveform?
Your Answer: x descent
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
- Medicine
-
-
Question 27
Correct
-
Factors influencing cardiac output include which of the following?
Your Answer: All of the above
Explanation:There is a correlation between resting CO and body surface area. The output per min per square meter of body surface (the cardiac index) averages 3.2l.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 28
Correct
-
Which of the following does not contribute to increased stroke volume during exercise?
Your Answer: Increased length of filling time during diastole
Explanation:Prolonged aerobic exercise training may also increase stroke volume, which frequently results in a lower (resting) heart rate. Reduced heart rate prolongs ventricular diastole (filling), increasing end-diastolic volume, and ultimately allowing more blood to be ejected.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 29
Incorrect
-
Where would one find pericytes around endothelial cells?
Your Answer: Pre-capillary venules
Correct Answer: Post-capillary venules
Explanation:Pericytes release a wide variety of vasoactive agents which regulate the flow through the junction between endothelial cells.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 30
Incorrect
-
Which vaso metabolite decreases coronary blood flow?
Your Answer: Adenosine
Correct 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.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 31
Correct
-
In ventricular fibrillation (VF), the first defibrillation attempt (with a biphasic defibrillator) should be made at:
Your Answer: 200 J
Explanation:Defibrillation is a common treatment for life-threatening cardiac dysrhythmias and ventricular fibrillation. If the patient is in Ventricular tachycardia (VT) or ventricular fibrillation (VF) on the monitor, immediately apply the pads and shock the patient with 120-200 Joules on a biphasic defibrillator or 360 Joules on a monophasic defibrillator.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 32
Correct
-
Which of the following is the most common causative organism in infective endocarditis?
Your Answer: Streptococcus viridans
Explanation:Viridans Alpha-haemolytic streptococci, that are present in the mouth are the most frequently isolated microorganisms when the infection is acquired in a community setting. In contrast, Staphylococcus blood stream infections are frequently acquired in a health care setting where they can enter the blood stream through procedures that cause break in the integrity of skin like surgery, catheterisation or during access of long term indwelling catheters or secondary to intravenous injection of recreational drugs.Prosthetic valve endocarditis is commonly caused by Staphylococcus epidermidis as it is capable of growing as a biofilm on plastic surfaces
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 33
Incorrect
-
Myocardium requires more oxygen to expel blood in:
Your Answer: An incompetent tricuspid 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
- Medicine
-
-
Question 34
Correct
-
Which of the following factors serve to decrease cardiac output?
Your Answer: Standing from a lying position
Explanation:Sleep has no effect on the cardiac output. Anxiety, excitement, increased body temperature and pregnancy will increase the cardiac output. Standing from a lying position will decrease the cardiac output transiently.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 35
Incorrect
-
Arterioles stemming from the coronary artery can also empty into the heart directly via the:
Your Answer: All arterioles empty into the coronary sinus or anterior cardiac vein
Correct Answer: Arteriosinusoidal vessels
Explanation: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. They include arteriosinusoidal vessels, which connect the arterioles to the heart chambers. The thebesian veins drain the capillaries into the chambers and the arterioluminal vessels drain small arteries directly into the chambers.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 36
Correct
-
Question 37
Incorrect
-
Select the correct statement regarding the 4th heart sound, it?
Your Answer: Occurs after the second heart sound.
Correct Answer: Can be heard in atrial systole.
Explanation:The fourth heart sound is not normally audible in a normal adult. It occurs as a consequence of ventricular hypertrophy. It is caused by filling of the ventricle by atrial systole.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 38
Correct
-
What is the function of the BK channel on the vascular smooth muscle membrane?
Your Answer: Massive K+ efflux, increasing membrane potential, and shutting off the voltage gated Ca2+ channel
Explanation:BK channels, also known as large-conductance calcium-activated potassium channels, play a critical role in regulating vascular smooth muscle tone. When BK channels open, they allow a large efflux of potassium ions (K+) out of the cell. This efflux of K+ causes the membrane potential to become more negative (hyperpolarization), which in turn leads to the closure of voltage-gated calcium channels. The closure of these calcium channels reduces the influx of calcium ions (Ca2+) into the smooth muscle cells, resulting in decreased intracellular calcium levels and subsequent relaxation of the smooth muscle.
Thus, BK channels promote smooth muscle relaxation by hyperpolarizing the membrane and reducing the activity of voltage-gated Ca2+ channels.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 39
Incorrect
-
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: Calcium ATPase
Correct 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
- Medicine
-
-
Question 40
Correct
-
Question 41
Incorrect
-
All of the following are consistent with the indicator dilution method except---
Your Answer: The cardiac output is equal to the amount of indicator injected divided by its average concentration in arterial blood after a single circulation though the heart
Correct Answer: In thermodilution, the indicator used is warm saline
Explanation:In thermodilution, the indicator used is cold saline.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 42
Incorrect
-
Tunica intima is made up of?
Your Answer: Smooth muscle cells
Correct Answer: Endothelial cells
Explanation:Tunica intima is a single cell thick lining of endothelial cells that lines the inside of the blood vessels. It is the inner most layer of the blood vessel.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 43
Correct
-
When the heart rate is increased (to pathological levels) which of the following is correct when comparing the duration of diastole to systole?
Your Answer: It is shortened to a greater degree
Explanation:The duration of systole is more fixed than the duration of diastole. When the heart rate increases the timing of the systole remains more or less the same however diastole decreases.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 44
Correct
-
The hyperpolarization phase of pacemaker cells is dominated by ____ current.
Your Answer: K+
Explanation:The hyperpolarization phase is a continuation of the repolarization phase but the membrane potential dips below the resting membrane potential. This results due to the fact that the K+ channels take a longer time to close than the Na+ channels. Hence efflux of the K+ will result in hyperpolarization.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 45
Correct
-
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.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 46
Incorrect
-
The right border of the heart corresponds to which line on the surface of the chest?
Your Answer: Line drawn from the 3rd left costal cartilage to the 6th left costal cartilage
Correct Answer: Line drawn from the 3rd right costal cartilage to the 6th right costal cartilage
Explanation:The right border corresponds to a line drawn from the 3rd right costal cartilage to the 6th right costal cartilage; this border is slightly convex to the right.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 47
Incorrect
-
Which of the following suggests the presence of mitral regurgitation as well as mitral stenosis?
Your Answer: Localised tapping apex beat
Correct Answer: Displaced apex beat
Explanation:Mitral stenosis on its own does not lead to left ventricular dilatation and hence a displaced apex beat. Thus a displaced apex beat is suggestive of mixed mitral disease. The other options occur in mitral stenosis.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 48
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.
-
This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 49
Correct
-
Question 50
Correct
-
Most of the venous blood returns to the heart through the:
Your 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
- Medicine
-
SESSION STATS - PERFORMANCE PER SPECIALTY
