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  • Question 1 - Absolute refractory period in a cardiac action potential graph occurs during. ...

    Correct

    • Absolute refractory period in a cardiac action potential graph occurs during.

      Your Answer: All of the above

      Explanation:

      Absolute refractory period (ARP): the cell is completely unexcitable to a new stimulus and occurs from phase 0 – 2 i.e. depolarisation, early repolarisation and plateau phase.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.8
      Seconds

  • Question 2 - Which of the following isoforms of Nitric oxide synthase (NOS) is found in...

    Correct

    • Which of the following isoforms of Nitric oxide synthase (NOS) is found in endothelial cells?

      Your Answer: Nos 3

      Explanation:

      There are only 3 isoforms:NOS 1: found in nervous systemNOS 2: in macrophages and other immune cellsNOS 3: In endothelial cells

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      3.5
      Seconds

  • Question 3 - The coronary arteries fill during? ...

    Correct

    • The coronary arteries fill during?

      Your Answer: Diastole

      Explanation:

      During systole the coronary arteries collapse as a result of the pressure due to contraction that is exerted on them. During diastole the heart muscle relaxes and the pressure on the coronary vessels is relieved allowing blood to flow through them to the subendocardium.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      6.9
      Seconds

  • Question 4 - Closure of the tricuspid valve is marked by which of the following features...

    Incorrect

    • Closure of the tricuspid valve is marked by which of the following features of the jugular venous waveform?

      Your Answer: a wave

      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
      3.2
      Seconds

  • Question 5 - Which of the following suggests the presence of mitral regurgitation as well as...

    Incorrect

    • Which of the following suggests the presence of mitral regurgitation as well as mitral stenosis?

      Your Answer: Raised JVP

      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
      3.3
      Seconds

  • Question 6 - The following are examples of the functions of the vascular endothelium except: ...

    Incorrect

    • The following are examples of the functions of the vascular endothelium except:

      Your Answer: Vasomotor control

      Correct Answer: Tumour suppression

      Explanation:

      Vascular endothelium has many important functions including regulation of vascular tone, molecular exchange between blood and tissue compartments, hemostasis and signaling for the immune regulation and inflammation. Depending on specific tissue needs and local stresses, endothelial cells are capable of evoking either antithrombotic or prothrombotic events. Tumor suppression is related to genes, or anti-oncogenes, that regulate a cell during cell division and replication.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      3.3
      Seconds

  • Question 7 - Why is the sub-endocardial portion of the left ventricle the most common site...

    Correct

    • Why is the sub-endocardial portion of the left ventricle the most common site for ischaemic damage and myocardial infarction?

      Your 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
      4.4
      Seconds

  • Question 8 - Which vagus nerve mainly supplies the AV node? ...

    Correct

    • Which vagus nerve mainly supplies the AV node?

      Your Answer: Left vagus

      Explanation:

      As the AV node develops from the left side of the embryo It is supplied by the left vagus nerve.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.9
      Seconds

  • Question 9 - During which phase of the cardiac cycle does most of the ventricular filling...

    Incorrect

    • During which phase of the cardiac cycle does most of the ventricular filling occur?

      Your Answer: Ventricular ejection

      Correct Answer: Ventricular diastole

      Explanation:

      During the phase of ventricular diastole when the heart muscle relaxes and all the valves are open, blood flows easily into the heart. This is the phase of rapid ventricular filling. During isovolumetric contraction and relaxation the volume of blood in the heart does not change. During ventricular ejection blood enters into the aorta and pulmonary vessels.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      12
      Seconds

  • Question 10 - Impulse conduction through the AV node is slow and depends on the action...

    Correct

    • Impulse conduction through the AV node is slow and depends on the action potential produced by which of the following.

      Your Answer: Calcium flux

      Explanation:

      The action potentials in the SA and AV nodes are largely due to Ca2+, with no contribution by Na+ influx.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.7
      Seconds

  • Question 11 - Endothelial cells are attached to adjacent cells by adherent junctions via: ...

    Incorrect

    • Endothelial cells are attached to adjacent cells by adherent junctions via:

      Your Answer: Selectins

      Correct Answer: Cadherins

      Explanation:

      Cadherins are calcium dependant molecules that mediate cell to cell adhesions in epithelial and endothelial cells among others.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.9
      Seconds

  • Question 12 - Generalized vasoconstrictors include: ...

    Incorrect

    • Generalized vasoconstrictors include:

      Your Answer: Epinephrine, kinin, endothelin

      Correct Answer: Norepinephrine, endothelin, angiotensin ii

      Explanation:

      Vasopressin, angiotensin II, adrenaline and endothelin are generalized vasoconstrictors.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      6.1
      Seconds

  • Question 13 - Troponin I is inhibited by calcium binding to: ...

    Incorrect

    • Troponin I is inhibited by calcium binding to:

      Your Answer: Tropomyosin

      Correct Answer: Troponin c

      Explanation:

      At rest troponin I is bound to actin and tropomyosin and covers the site where the myosin head interacts with actin. When calcium enters into the muscle, it binds with troponin C and cause a structural change in troponin I which moves out of the myosin binding site and causes the cross bridges between the actin and myosin filaments to occur.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      5.5
      Seconds

  • Question 14 - Where is the carotid sinus located? ...

    Correct

    • Where is the carotid sinus located?

      Your 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
      13.4
      Seconds

  • Question 15 - The positive inotropic effect of digoxin is due to? ...

    Correct

    • The positive inotropic effect of digoxin is due to?

      Your Answer: Inhibition of the sodium potassium ATPase in the myocardium

      Explanation:

      Digitalis compounds are potent inhibitors of cellular Na+/K+-ATPase. This ion transport system moves sodium ions out of the cell and brings potassium ions into the cell. By inhibiting the Na+/K+-ATPase, cardiac glycosides cause the intracellular sodium concentration to increase. This then leads to an accumulation of intracellular calcium via the Na+/Ca++ exchange system. In the heart, increased intracellular calcium causes more calcium to be released by the sarcoplasmic reticulum, thereby making more calcium available to bind to troponin-C, which increases contractility (inotropy).

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      22.7
      Seconds

  • Question 16 - Concerning surface anatomy, where is the base of the heart ...

    Incorrect

    • Concerning surface anatomy, where is the base of the heart

      Your Answer: 5th intercostal space mid clavicular line

      Correct Answer: 2nd left costal to 3rd right costal cartilage

      Explanation:

      The base of the heart, also known as the superior border of the heart corresponds to a line connecting the inferior border of the 2nd left costal cartilage to the superior border of the 3rd right costal cartilage.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      25
      Seconds

  • Question 17 - The Plateau phase in myocyte action potentials does all of the following except:...

    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
      8.2
      Seconds

  • Question 18 - The right border of the heart corresponds to which line on the surface...

    Incorrect

    • The right border of the heart corresponds to which line on the surface of the chest?

      Your Answer: Line drawn from the 4th right costal cartilage to the 5th left intercostal space

      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
      8.3
      Seconds

  • Question 19 - Cholinergic vagal supply to the SA and AV nodes results in slowing of...

    Incorrect

    • Cholinergic vagal supply to the SA and AV nodes results in slowing of the heart rate via:

      Your Answer: B1 receptors

      Correct Answer: M2 muscarinic receptors

      Explanation:

      M2 muscarinic receptors are the receptors for the parasympathetic system to the SA and the AV node.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      8.5
      Seconds

  • Question 20 - Although variable, branches of which artery most often supply the SA and AV...

    Incorrect

    • Although variable, branches of which artery most often supply the SA and AV nodes?

      Your Answer: Left coronary artery

      Correct Answer: Right coronary artery

      Explanation:

      The RCA (right coronary artery) supplies the SA and the AV nodes along with the postero-basal wall of the left ventricle, posterior one third of the inferior vena cava, right ventricle and the posteromedial papillary muscle in the left ventricle.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      8.4
      Seconds

  • Question 21 - When looking at the JVP what does the c wave signify: ...

    Incorrect

    • When looking at the JVP what does the c wave signify:

      Your Answer: Complete heart block

      Correct Answer: Isovolumetric ventricular contraction

      Explanation:

      The C wave signifies a rise in the atrial pressure during isovolumetric contraction due to the tricuspid valve bulging into the atria.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      3.2
      Seconds

  • Question 22 - Where are the baroreceptors of the great arteries located? ...

    Incorrect

    • Where are the baroreceptors of the great arteries located?

      Your Answer: In the endothelium

      Correct Answer: In the adventitia

      Explanation:

      Arterial baroreceptors are located in the aortic arch and carotid sinuses, and are formed by small nerve endings present in the adventitia of these vessels.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      3.4
      Seconds

  • Question 23 - The following contributes to the rate of depolarization? ...

    Incorrect

    • The following contributes to the rate of depolarization?

      Your Answer: Hypoxia

      Correct 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
      112.8
      Seconds

  • Question 24 - Excitation-contraction coupling in cardiac muscle involves all of the following except: ...

    Correct

    • Excitation-contraction coupling in cardiac muscle involves all of the following except:

      Your Answer: Binding of Ca2+ to calmodulin

      Explanation:

      In the excitation contraction coupling model, an action potential is transmitted to the fibrils of a fiber through the T tubule system. It triggers the release of Ca 2+ from the terminal cisterns. Depolarization of the T tubules activates the sarcoplasmic reticulum through the dihydropyridine receptors. These are voltage gates calcium channels. Calcium binds to calmodulin during contraction of the smooth muscle and not the cardiac muscles.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      9.2
      Seconds

  • Question 25 - Which of the following structures of the cardiac conduction system is located in...

    Incorrect

    • Which of the following structures of the cardiac conduction system is located in the right posterior portion of the interatrial septum?

      Your Answer: Internodal atrial pathways

      Correct Answer: AV node

      Explanation:

      AV node is located at the right posterior portion of the interatrial septum.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      9.2
      Seconds

  • Question 26 - In cardiac muscle, which of the following is directly responsible for the release...

    Incorrect

    • In cardiac muscle, which of the following is directly responsible for the release of Ca2+ stored in the sarcoplasmic reticulum (calcium-induced calcium release)?

      Your Answer: Dihydropyridine receptors (DHPR)

      Correct Answer: Ryanodine receptor (RyR)

      Explanation:

      Ryanodine receptor (RyR) is a ligand-gated Ca2+ channel with Ca2+ as its natural ligand. In skeletal muscle, Ca2+ entry from ECF by this route is not required for Ca2+ release. Instead, the DHPR that serves as the voltage sensor unlocks release of Ca2+ from the nearby SR via physical interaction with the RyR. The release is amplified through ca-induced ca release. However, in cardiac muscle, it is the influx of extracellular Ca2+ through the voltage-sensitive DHPR in the T system that triggers ca-induced ca release trough the RyR at the SR.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      3
      Seconds

  • Question 27 - Which statement about the 2nd heart sound is true? ...

    Incorrect

    • Which statement about the 2nd heart sound is true?

      Your Answer: It is softer in pulmonary hypertension.

      Correct 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
      3.6
      Seconds

  • Question 28 - The postextrasystolic potentiation of myocardial contractility is due to: ...

    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
      3.4
      Seconds

  • Question 29 - Arterioles stemming from the coronary artery can also empty into the heart directly...

    Incorrect

    • Arterioles stemming from the coronary artery can also empty into the heart directly via the:

      Your Answer: AV fistulas

      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
      10.1
      Seconds

  • Question 30 - What is the effect of catecholamines (i.e. increased heart rate) on the pressure...

    Incorrect

    • What is the effect of catecholamines (i.e. increased heart rate) on the pressure volume loop?

      Your Answer:

      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
      0
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (26/29) 90%
Medicine (26/29) 90%
Passmed
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