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  • Question 1 - 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: M1 muscarinic 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
      12.8
      Seconds

  • Question 2 - Currents caused by opening of which of the following channels contribute to the...

    Correct

    • Currents caused by opening of which of the following channels contribute to the repolarization phase of the action potential of the ventricular muscle fibers?

      Your Answer: Potassium channels

      Explanation:

      Depolarization occurs due to opening of the voltage gated sodium channels. Repolarization occurs due to opening of the voltage gates potassium channels causing an out flux of potassium ions, decreasing the membrane potential towards resting potential.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      24.3
      Seconds

  • Question 3 - Which of the following causes the closure of the ductus arteriosus during birth?...

    Correct

    • Which of the following causes the closure of the ductus arteriosus during birth?

      Your Answer: Reduced levels of prostaglandins

      Explanation:

      Ductus arteriosus is kept open by the prostaglandin E2 which is a vasodilator. At birth the high levels of cyclooxygenase blocks the production of prostaglandins which results in the closure of the ductus arteriosus.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      36.1
      Seconds

  • Question 4 - Following an action potential, cytosolic Ca2+ is increased. The binding of free Ca2+...

    Incorrect

    • Following an action potential, cytosolic Ca2+ is increased. The binding of free Ca2+ to troponin C results in all of the following except:

      Your Answer: Inhibition of troponin i

      Correct Answer: Weakening of the troponin i interaction with actin

      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
      50
      Seconds

  • Question 5 - Regarding cardiac contractility, catecholamines exert their inotropic effect via: ...

    Correct

    • Regarding cardiac contractility, catecholamines exert their inotropic effect via:

      Your Answer: Î’1-adrenergic receptors and gs

      Explanation:

      Catecholamines exert their inotropic effect on the heart via the B1 adrenergic receptors and Gs, stimulating adenyl cyclase and increasing the production of cAMP.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      14.5
      Seconds

  • Question 6 - Calcium needed for cardiac muscle contraction is made available during which phase of...

    Correct

    • Calcium needed for cardiac muscle contraction is made available during which phase of the action potential?

      Your Answer: 2

      Explanation:

      It is made available during the plateau phase of the action potential i.e. phase 2. During the plateau phase of the action potential, Calcium from the extracellular fluid enters through the L type of calcium channels. This entry triggers the release of more calcium from the sarcoplasmic reticulum via the ryanodine receptors.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      13.4
      Seconds

  • Question 7 - Which of the following makes up the thick filaments in muscle fibers? ...

    Correct

    • Which of the following makes up the thick filaments in muscle fibers?

      Your Answer: Myosin

      Explanation:

      The thick filaments are made up of myosin and the thin filaments are made up of actin. The thick filaments are twice the size of the thin filaments and are aligned to form the A band. The thin filaments extending out from the A band form the less dense I bands.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      6.4
      Seconds

  • Question 8 - Depolarization of the T tubule membrane activates the sarcoplasmic reticulum via which receptors?...

    Incorrect

    • Depolarization of the T tubule membrane activates the sarcoplasmic reticulum via which receptors?

      Your Answer: Ryanodine receptors

      Correct Answer: Dihydropyridine receptors

      Explanation:

      Action potentials are transmitted to the fibrils of a fiber through the T tubule system. It triggers the release of Ca 2+ form the terminal cisterns. Depolarization of the T tubules activates the sarcoplasmic reticulum through the dihydropyridine receptors.

      Dihydropyridine receptors (DHPRs), are voltage-gated Ca2+ channels, and ryanodine receptors (RyRs), which are intracellular Ca2+ release channels, are expressed in diverse cell types, including skeletal and cardiac muscle.

      Ryanodine receptors (RyRs) are located in the sarcoplasmic/endoplasmic reticulum membrane and are responsible for the release of Ca2+ from intracellular stores during excitation-contraction coupling in both cardiac and skeletal muscle.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      10.9
      Seconds

  • Question 9 - 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
      20.6
      Seconds

  • Question 10 - When observing a JVP, which of the following would lead to prominent v...

    Correct

    • When observing a JVP, which of the following would lead to prominent v waves?

      Your Answer: Tricuspid regurgitation

      Explanation:

      The v wave corresponds to Venous filling when the tricuspid valve is closed and venous pressure increases from venous return. In Tricuspid regurgitation there is additional blood from the regurgitant flow and thus this leads to a more prominent V wave.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      51.7
      Seconds

  • Question 11 - Absolute refractory period in a cardiac action potential graph occurs during. ...

    Incorrect

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

      Your Answer: Initial rapid repolarization

      Correct 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
      12.2
      Seconds

  • Question 12 - Which is the commonest cardiovascular abnormality seen in an adult patient with Marfan’s...

    Incorrect

    • Which is the commonest cardiovascular abnormality seen in an adult patient with Marfan’s syndrome?

      Your Answer: Mitral regurgitation

      Correct Answer: Aortic aneurysm

      Explanation:

      Marfan syndrome (MFS) is a genetic disorder of connective tissue. The degree to which people are affected varies. People with Marfan’s tend to be tall, and thin, with long arms, legs, fingers and toes. They also typically have flexible joints and scoliosis. The most serious complications involve the heart and aorta with an increased risk of mitral valve prolapse and aortic aneurysm.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      6.9
      Seconds

  • Question 13 - Select the correct statement regarding the 4th heart sound, it? ...

    Incorrect

    • Select the correct statement regarding the 4th heart sound, it?

      Your Answer: Coincides with rapid ventricular filling.

      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
      13.4
      Seconds

  • Question 14 - The major factor in controlling coronary artery blood flow is considered to be?...

    Correct

    • The major factor in controlling coronary artery blood flow is considered to be?

      Your Answer: Metabolites of oxygen consumption

      Explanation:

      There is a strong relationship between myocardial blood flow and oxygen consumption. This indicates that products of metabolism may cause vasodilation of the coronary artery.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      20.6
      Seconds

  • Question 15 - 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 2nd left costal cartilage to the 3rd right 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
      19.9
      Seconds

  • Question 16 - The coronary arteries supply which part of the heart’s subendocardial region exclusively in...

    Correct

    • The coronary arteries supply which part of the heart’s subendocardial region exclusively in diastole?

      Your 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
      27.1
      Seconds

  • Question 17 - Which of the atrial pressure changes represents the a-wave of the JVP ...

    Correct

    • Which of the atrial pressure changes represents the a-wave of the JVP

      Your Answer: Atrial systole

      Explanation:

      The a-wave created on the venous pulse curve occurs as a result of atrial systole. Due to the pressure build-up in the atria, it causes a back pressure in the vena cava. This pressure is exerted on the valve and this back pressure is what causes a slight increase in the venous pressure.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      14.8
      Seconds

  • Question 18 - The ‘c’ wave in JVP corresponds more closely with: ...

    Correct

    • The ‘c’ wave in JVP corresponds more closely with:

      Your Answer: Isovolumetric contraction

      Explanation:

      The jugular venous pressure (JVP, sometimes referred to as jugular venous pulse) is the indirectly observed pressure over the venous system via visualization of the internal jugular vein. It can be useful in the differentiation of different forms of heart and lung disease. Classically three upward deflections (peaks) and two downward deflections (troughs) have been described: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
      6.9
      Seconds

  • Question 19 - Xanthines such as caffeine and theophylline are positively inotropic due to: ...

    Correct

    • Xanthines such as caffeine and theophylline are positively inotropic due to:

      Your Answer: Inhibition of cAMP breakdown

      Explanation:

      Xanthines exert their positive inotropic effect by inhibiting the breakdown of the cAMP resulting in stronger and sustained contractions.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      30.4
      Seconds

  • Question 20 - The steps of cardiac cycle in sequence are: ...

    Correct

    • The steps of cardiac cycle in sequence are:

      Your Answer: Isovolumic contraction, ejection, isovolumic relaxation, passive ventricular filling, active ventricular filling.

      Explanation:

      The cardiac cycle refers to a complete heartbeat from its generation to the beginning of the next beat, and so includes the diastole, the systole, and the intervening pause.1st stage: diastole, or passive filling is when the semilunar valves (the pulmonary valve and the aortic valve) close, the atrioventricular (AV) valves (the mitral valve and the tricuspid valve) open, and the whole heart is relaxed. 2nd stage: atrial systole, is when the atrium contracts, and blood flows from atrium to the ventricle (active filling).3rd stage: isovolumic contraction is when the ventricles begin to contract, the AV and semilunar valves close, and there is no change in volume. 4th stage: ventricular ejection, is when the ventricles are contracting and emptying, and the semilunar valves are open. 5th stage: isovolumic relaxation time, pressure decreases, no blood enters the ventricles, the ventricles stop contracting and begin to relax, and the semilunar valves close due to the pressure of blood in the aorta.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      78.3
      Seconds

  • Question 21 - The Wiebel-Palade body found in the endothelial cells is responsible for the production...

    Correct

    • The Wiebel-Palade body found in the endothelial cells is responsible for the production and release of which factor?

      Your Answer: Von Willebrand factor

      Explanation:

      Weibel-Palade bodies are the storage granules of endothelial cells, the cells that form the inner lining of the blood vessels and heart. They store and release two principal molecules, von Willebrand factor and P-selectin, and thus play a dual role in haemostasis and inflammation.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      12.9
      Seconds

  • Question 22 - Which one of the following is a cause of a soft second heart...

    Incorrect

    • Which one of the following is a cause of a soft second heart sound?

      Your Answer: Aortic regurgitation

      Correct Answer: Aortic stenosis

      Explanation:

      Second heart sound (S2) forms the dub of lub-dub and is composed of components A2 and P2. •    loud: hypertension•    soft: AS•    fixed split: physiological split (normally occurs during inhalation), right bundle branch block, pulmonary stenosis, and atrial septal defect.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      86.1
      Seconds

  • Question 23 - In a 30 year old male with hypertrophic obstructive cardiomyopathy (HOCM), which of...

    Correct

    • In a 30 year old male with hypertrophic obstructive cardiomyopathy (HOCM), which of the following is not associated with increased risk of sudden death?

      Your Answer: Age

      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. The major risk factors for sudden death (SD) are recent unexplained syncope unlikely to be neurocardiogenic; HCM-related SD in first-degree or other close relatives; repetitive and/or prolonged nonsustained ventricular tachycardia (NSVT) episodes on Holter or extended ambulatory monitoring; massive left ventricular hypertrophy (LVH) (wall thickness ≥30 mm); extensive/diffuse late gadolinium enhancement (LGE); end-stage heart failure usually with systolic dysfunction; and thin-walled akinetic LV apical aneurysm with regional scarring.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      33.4
      Seconds

  • Question 24 - Generalized vasoconstrictors include: ...

    Correct

    • Generalized vasoconstrictors include:

      Your 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
      19.6
      Seconds

  • Question 25 - In Starling’s law of the heart, the decrease in tension developed by muscle...

    Incorrect

    • In Starling’s law of the heart, the decrease in tension developed by muscle contraction at high degrees of stretch is due to:

      Your Answer: A conformational change in the myosin head at high degrees of stretch.

      Correct Answer: Disruption of myocardial fibers

      Explanation:

      Starling law states that the force of contraction is directly proportional to the preload. When the heart muscle is stretched beyond its limit the tension that is developed decreases, this is not due to loss of formation of effective myosin and actin cross bridges. The heart muscles despite being fully stretched is never stretched to this point. The reason for this decreased tension is physical disruption of the myocardial fibers.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      20.9
      Seconds

  • Question 26 - Which of the following supplies the AV node? ...

    Incorrect

    • Which of the following supplies the AV node?

      Your Answer: Both circumflex and left anterior descending

      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
      • Medicine
      17.4
      Seconds

  • Question 27 - Regarding the length of systole and diastole which of the following is true?...

    Incorrect

    • Regarding the length of systole and diastole which of the following is true?

      Your Answer: Cardiac muscle can be tetanise

      Correct Answer: The duration of systole is more fixed than diastole

      Explanation:

      The duration of systole is more fixed than the duration of diastole. When the heart rate increases the timing of systole remains more or less the same however, diastole decreases.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      31.2
      Seconds

  • Question 28 - All of the following are consistent with the indicator dilution method except--- ...

    Correct

    • All of the following are consistent with the indicator dilution method except---

      Your 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
      22.3
      Seconds

  • Question 29 - Which of the following are responsible for the 4th heart sound? ...

    Incorrect

    • Which of the following are responsible for the 4th heart sound?

      Your Answer: Rapid ventricular filling

      Correct Answer: Ventricular hypertrophy

      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 in atrial systole.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      5.5
      Seconds

  • Question 30 - Myocardial fibers have a resting membrane potential of approximately: ...

    Incorrect

    • Myocardial fibers have a resting membrane potential of approximately:

      Your Answer: -60mv

      Correct Answer: -90mv

      Explanation:

      The resting membrane potential of the mammalian heart is about -90 mv.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      175.3
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (17/30) 57%
Medicine (17/30) 57%
Passmed
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