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  • Question 1 - Pacemaker cells in the SA node and the AV node are connected by?...

    Correct

    • Pacemaker cells in the SA node and the AV node are connected by?

      Your 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
      17.9
      Seconds

  • Question 2 - Blood flow to the subendocardial portions of the left ventricular muscle occurs mainly...

    Correct

    • Blood flow to the subendocardial portions of the left ventricular muscle occurs mainly during:

      Your Answer: Diastole

      Explanation:

      The sub endocardium receives the least amount of blood from the coronary arteries. During systole the coronary arteries collapse as a result of the pressure from 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 sub endocardium.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      9.9
      Seconds

  • Question 3 - Activation of nitric oxide synthesis by endothelial cells is triggered by: ...

    Correct

    • Activation of nitric oxide synthesis by endothelial cells is triggered by:

      Your Answer: All of the above

      Explanation:

      Acetylcholine, histamine, bradykinin, vasoactive intestinal peptide (VIP) and shear stress on the endothelial cells causing the release of NO. NO is formed from arginine and causes vasodilatation of the blood vessels.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      48.6
      Seconds

  • Question 4 - 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
      22.3
      Seconds

  • Question 5 - What is cardiac output? ...

    Correct

    • What is cardiac output?

      Your Answer: Product of stroke volume and heart rate

      Explanation:

      Cardiac output is the product of stroke volume and heart rate.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      5.2
      Seconds

  • Question 6 - Which of the following isoforms of Nitric oxide synthase (NOS) is found in...

    Incorrect

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

      Your Answer: Nos 2

      Correct 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
      8.4
      Seconds

  • Question 7 - The process by which depolarization of the muscle fiber initiates contraction is called?...

    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
      16.6
      Seconds

  • Question 8 - Which structure forms the major part of the sternocostal surface of the heart?...

    Correct

    • Which structure forms the major part of the sternocostal surface of the heart?

      Your Answer: Right ventricle

      Explanation:

      The anterior (sternocostal) surface is formed mainly by the right ventricle.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      15.3
      Seconds

  • Question 9 - Regarding cardiac muscle contractility, the afterload refers to: ...

    Correct

    • Regarding cardiac muscle contractility, the afterload refers to:

      Your Answer: The resistance against which blood is expected

      Explanation:

      The afterload for the left ventricle is the aortic pressure. Hence it is this pressure that offers resistance against which the blood is to be expelled from the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      26.7
      Seconds

  • Question 10 - Tunica intima is made up of? ...

    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
      21.8
      Seconds

  • Question 11 - In the jugular venous pressure wave… ...

    Incorrect

    • In the jugular venous pressure wave…

      Your Answer: ‘v’ wave coincide with rapid ventricular filling phase

      Correct Answer: Consists of 3 peaks and 2 troughs

      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
      20.7
      Seconds

  • Question 12 - What type of intercellular connection found between cardiac muscle fibers allow for the...

    Correct

    • What type of intercellular connection found between cardiac muscle fibers allow for the spread of excitation from one cell to another?

      Your Answer: Gap junctions

      Explanation:

      The cardiac muscles have gap junctions in-between the cells. They form 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
      • Medicine
      10.1
      Seconds

  • Question 13 - During exercise, a man consumes 2L O2/min, his arterial 02 content is 190...

    Incorrect

    • During exercise, a man consumes 2L O2/min, his arterial 02 content is 190 ml/l and the 02 content of his mixed venous blood is 130ml/l. His cardiac output is approximately:

      Your Answer: 3,3 l/min

      Correct Answer: 33l/min

      Explanation:

      In Fick’s original method, the following variables are measured:VO2, oxygen consumption in ml of pure gaseous oxygen per minute. This may be measured using a spirometer within a closed rebreathing circuit incorporating a CO2 absorberCa, the oxygen concentration of blood taken from the pulmonary vein (representing oxygenated blood)Cv, the oxygen concentration of blood from an intravenous cannula (representing deoxygenated blood)From these values, we know that:VO2 = (CO x Ca) – (CO x Cv)where CO = Cardiac Output, Ca = Oxygen concentration of arterial blood and Cv = Oxygen concentration of mixed venous blood.This allows us to sayCO = VO2/{Ca – Cv}and hence calculate cardiac output.Therefore CO = 2/(0.190-0.130) = 33l/minNote that (Ca – Cv) is also known as the arteriovenous oxygen difference.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      154
      Seconds

  • Question 14 - The rate of depolarization of the SA node membrane potential is modulated by...

    Correct

    • The rate of depolarization of the SA node membrane potential is modulated by the following:

      Your Answer: All of the above

      Explanation:

      Rate of depolarization of the SA node is modulated by all of these.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      15.5
      Seconds

  • Question 15 - Which of the following conditions has no effect on cardiac output? ...

    Incorrect

    • Which of the following conditions has no effect on cardiac output?

      Your Answer: Posture/body position

      Correct Answer: Sleep

      Explanation:

      Sleep has no effect on the cardiac output. Anxiety, excitement 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
      21.3
      Seconds

  • Question 16 - All of the following are consistent with the indicator dilution method except--- ...

    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
      25.9
      Seconds

  • Question 17 - The predominant receptors in the hearts conduction system are? ...

    Correct

    • The predominant receptors in the hearts conduction system are?

      Your Answer: Β1

      Explanation:

      All of the components of the intrinsic conduction system contain autorhythmic cells that spontaneously depolarize. In the absence of extrinsic neural or hormonal influences, the SA node pacing rate would be about 100 beats per minute (bpm). The heart rate and cardiac output, however, must vary in response to the needs of the body’s cells for oxygen and nutrients under varying conditions. In order to respond rapidly to changing requirements of the body’s tissues, the heart rate and contractility are regulated by the autonomic nervous system (ANS), hormones, and other factors. The ANS has two interacting systems: the sympathetic and parasympathetic systems. Sympathetic receptors: There are two types of adrenergic receptors: β and α. In the cardiovascular system there are β1, β2, α1, and α2 adrenergic receptors. β1 adrenergic receptors are expressed in the heart conduction system (in the SA node, AV node, and on atrial and ventricular cardiomyocytes). The activation of β1 receptors increases heart rate (via the SA node), and contractility.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      11
      Seconds

  • Question 18 - Regarding the myofilament molecules, which of the following contains binding sites for calcium...

    Incorrect

    • Regarding the myofilament molecules, which of the following contains binding sites for calcium that helps to initiate contraction?

      Your Answer: Actinin

      Correct Answer: Troponin c

      Explanation:

      Troponin T binds the troponin components to tropomyosin. Troponin I inhibits the interaction of myosin with actin and troponin C contains the binding sites for the Ca2+ that helps initiate contraction.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      21.7
      Seconds

  • Question 19 - Concerning surface anatomy, where is the base of the heart ...

    Correct

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

      Your 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
      41.4
      Seconds

  • Question 20 - Which coronary artery supplies the right atria? ...

    Correct

    • Which coronary artery supplies the right atria?

      Your Answer: Right coronary

      Explanation:

      The left coronary artery distributes blood to the left side of the heart, the left atrium and ventricle, and the interventricular septum. The circumflex artery arises from the left coronary artery and follows the coronary sulcus to the left. Eventually, it will fuse with the small branches of the right coronary artery. The right coronary artery proceeds along the coronary sulcus and distributes blood to the right atrium, portions of both ventricles, and the heart conduction system.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      10.8
      Seconds

  • Question 21 - Which of the following intercellular connections is important in endothelial barrier function? ...

    Correct

    • Which of the following intercellular connections is important in endothelial barrier function?

      Your Answer: Tight junctions

      Explanation:

      Tight junctions surround the apical margins of the epithelial cells such as in the intestinal mucosa and the choroid plexus. They are also important to the endothelial barrier function. They are made up of ridges that adhere to each other strongly at the cell junction, obliterating the space completely between the cells.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      11.1
      Seconds

  • Question 22 - Xanthines such as caffeine and theophylline are positively inotropic due to: ...

    Incorrect

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

      Your Answer: Circulating catecholamines

      Correct 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
      10.7
      Seconds

  • Question 23 - Which of the following corresponds to an oblique line drawn from the sternal...

    Correct

    • Which of the following corresponds to an oblique line drawn from the sternal end of the left 3rd costal cartilage to the sternal end of the right 6th costal cartilage?

      Your Answer: Atrio-ventricular (coronary) groove

      Explanation:

      The AV groove corresponds to the right border of the heart. 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
      103.9
      Seconds

  • Question 24 - Depolarization of the T tubule membrane activates the sarcoplasmic reticulum via which receptors?...

    Correct

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

      Your 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. They are voltage gated calcium channels.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      25.6
      Seconds

  • Question 25 - Which of the following is true of the Natriuretic hormones? ...

    Incorrect

    • Which of the following is true of the Natriuretic hormones?

      Your Answer: They are released in response to hypervolemia

      Correct Answer:

      Explanation:

      Natriuretic hormones are vasodilators released in response to hypervolemia

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      27
      Seconds

  • Question 26 - Why does arterial blood pressure drop during pregnancy? ...

    Correct

    • Why does arterial blood pressure drop during pregnancy?

      Your Answer: Progesterone relaxes vascular smooth muscle

      Explanation:

      Progesterone relaxes vascular smooth muscle thus resulting In a decrease in total peripheral resistance. This accounts for the increase in the cardiac output.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      10.8
      Seconds

  • Question 27 - Which of the following suggests the presence of mitral regurgitation as well as...

    Correct

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

      Your 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
      16.3
      Seconds

  • Question 28 - 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
      3.2
      Seconds

  • Question 29 - Which of the following does not contribute to increased stroke volume during exercise?...

    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
      28
      Seconds

  • Question 30 - Myocyte action potentials – Choose the false statement: ...

    Incorrect

    • Myocyte action potentials – Choose the false statement:

      Your Answer: The initial rapid depolarisation (phase 0) is due to Na+ influx

      Correct Answer: Repolarisation is due to net k+ influx

      Explanation:

      Final repolarization (phase 3) to the resting membrane potential (phase 4) is due to closure of the Ca2+ channels and a slow, delayed increase of K+ efflux through various types of K+ channels.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      19.3
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (19/30) 63%
Medicine (19/30) 63%
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