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  • Question 1 - The coronary sinus drains into the: ...

    Incorrect

    • The coronary sinus drains into the:

      Your Answer: Left atrium

      Correct Answer: Right atrium

      Explanation:

      The coronary sinus drains into the right atrium. 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.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      12.2
      Seconds

  • Question 2 - The function of Troponin T in cardiac muscle is? ...

    Correct

    • The function of Troponin T in cardiac muscle is?

      Your Answer: Allows attachment of troponin components to tropomyosin

      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
      20.5
      Seconds

  • Question 3 - Myocardial oxygen consumption is increased by: ...

    Correct

    • Myocardial oxygen consumption is increased by:

      Your Answer: An increase in after load

      Explanation:

      Cardiac oxygen consumption is directly related to the amount of tension that develops in the ventricles. It is increased by an increased size of heart, increased afterload, increased contractility and increased heart rate.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      17.7
      Seconds

  • Question 4 - In the blood supply of the heart, ‘dominance’ refers to the coronary artery...

    Correct

    • In the blood supply of the heart, ‘dominance’ refers to the coronary artery which supplies the?

      Your Answer: Posterior interventricular artery

      Explanation:

      Dominance of the coronary artery system is defined by the artery that gives rise to the posterior interventricular artery. Dominance of the right coronary artery is more common (68%). It gives rise to the large posterior interventricular branch which goes down to the apex of the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      13
      Seconds

  • Question 5 - Adrenergic stimulation will lead to myocyte relaxation via the following mechanisms ...

    Correct

    • Adrenergic stimulation will lead to myocyte relaxation via the following mechanisms

      Your Answer: Increased phosphorylation of phosholamban

      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
      39.4
      Seconds

  • Question 6 - If both the noradrenergic and the cholinergic systems are blocked in the heart,...

    Incorrect

    • If both the noradrenergic and the cholinergic systems are blocked in the heart, the rate will be approximately:

      Your Answer: 140/min

      Correct Answer: 100/min

      Explanation:

      The normal heart beat is about 70/min. This is due to a predominant parasympathetic activity. If sympathetic activity was unopposed the heart rate would have been 150/min. When both the noradrenergic and cholinergic systems are blocked the heart rate is 100/min. This is the normal firing rate of the SA node.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      15.7
      Seconds

  • Question 7 - 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
      10.6
      Seconds

  • Question 8 - The coronary arteries supply which part of the heart’s subendocardial region exclusively in...

    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
      49
      Seconds

  • Question 9 - The following determines the strength of contraction ...

    Incorrect

    • The following determines the strength of contraction

      Your Answer: Partial repolarisation

      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
      • Medicine
      19.2
      Seconds

  • Question 10 - Calcium induced calcium release occurs in the sarcoplasmic reticulum by activation of which...

    Correct

    • Calcium induced calcium release occurs in the sarcoplasmic reticulum by activation of which receptors

      Your Answer: Ryanodine receptors

      Explanation:

      Calcium-induced calcium release (CICR) describes a biological process whereby calcium is able to activate calcium release from intracellular Ca2+ stores (e.g., endoplasmic reticulum or sarcoplasmic reticulum). CICR occurs when the resulting Ca2+ influx activates ryanodine receptors on the SR membrane, which causes more Ca2+ to be released into the cytosol.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      14.4
      Seconds

  • Question 11 - 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: Atrial fibrillation

      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
      21.3
      Seconds

  • Question 12 - Angina pectoris develops when blood through the coronary artery becomes: ...

    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
      13.8
      Seconds

  • Question 13 - 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: Troponin t

      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
      28.7
      Seconds

  • Question 14 - When is the blood pressure at its lowest during pregnancy? ...

    Incorrect

    • When is the blood pressure at its lowest during pregnancy?

      Your Answer: First trimester

      Correct Answer: Second trimester

      Explanation:

      It is lowest during the second trimester.

      Previous studies have reported changes in blood pressure (BP) throughout pregnancy, and it was generally accepted that in clinically healthy pregnant women, BP falls gradually at first trimester, reaching the lowest around 22–24 weeks, rising again from 28 weeks, and reaching preconception levels by 36 weeks of gestation

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      14.2
      Seconds

  • Question 15 - The following contributes to the rate of depolarization? ...

    Incorrect

    • The following contributes to the rate of depolarization?

      Your Answer: Stretch

      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
      11.1
      Seconds

  • Question 16 - According to Poiseuille’s formula, which 1 of the following will lead to increased...

    Incorrect

    • According to Poiseuille’s formula, which 1 of the following will lead to increased flow?

      Your Answer: Less turbulent flow

      Correct Answer: Shorter tube

      Explanation:

      V = π p r4 / 8 η lwhere V = discharge volume flow (m3/s)p = pressure difference between the ends of the pipe (N/m2, Pa)r = internal radius of pipe (m)l = length of pipe (m)η = viscosity of fluid

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      24.4
      Seconds

  • Question 17 - Catecholamines… ...

    Correct

    • Catecholamines…

      Your Answer: Activate adenylyl cyclase

      Explanation:

      Norepinephrine and epinephrine activate or deactivate adenylyl cyclase resulting in a decrease or an increase in the production of cAMP.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      21
      Seconds

  • Question 18 - Factors influencing cardiac output include which of the following? ...

    Incorrect

    • Factors influencing cardiac output include which of the following?

      Your Answer: Stroke volume

      Correct 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
      10.2
      Seconds

  • Question 19 - Which of the following best describes the cardiac muscle? ...

    Correct

    • Which of the following best describes the cardiac muscle?

      Your Answer: Striated and involuntary

      Explanation:

      Cardiac muscle (heart muscle) is an involuntary, striated muscle that is found in the walls and histological foundation of the heart, specifically the myocardium. Cardiac muscle is one of three major types of muscle, the others being skeletal and smooth muscle.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      15.2
      Seconds

  • Question 20 - Which of the following normally has a slow depolarizing “prepotential”? ...

    Incorrect

    • Which of the following normally has a slow depolarizing “prepotential”?

      Your Answer: Bundle of his

      Correct Answer: Sinoatrial node

      Explanation:

      There are 2 main types of action potentials (AP) in the heart, the slow response and the fast response:The slow response is initiated by the slow calcium-sodium channels, found in the SA node (which is the natural pacemaker of the heart) and the conduction fibers of the AV node.The fast response occurs in the atrial and ventricles muscle cells and the purkinje fibers.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      13.2
      Seconds

  • Question 21 - 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 4

      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
      7.6
      Seconds

  • Question 22 - Heart rate can be slowed by: ...

    Incorrect

    • Heart rate can be slowed by:

      Your Answer: Inspiration

      Correct Answer: Grief

      Explanation:

      Grief stimulates the parasympathetic nervous system, resulting in a decrease in the heart rate.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      23.6
      Seconds

  • Question 23 - Which one of the following is a risk factor for torsade de pointes?...

    Incorrect

    • Which one of the following is a risk factor for torsade de pointes?

      Your Answer: Hypercalcaemia

      Correct Answer: Hypothermia

      Explanation:

      The following is a list of factors associated with an increased tendency toward torsades de pointes:- Hypokalaemia (low blood potassium)- Hypomagnesemia (low blood magnesium)- Hypocalcaemia (low blood calcium)- Bradycardia (slow heartbeat)- Heart failure- Left ventricular hypertrophy- Hypothermia- Subarachnoid haemorrhage- Hypothyroidism

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      7.8
      Seconds

  • Question 24 - Direct conduction from the atrium to the ventricles is prevented by: ...

    Correct

    • Direct conduction from the atrium to the ventricles is prevented by:

      Your Answer: Annulus fibrosus

      Explanation:

      The annulus fibrosus disconnects the syncytium complex. The atria are rapidly activated however the activation peters out when the insulating layer-the annulus fibrosus-is reached.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      20.7
      Seconds

  • Question 25 - Regarding the length of systole and diastole which of the following is true?...

    Correct

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

      Your 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
      24.6
      Seconds

  • Question 26 - 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
      25
      Seconds

  • Question 27 - The end- diastolic ventricular volume is about? ...

    Correct

    • The end- diastolic ventricular volume is about?

      Your Answer: 130 ml

      Explanation:

      The end diastolic volume in a healthy individual is about 130 ml.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      9.3
      Seconds

  • Question 28 - Hyperkalaemia [K+ =7meq/l] can lead to the following ECG changes [Ca++ normal] ...

    Correct

    • Hyperkalaemia [K+ =7meq/l] can lead to the following ECG changes [Ca++ normal]

      Your Answer: Peaked T waves

      Explanation:

      Hyperkalaemia causes the formation of tall tented T waves due to altered repolarization.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      8
      Seconds

  • Question 29 - Ventricular depolarization plus ventricular repolarization is shown by the _____ interval ...

    Incorrect

    • Ventricular depolarization plus ventricular repolarization is shown by the _____ interval

      Your Answer: QRS

      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
      8.9
      Seconds

  • Question 30 - 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
      14.8
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (13/30) 43%
Medicine (13/30) 43%
Passmed
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