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  • Question 1 - The following is true in relation to coronary venous drainage? ...

    Correct

    • The following is true in relation to coronary venous drainage?

      Your Answer: Most venous return ultimately drains into right atrium via the coronary sinus

      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

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      7
      Seconds

  • Question 2 - According to Poiseuille’s formula, which 1 of the following will lead to increased...

    Correct

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

      Your 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
      4.1
      Seconds

  • Question 3 - Which of the following antiarrhythmic drugs may be used in the treatment of...

    Incorrect

    • Which of the following antiarrhythmic drugs may be used in the treatment of long QT syndrome?

      Your Answer: Flecainide

      Correct Answer: Atenolol

      Explanation:

      Beta-blockers are the mainstay of treatment in long QT syndrome. Implantable cardioverter-defibrillators are the most effective treatment in genotypes with a high risk of recurrence.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      10.5
      Seconds

  • Question 4 - Coronary vasoconstriction can be caused by: ...

    Incorrect

    • Coronary vasoconstriction can be caused by:

      Your Answer: Vagal tone

      Correct Answer: Beta blockage

      Explanation:

      Coronary arteries contain alpha and beta receptors. The alpha receptor stimulates vasoconstriction and beta receptors stimulate vasodilation. When the chronotropic and inotropic effects of noradrenergic receptors are blocked by a B blocking drug, stimulation of the noradrenergic nerves will cause coronary vasoconstriction.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      9.5
      Seconds

  • Question 5 - The areas of extensive series of sarcoplasmic folds known as intercalated discs always...

    Correct

    • The areas of extensive series of sarcoplasmic folds known as intercalated discs always occur at what portion of the muscle fiber?

      Your Answer: Z lines

      Explanation:

      The muscle fibers of the heart branch and interdigitate, but one complete unit is surrounded by a cell membrane. The place where one muscle fiber abuts the other, the cell membrane of both the fibers run parallel to each other through a series of extensive folds. These areas always occur on the Z lines and are known as intercalated discs.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      6.7
      Seconds

  • Question 6 - The rate of depolarisation of the sinus node membrane potential is modulated by...

    Incorrect

    • The rate of depolarisation of the sinus node membrane potential is modulated by all the following except:

      Your Answer: Hormonal influences

      Correct Answer: Cardiac output

      Explanation:

      Cardiac output has no effect on the depolarization of the pacemaker potential of the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      6.7
      Seconds

  • Question 7 - Concerning surface anatomy, where is the aortic valve found? ...

    Incorrect

    • Concerning surface anatomy, where is the aortic valve found?

      Your Answer: Situated in the right second intercostal space underneath the sternum

      Correct Answer: Situated in the left third intercostal space underneath the sternum

      Explanation:

      The aortic valve is situated in the left 3rd intercostal space just beneath the sternum.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      29.1
      Seconds

  • Question 8 - The T-tubular system in cardiac muscle is: ...

    Correct

    • The T-tubular system in cardiac muscle is:

      Your Answer: Transmits action potential from sarcolemma to the SR to allow for Ca2+ release into the cytoplasm

      Explanation:

      Action potentials are 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, which are voltage gated calcium channels.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      13.8
      Seconds

  • Question 9 - The following contributes to the rate of depolarization? ...

    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
      3.9
      Seconds

  • Question 10 - Depolarization spreads rapidly through cardiac muscle fibers because of the presence of: ...

    Correct

    • Depolarization spreads rapidly through cardiac muscle fibers because of the presence of:

      Your Answer: Gap junctions

      Explanation:

      The cardiac muscles have gap junctions in between the cells. They allow for the formation of 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
      3.6
      Seconds

  • Question 11 - The hyperpolarization phase of pacemaker cells is dominated by ____ current. ...

    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
      3.4
      Seconds

  • Question 12 - The end- diastolic ventricular volume is about? ...

    Incorrect

    • The end- diastolic ventricular volume is about?

      Your Answer: 70 ml

      Correct 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
      13.7
      Seconds

  • Question 13 - Transport of Ca2+ into the reticulum to initiate cardiac muscle relaxation in via:...

    Incorrect

    • Transport of Ca2+ into the reticulum to initiate cardiac muscle relaxation in via:

      Your Answer: Voltage-gated Ca2+ channels

      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
      14.1
      Seconds

  • Question 14 - Which of the following results in the resting membrane potential of a myocyte?...

    Correct

    • Which of the following results in the resting membrane potential of a myocyte?

      Your Answer: Activation of outward K+ channels

      Explanation:

      Phase 0 is caused by the sodium current. Voltage gated sodium channels open leading to the influx of sodium into the cardiac muscle cell. Phase 1 is the rapid transient repolarization phase which is caused by the inactivation of the voltage gated sodium channels and opening of the voltage gated potassium channels along with opening of the slow calcium channels. Phase 2 which is the plateau is caused by opening of the slow calcium channels. Phase 4 is caused by closing of the slow calcium channels and opening of the potassium channels leading to efflux of potassium leading to the establishment of the resting membrane potential.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.8
      Seconds

  • Question 15 - The following determines the strength of contraction ...

    Correct

    • The following determines the strength of contraction

      Your 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
      5.1
      Seconds

  • Question 16 - Tunica intima is made up of? ...

    Incorrect

    • Tunica intima is made up of?

      Your Answer: Endothelial cells and 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
      3.6
      Seconds

  • Question 17 - With regard to the endothelial structure, the epithelium constitute: ...

    Incorrect

    • With regard to the endothelial structure, the epithelium constitute:

      Your Answer: Stratified columnar

      Correct Answer: Simple squamous

      Explanation:

      The single layer of squamous epithelium lining the heart and blood vessels is known as the endothelium.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      6.4
      Seconds

  • Question 18 - Although variable, branches of which artery most often supply the SA and AV...

    Correct

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

      Your 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
      3.5
      Seconds

  • Question 19 - Which of the following conditions has no effect on cardiac output? ...

    Correct

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

      Your 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
      3.5
      Seconds

  • Question 20 - 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
      17.2
      Seconds

  • Question 21 - Which of the following causes the closure of the ductus arteriosus during birth?...

    Incorrect

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

      Your Answer: Increased levels of prostaglandins

      Correct 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
      3.4
      Seconds

  • Question 22 - The amount of a substance taken up by an organ (or whole body)...

    Incorrect

    • The amount of a substance taken up by an organ (or whole body) per unit time is = (the arterial level - the venous level) * the blood flow. This statement describes?

      Your Answer: The indicator dilution principle

      Correct Answer: The Fick principle

      Explanation:

      The essence of the Fick principle is that blood flow to an organ can be calculated using a marker substance if the following information is known:- Amount of marker substance taken up by the organ per unit time- Concentration of marker substance in arterial blood supplying the organ- Concentration of marker substance in venous blood leaving the organ

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      16
      Seconds

  • Question 23 - Initial depolarization of cardiac muscle is due to influx of: ...

    Correct

    • Initial depolarization of cardiac muscle is due to influx of:

      Your Answer: Na+

      Explanation:

      Initial depolarization of the cardiac muscle results from opening of the sodium voltage gated channels. This results in the influx of sodium and an increase in the membrane potential towards threshold. Potassium efflux results in repolarization.

      The cardiac action potential has 5 phases:

      • Phase 0—depolarization because of the opening of fast sodium channels. Potassium flux also decreases.
      • Phase 1—partial repolarization because of a rapid decrease in sodium ion passage as fast sodium channels close.
      • Phase 2—plateau phase in which the movement of calcium ions out of the cell, maintains depolarization.
      • Phase 3—repolarization, sodium, and calcium channels all close and membrane potential returns to baseline.
      • Phase 4—resting membrane potential (−90 mV), resulting from the activity of the Na+/K+ ATPase pump which creates a negative intracellular potential because of the exchange of three sodium ions for only two potassium ions.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      2.4
      Seconds

  • Question 24 - 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
      5.6
      Seconds

  • Question 25 - Dicrotic notch is produced by which valves? ...

    Correct

    • Dicrotic notch is produced by which valves?

      Your Answer: Aortic

      Explanation:

      The graph of aortic pressure throughout the cardiac cycle displays a small dip (the incisure or dicrotic notch) which coincides with the aortic valve closure. The dip in the graph is immediately followed by a brief rise (the dicrotic wave) then gradual decline.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      2.1
      Seconds

  • Question 26 - In the jugular venous pressure wave… ...

    Correct

    • In the jugular venous pressure wave…

      Your 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
      6.6
      Seconds

  • Question 27 - Which ion channel does not contribute to the myocardial action potential? ...

    Correct

    • Which ion channel does not contribute to the myocardial action potential?

      Your Answer: Chloride channel

      Explanation:

      The upstroke in the cardiac action potential is due to opening of the sodium channels and an influx of sodium into the cell. The initial repolarization phase is due to transient opening of the potassium channels along with calcium channels. Influx of calcium causes the prolonged plateau phase of the action potential. Delayed opening of the rectifier potassium channel and delayed closure of the calcium channel leads to the repolarization phase of cardiac action potential.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      2.9
      Seconds

  • Question 28 - The celiac trunk consists of which arteries? ...

    Incorrect

    • The celiac trunk consists of which arteries?

      Your Answer: Right gastric, common hepatic, superior mesenteric

      Correct Answer: Left gastric, common hepatic, splenic

      Explanation:

      The celiac trunk is the first major branch of the abdominal aorta. It is 1.25 cm in length. Branching from the aorta at thoracic vertebra 12 (T12). There are three main divisions of the celiac artery:- left gastric artery- common hepatic artery- splenic artery

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      8.8
      Seconds

  • Question 29 - Describe the location of the SA node: ...

    Incorrect

    • Describe the location of the SA node:

      Your Answer: Base of the right atrium

      Correct Answer: Junction of the SVC and right atrium

      Explanation:

      Anatomically the SA node is located at the junction of the superior vena cava and the right atrium.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      11.4
      Seconds

  • Question 30 - With regards to the cardiac cycle which of the following is true ...

    Incorrect

    • With regards to the cardiac cycle which of the following is true

      Your Answer:

      Correct Answer: Right atrial systole occurs before left atrial systole: as below

      Explanation:

      Cardiac cycle: The first event in the cycle is atrial depolarization (a P wave on the surface ECG) follows by RIGHT ATRIAL and then LEFT ATRIAL contraction. Ventricular activation (QRS) follows after a short interval (the PR interval). LEFT VENTRICULAR contraction starts shortly thereafter RIGHT VENTRICULAR contraction begins. At the end, the aortic valve closure is followed by pulmonary valve closure.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (17/29) 59%
Medicine (17/29) 59%
Passmed
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