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  • Question 1 - Concerning surface anatomy, where is the aortic valve found? ...

    Incorrect

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

      Your Answer: Situated in the left four intercostal space left to 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
      39.6
      Seconds

  • Question 2 - B1 adrenergic stimulation produces: ...

    Correct

    • B1 adrenergic stimulation produces:

      Your Answer: Increase in calcium cytosolic concentration

      Explanation:

      Norepinephrine secreted by the sympathetic endings binds to B1 receptors, and the resulting increase in intracellular cAMP facilitates the opening of L channels, increasing Ica and the rapidity of the depolarization phase of the impulse and activates PKA which leads to phosphorylation of the voltage-gated Ca2+ channels, causing them to spend more time in the open state.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      18.9
      Seconds

  • Question 3 - Which of the following pairs are correct concerning arteriolar tone? ...

    Incorrect

    • Which of the following pairs are correct concerning arteriolar tone?

      Your Answer: Neural control: vasoconstriction activated by sympathetic nerves

      Correct Answer: Hormonal control: catecholamines affect the adrenergic receptors of the vascular smooth muscle

      Explanation:

      Catecholamines released from the adrenal medulla act on the noradrenergic receptors of the vascular smooth muscles. In the skeletal muscles and liver it causes vasodilation whilst it causes vasoconstriction in the rest of the blood vessels of the body.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      65.7
      Seconds

  • Question 4 - Which is the most common site for primary cardiac tumours to occur in...

    Incorrect

    • Which is the most common site for primary cardiac tumours to occur in adults?

      Your Answer: Left ventricle

      Correct Answer: Left atrium

      Explanation:

      Myxomas are the most common type of primary heart tumour. The tumour is derived from multipotential mesenchymal cells and may cause a ball valve-type obstruction. About 75% of myxomas occur in the left atrium of the heart, usually beginning in the wall that divides the two upper chambers of the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      24.4
      Seconds

  • Question 5 - Myocardial fibers have a resting membrane potential of approximately: ...

    Correct

    • Myocardial fibers have a resting membrane potential of approximately:

      Your 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
      10.3
      Seconds

  • Question 6 - Nitric oxide triggers vascular smooth muscle contraction through activation of which enzyme? ...

    Correct

    • Nitric oxide triggers vascular smooth muscle contraction through activation of which enzyme?

      Your Answer: Guanylyl cyclase

      Explanation:

      Impaired production or excess catabolism of NO impairs this endothelium-dependent vasodilator function and may contribute to excessive vasoconstriction under various pathological situations.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      10.3
      Seconds

  • Question 7 - 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
      22.9
      Seconds

  • Question 8 - 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
      18.8
      Seconds

  • Question 9 - Concerning S3, which of the following statements is INCORRECT? ...

    Incorrect

    • Concerning S3, which of the following statements is INCORRECT?

      Your Answer: Occurs during ventricular rapid filling phase

      Correct Answer: Coincide with atrial contraction

      Explanation:

      A third heart sound also called a ventricular gallop occurs at the beginning of diastole after S2 and is lower in pitch than S1 or S2 as it is not of valvular origin. The third heart sound is benign in youth, some trained athletes, and sometimes in pregnancy but if it re-emerges later in life it may signal cardiac problems, such as a failing left ventricle as in dilated congestive heart failure (CHF). S3 is thought to be caused by the oscillation of blood back and forth between the walls of the ventricles initiated by blood rushing in from the atria. The reason the third heart sound does not occur until the middle third of diastole is probably that during the early part of diastole, the ventricles are not filled sufficiently to create enough tension for reverberation. It may also be a result of tensing of the chordae tendineae during rapid filling and expansion of the ventricle. In other words, an S3 heart sound indicates increased volume of blood within the ventricle. An S3 heart sound is best heard with the bell-side of the stethoscope (used for lower frequency sounds). A left-sided S3 is best heard in the left lateral decubitus position and at the apex of the heart, which is normally located in the 5th left intercostal space at the midclavicular line. A right-sided S3 is best heard at the lower-left sternal border. The way to distinguish between a left and right-sided S3 is to observe whether it increases in intensity with inhalation or exhalation. A right-sided S3 will increase on inhalation, while a left-sided S3 will increase on exhalation.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      72.2
      Seconds

  • Question 10 - Activation of baroreceptor reflex involves: ...

    Incorrect

    • Activation of baroreceptor reflex involves:

      Your Answer: Increase in heart rate base of inhibition of the vagal cardiac motor neurons

      Correct Answer: Short term regulation of systemic blood pressure

      Explanation:

      Baroreceptors are found in the heart and the blood vessels. They are the carotid sinus and the aortic arch receptors and respond to the minute to minute change in the blood pressure i.e. a change in the pulsatile pressure and not to a change in the mean arterial pressure. If the pulse pressure decreases, the rate of firing of the receptors decreases, stimulating an increase in the heart rate and blood pressure. Mechanisms that regulate the long term blood pressure control include the renin-angiotensin-aldosterone mechanism.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      31.7
      Seconds

  • Question 11 - 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
      32.9
      Seconds

  • Question 12 - In ventricular fibrillation (VF), the first defibrillation attempt (with a biphasic defibrillator) should...

    Incorrect

    • In ventricular fibrillation (VF), the first defibrillation attempt (with a biphasic defibrillator) should be made at:

      Your Answer: 360 J

      Correct Answer: 200 J

      Explanation:

      Defibrillation is a common treatment for life-threatening cardiac dysrhythmias and ventricular fibrillation. If the patient is in Ventricular tachycardia (VT) or ventricular fibrillation (VF) on the monitor, immediately apply the pads and shock the patient with 120-200 Joules on a biphasic defibrillator or 360 Joules on a monophasic defibrillator.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      17.5
      Seconds

  • Question 13 - 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
      28.1
      Seconds

  • Question 14 - Coronary arteries fill up during ...

    Correct

    • Coronary arteries fill up during

      Your Answer: Diastole

      Explanation:

      During contraction of the ventricular myocardium (systole), the subendocardial coronary vessels (the vessels that enter the myocardium) are compressed due to the high ventricular pressures. This compression results in momentary retrograde blood flow (i.e., blood flows backward toward the aorta) which further inhibits perfusion of myocardium during systole. However, the epicardial coronary vessels (the vessels that run along the outer surface of the heart) remain open. Because of this, blood flow in the sub endocardium stops during ventricular contraction. As a result, most myocardial perfusion occurs during heart relaxation (diastole) when the subendocardial coronary vessels are open and under lower pressure.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      9.2
      Seconds

  • Question 15 - Myocyte action potentials – Choose the false statement: ...

    Correct

    • Myocyte action potentials – Choose the false statement:

      Your 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
      45.5
      Seconds

  • Question 16 - The average end diastolic volume in a healthy individual’s ventricle is? ...

    Incorrect

    • The average end diastolic volume in a healthy individual’s ventricle is?

      Your Answer: 180 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
      12.5
      Seconds

  • Question 17 - 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
      24.1
      Seconds

  • Question 18 - 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
      6.4
      Seconds

  • Question 19 - Cross-bridges between actin and myosin filaments contain: ...

    Incorrect

    • Cross-bridges between actin and myosin filaments contain:

      Your Answer: Tropomyosin

      Correct Answer: Calcium ions

      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 causes 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
      23.5
      Seconds

  • Question 20 - 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
      40.7
      Seconds

  • Question 21 - 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: Atrial systole

      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
      31.1
      Seconds

  • Question 22 - 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: Exposure of actin binding site for myosin

      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
      48.6
      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
      12
      Seconds

  • Question 24 - The Sinoatrial node in the majority of people is supplied by the? ...

    Correct

    • The Sinoatrial node in the majority of people is supplied by the?

      Your Answer: Right coronary artery

      Explanation:

      In 60% of people, the SA node is supplied by the right coronary artery branch and in 40% of the people by the left coronary artery.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.2
      Seconds

  • Question 25 - In which organ will you find extremely porous sinusoidal capillaries, with discontinuous endothelium?...

    Correct

    • In which organ will you find extremely porous sinusoidal capillaries, with discontinuous endothelium?

      Your Answer: Liver

      Explanation:

      The liver is the organ which contains sinusoidal capillaries with discontinuous endothelium. The brain, lungs and the intestine all contain continuous capillaries, however the kidney contains fenestrated capillaries to aid in filtration.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      21.3
      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
      19.8
      Seconds

  • Question 27 - 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
      31.5
      Seconds

  • Question 28 - 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
      18.2
      Seconds

  • Question 29 - 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
      21
      Seconds

  • Question 30 - Which of the following is true with AV nodal delay? ...

    Correct

    • Which of the following is true with AV nodal delay?

      Your Answer: Shortened by sympathetic stimulation

      Explanation:

      AV nodal delay Is about 0.1s before the action potential spreads to the ventricles. It is shortened by stimulation of the sympathetic nervous system and lengthened by stimulation of the parasympathetic system.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      18
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

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