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  • Question 1 - 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
      11.7
      Seconds

  • Question 2 - Which of the following is NOT associated with the development of aortic regurgitation?...

    Incorrect

    • Which of the following is NOT associated with the development of aortic regurgitation?

      Your Answer: Bechet's disease

      Correct Answer: Dilated cardiomyopathy

      Explanation:

      Aortic insufficiency, is often due to the aortic root dilation, which is idiopathic in over 80% of cases, but otherwise may result from aging, syphilitic aortitis, osteogenesis imperfecta, aortic dissection, Bechet’s disease, reactive arthritis and systemic hypertension. Additionally, aortic insufficiency has been linked to the use of some medications and other potential causes that affect the valve directly including Marfan’s syndrome, Ehlers–Danlos syndrome, ankylosing spondylitis, and systemic lupus erythematosus. In acute cases of aortic insufficiency, the main causes are infective endocarditis, aortic dissection or trauma. Dilated cardiomyopathy is associated with the development of mitral regurgitation, not aortic regurgitation

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      22.3
      Seconds

  • Question 3 - Direct conduction from the atrium to the ventricles is prevented by: ...

    Incorrect

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

      Your Answer: Bundle of his

      Correct 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
      21.8
      Seconds

  • Question 4 - 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
      11.5
      Seconds

  • Question 5 - 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
      35.6
      Seconds

  • Question 6 - Preload: ...

    Correct

    • Preload:

      Your Answer: Is the degree to which the myocardium is stretched before is contracts

      Explanation:

      Preload is end diastolic volume. It is the degree to which the heart muscle fiber is stretched when it fills up completely just before the heart contracts.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      10.8
      Seconds

  • Question 7 - Which of the following regulates the calcium release channels? ...

    Incorrect

    • Which of the following regulates the calcium release channels?

      Your Answer: Troponin c

      Correct Answer: Calstabin 2

      Explanation:

      Ca2+ is released from the SR through a Ca2+ release channel, a cardiac isoform of the ryanodine receptor (RyR2), which controls intracytoplasmic [Ca2+] and, as in vascular smooth-muscle cells, leads to the local changes in intracellular [Ca2+] called calcium sparks. A number of regulatory proteins, including calstabin 2, inhibit RyR2 and, thereby, the release of Ca2+ from the SR.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      13.4
      Seconds

  • Question 8 - What is troponin? ...

    Incorrect

    • What is troponin?

      Your Answer: A component of thick filaments

      Correct Answer: A component of thin filaments

      Explanation:

      Skeletal muscle cytoplasmic proteins include myosin and actin (also known as thick and thin filaments, respectively) which are arranged in a repeating unit called a sarcomere. Troponin is a component of thin filaments (along with tropomyosin), and is the protein to which calcium binds.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      37.1
      Seconds

  • Question 9 - In ventricular fibrillation (VF), the first defibrillation attempt (with a biphasic defibrillator) should...

    Correct

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

      Your 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
      7.3
      Seconds

  • Question 10 - Myocardial contractility is improved by: ...

    Correct

    • Myocardial contractility is improved by:

      Your Answer: Caffeine

      Explanation:

      Caffeine and other theophyllines breakdown cAMP and have a positive ionotropic effect on the heart. Drugs like quinidine, procainamide and conditions like hypoxia and hypercapnia decreases the contractility of the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      16.6
      Seconds

  • Question 11 - The function of ATP in cardiac muscle contraction includes: ...

    Incorrect

    • The function of ATP in cardiac muscle contraction includes:

      Your Answer: Transmission of contractile force from one cell to the next

      Correct Answer: Binding to myosin after the power stroke to allow uncoupling of actin and myosin

      Explanation:

      After calcium binds to the troponin C, there is a conformational change in the structure of troponin I and tropomyosin, which moves out of the way and frees the site where myosin can bind to actin. This results in the formation of the cross linkage of the actin and myosin giving rise to the power stroke in the contraction phase. This occurs with the release of ADP. When ATP combines to this complex it breaks and the cycle repeats itself.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      246.1
      Seconds

  • Question 12 - Which of the following factors serve to decrease cardiac output? ...

    Incorrect

    • Which of the following factors serve to decrease cardiac output?

      Your Answer: Pregnancy

      Correct Answer: Standing from a lying position

      Explanation:

      Sleep has no effect on the cardiac output. Anxiety, excitement, increased body temperature 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
      45.3
      Seconds

  • Question 13 - The following is true of the sinus node: ...

    Correct

    • The following is true of the sinus node:

      Your Answer: It generates impulses automatically & at a quicker rate than other cardiac cells

      Explanation:

      The SA node exhibits automaticity. It generates the impulses to which the heart beats. It fires at a faster speed than the rest of the nervous components of the heart i.e. the AV nodes, purkinje fibers. This is the reason when the SA node fails the heart beats to the rhythm of the AV node.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      26.9
      Seconds

  • Question 14 - AV valves open during? ...

    Incorrect

    • AV valves open during?

      Your Answer: Systole

      Correct Answer: Early diastole

      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.The first stage, diastole, 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. The second stage, atrial systole, is when the atrium contracts, and blood flows from atrium to the ventricle.The third stage, isovolumic contraction is when the ventricles begin to contract, the AV and semilunar valves close, and there is no change in volume. The fourth stage, ventricular ejection, is when the ventricles are contracting and emptying, and the semilunar valves are open. During the fifth 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
      7.7
      Seconds

  • Question 15 - Which of the following is NOT true of the parasympathetic control of the...

    Incorrect

    • Which of the following is NOT true of the parasympathetic control of the heart?

      Your Answer:

      Correct Answer: It can be blocked by beta blockers

      Explanation:

      Parasympathetic fibers do not innervate the Beta receptors on the heart. They are innervated by the sympathetic nerve fibers. Then a beta blocker such as propranolol will block the sympathetic outflow and increase the parasympathetic tone of the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 16 - Which of the following is true of the Natriuretic hormones? ...

    Incorrect

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

      Your Answer:

      Correct Answer: They are released in response to hypervolemia

      Explanation:

      Natriuretic hormones are vasodilators released in response to hypervolemia.

      Natriuretic hormones (NH) include three groups of compounds: the natriuretic peptides NPs (ANP, BNP and CNP), the gastrointestinal peptides (guanylin and uroguanylin), and endogenous cardiac steroids. These substances induce the kidney to excrete sodium and therefore participate in the regulation of sodium and water homeostasis, blood volume, and blood pressure (BP). In addition to their peripheral functions, these hormones act as neurotransmitters or neuromodulators in the brain.

      Atrial natriuretic peptide (ANP) plays a crucial role in blood pressure regulation by inducing natriuresis and diuresis in the kidney, inhibiting renin secretion, aldosterone production, and promoting vasorelaxation.  Two paracrine factors derived from endothelial cells play important roles in modulating ANP secretion. Endothelin, a potent vasoconstrictor, stimulates ANP secretion and augments stretch induced ANP secretion. The dramatic increase in ANP release produced by cardiac ischemia appears to be mediated in part by endothelin. Nitric oxide (NO), an important vasodilator, is also produced by endothelial cells and inhibits ANP secretion.

      Brain natriuretic peptide (BNP) shares ANP’s receptor but is primarily associated with antifibrotic effects in ventricular remodeling, serving as a biomarker for heart failure and myocardial infarction.

      C-type natriuretic peptide (CNP) acts locally in an autocrine/paracrine manner, exerting potent cardiovascular effects, including vasorelaxation and vascular remodeling post-injury. NPs also demonstrate diverse effects beyond cardiovascular and renal systems, such as bronchodilation, anti-inflammatory actions, and metabolic effects on adipose tissue and long bones.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 17 - The direct determinants of cardiac output are ...

    Incorrect

    • The direct determinants of cardiac output are

      Your Answer:

      Correct Answer: Stroke volume and heart rate

      Explanation:

      Cardiac output is classically defined alongside stroke volume (SV) and the heart rate (HR) as:Cardiac Output [L/min] = Stroke Volume [L/beat] x Heart Rate [beats/min]

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 18 - Which vagus nerve mainly supplies the AV node? ...

    Incorrect

    • Which vagus nerve mainly supplies the AV node?

      Your Answer:

      Correct Answer: Left vagus

      Explanation:

      As the AV node develops from the left side of the embryo It is supplied by the left vagus nerve.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 19 - Coronary flow is reduced during ...

    Incorrect

    • Coronary flow is reduced during

      Your Answer:

      Correct Answer: Tachycardia

      Explanation:

      Maximum amount of blood flow in the coronary arteries occur during diastole. When the heart rate increases which is also called tachycardia the duration of diastole decreases. Hence the amount of blood flow to the cardiac muscle also decreases.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 20 - Coronary arteries fill up during ...

    Incorrect

    • Coronary arteries fill up during

      Your Answer:

      Correct 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
      0
      Seconds

  • Question 21 - Which heart sounds are matched correctly? ...

    Incorrect

    • Which heart sounds are matched correctly?

      Your Answer:

      Correct Answer: All of the above

      Explanation:

      In healthy adults, there are two normal heart sounds often described as a lub and a dub (or dup), that occur in sequence with each heartbeat. These are the first heart sound (S1) and second heart sound (S2), produced by the closing of the atrioventricular valves and semilunar valves, respectively. In addition to these normal sounds, a variety of other sounds may be present including heart murmurs, adventitious sounds, and gallop rhythms S3 and S4. 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. S4 when audible in an adult is called a presystolic gallop or atrial gallop. This gallop is produced by the sound of blood being forced into a stiff or hypertrophic ventricle.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 22 - When observing a JVP, which of the following would lead to prominent v...

    Incorrect

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

      Your Answer:

      Correct 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
      0
      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:

      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
      0
      Seconds

  • Question 24 - Which of the following conditions does not influence the cardiac output? ...

    Incorrect

    • Which of the following conditions does not influence the cardiac output?

      Your Answer:

      Correct Answer: Sleep

      Explanation:

      Sleep has no effect on the cardiac output.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 25 - Currents caused by opening of which of the following channels contribute to the...

    Incorrect

    • 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:

      Correct 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
      0
      Seconds

  • Question 26 - Most of the venous blood returns to the heart through the: ...

    Incorrect

    • Most of the venous blood returns to the heart through the:

      Your Answer:

      Correct Answer: Coronary sinus and anterior cardiac veins

      Explanation:

      Most of the venous blood returns to the heart via the coronary sinus and the anterior cardiac veins which drain into the right atrium.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 27 - Which of the following best describes the cardiac muscle? ...

    Incorrect

    • Which of the following best describes the cardiac muscle?

      Your Answer:

      Correct 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
      0
      Seconds

  • Question 28 - Afferent fibers from the baroreceptors of the great arteries form branches of which...

    Incorrect

    • Afferent fibers from the baroreceptors of the great arteries form branches of which cranial nerves?

      Your Answer:

      Correct Answer: Glossopharyngeal and vagus nerves

      Explanation:

      The receptors of the carotid sinus are innervated by the carotid sinus nerve, a branch of the glossopharyngeal nerve. The aortic arch receptors located in the arch of the aorta are innervated by the aortic depressor nerve, a branch of the vagus nerve.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 29 - Heart rate can be slowed by: ...

    Incorrect

    • Heart rate can be slowed by:

      Your Answer:

      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
      0
      Seconds

  • Question 30 - A 55 year old cardiac patient is comfortable at rest but heavy housework...

    Incorrect

    • A 55 year old cardiac patient is comfortable at rest but heavy housework results in fatigue, palpitations or dyspnoea. What New York Heart Association class best describes the severity of their disease?

      Your Answer:

      Correct Answer: NYHA Class II

      Explanation:

      New York Heart Association functional classification:

      Class I: no limitation is experienced in any activities; there are no symptoms from ordinary activities.

      Class II: slight, mild limitation of activity; the patient is comfortable at rest or with mild exertion.

      Class III: marked limitation of any activity; the patient is comfortable only at rest.

      Class IV: any physical activity brings on discomfort and symptoms occur at rest.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (7/14) 50%
Medicine (7/14) 50%
Passmed
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