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  • Question 1 - In which organ will you find extremely porous sinusoidal capillaries, with discontinuous endothelium?...

    Incorrect

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

      Your Answer: Lungs

      Correct 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
      21.8
      Seconds

  • Question 2 - The coronary sinus, which empties into the right atrium, serves to? ...

    Incorrect

    • The coronary sinus, which empties into the right atrium, serves to?

      Your Answer: Supply the posterior ventricular wall

      Correct Answer: Drain the venous supply of the myocardium

      Explanation:

      The coronary sinus is a collection of veins joined together to form a large vessel that collects blood from the heart muscle (myocardium). It delivers deoxygenated blood to the right atrium, as do the superior and inferior vena cava.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      32.4
      Seconds

  • Question 3 - Which of the following structures of the cardiac conduction system is located in...

    Incorrect

    • Which of the following structures of the cardiac conduction system is located in the right posterior portion of the interatrial septum?

      Your Answer: Purkinje system

      Correct Answer: AV node

      Explanation:

      AV node is located at the right posterior portion of the interatrial septum.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      52.7
      Seconds

  • Question 4 - What is the function of the BK channel on the vascular smooth muscle...

    Correct

    • What is the function of the BK channel on the vascular smooth muscle membrane?

      Your Answer: Massive K+ efflux, increasing membrane potential, and shutting off the voltage gated Ca2+ channel

      Explanation:

      BK channels, also known as large-conductance calcium-activated potassium channels, play a critical role in regulating vascular smooth muscle tone. When BK channels open, they allow a large efflux of potassium ions (K+) out of the cell. This efflux of K+ causes the membrane potential to become more negative (hyperpolarization), which in turn leads to the closure of voltage-gated calcium channels. The closure of these calcium channels reduces the influx of calcium ions (Ca2+) into the smooth muscle cells, resulting in decreased intracellular calcium levels and subsequent relaxation of the smooth muscle.

      Thus, BK channels promote smooth muscle relaxation by hyperpolarizing the membrane and reducing the activity of voltage-gated Ca2+ channels.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      32
      Seconds

  • Question 5 - 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
      25.9
      Seconds

  • Question 6 - Concerning S3, which of the following statements is INCORRECT? ...

    Incorrect

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

      Your Answer: AV valves are open

      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
      22.6
      Seconds

  • Question 7 - How many molecules of myosin attach to actin at any given time? ...

    Incorrect

    • How many molecules of myosin attach to actin at any given time?

      Your Answer: 4

      Correct Answer: 1

      Explanation:

      1 molecule of myosin binds to actin at any give time.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      11.1
      Seconds

  • Question 8 - Which of the following affects the magnitude of the action potential? ...

    Incorrect

    • Which of the following affects the magnitude of the action potential?

      Your Answer: Extracellular Na+/K+ ratio

      Correct Answer: Changes in the external Na+ concentration

      Explanation:

      The magnitude of the action potential is determined by the sodium current. Increase in external sodium will result in increased influx of sodium and hence generation of a stronger action potential.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      24.9
      Seconds

  • Question 9 - 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: NYHA Class III

      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
      25.8
      Seconds

  • Question 10 - 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
      7
      Seconds

  • Question 11 - Stimulation of the carotid sinus results in: ...

    Correct

    • Stimulation of the carotid sinus results in:

      Your Answer: Drop in blood pressure

      Explanation:

      Stimulation of the carotid sinus will result in an increase in the baroreceptor discharge. This will travel via the afferent nerves to the medulla. Signals will pass through the vagus nerve to decrease the sympathetic outflow to the heart and the blood vessels. This inhibition will result in vasodilation of the blood vessels, venodilation and bradycardia hence decreasing the total peripheral resistance and lowering the blood pressure.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      11.2
      Seconds

  • Question 12 - 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 Poiseuille – Hagen 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
      43.2
      Seconds

  • Question 13 - Regarding the length of systole and diastole which of the following is true?...

    Incorrect

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

      Your Answer: Cardiac muscle can be tetanise

      Correct 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
      49.7
      Seconds

  • Question 14 - Coronary blood flow occurs in? ...

    Correct

    • Coronary blood flow occurs in?

      Your Answer: Diastole

      Explanation:

      Coronary arteries are unique in that they fill during diastole, when not occluded by valve cusps nor compressed by myocardial contraction).

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      220.1
      Seconds

  • Question 15 - 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
      28.2
      Seconds

  • Question 16 - When looking at the JVP what does the c wave signify: ...

    Correct

    • When looking at the JVP what does the c wave signify:

      Your Answer: Isovolumetric ventricular contraction

      Explanation:

      The C wave signifies a rise in the atrial pressure during isovolumetric contraction due to the tricuspid valve bulging into the atria.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      19.7
      Seconds

  • Question 17 - Tunica intima is made up of? ...

    Correct

    • Tunica intima is made up of?

      Your 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
      14.5
      Seconds

  • Question 18 - Where on the surface of the chest is the normal site of auscultation...

    Incorrect

    • Where on the surface of the chest is the normal site of auscultation for the mitral area?

      Your Answer: 5th intercostal space in the left lower sternal border

      Correct Answer: 4th left intercostal space in the mid-clavicular line

      Explanation:

      The mitral valve is situated in the left 4th intercostal space just beneath the sternum, in the mid clavicular line.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      196.8
      Seconds

  • Question 19 - Which of the following intercellular connections is important in endothelial barrier function? ...

    Incorrect

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

      Your Answer: Desmosomes

      Correct 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
      30.7
      Seconds

  • Question 20 - 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: 50/ 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
      88.5
      Seconds

  • Question 21 - Which part of the ECG represents ventricular repolarisation? ...

    Correct

    • Which part of the ECG represents ventricular repolarisation?

      Your Answer: T wave

      Explanation:

      Ventricular repolarisation is denoted by the T wave.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      19
      Seconds

  • Question 22 - 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: Calcium channels

      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
      12.4
      Seconds

  • Question 23 - 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: Right atrium

      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
      24.1
      Seconds

  • Question 24 - Which of the following is true of the Natriuretic hormones? ...

    Incorrect

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

      Your Answer: ANP acts only in a paracrine fashion

      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
      1.1
      Seconds

  • Question 25 - The heart rate can be accelerated by: ...

    Correct

    • The heart rate can be accelerated by:

      Your Answer: Exercise and thyroid hormones

      Explanation:

      The firing of the SA node will increase due to exercises and as the thyroid hormone has a chronotropic effect on the heart, it too will result in an increase in the heart rate via stimulation of the adrenergic receptors of the heart. As during exercise the sympathetic nervous system is activated, it will directly have an positive chronotropic effect on the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      18.4
      Seconds

  • Question 26 - Which of the following factors serve to decrease cardiac output? ...

    Correct

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

      Your 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
      33.6
      Seconds

  • Question 27 - Cholinergic nerves from the vagus innervate the SA and AV nodes via which...

    Incorrect

    • Cholinergic nerves from the vagus innervate the SA and AV nodes via which receptor in the heart?

      Your Answer: B1 receptor

      Correct Answer: M2 receptor

      Explanation:

      M2 receptor is found in the heart. M3 and M4 are associated with smooth muscle.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      63.7
      Seconds

  • Question 28 - Which of the following components regulate cardiac output? ...

    Correct

    • Which of the following components regulate cardiac output?

      Your Answer: All of the above

      Explanation:

      Cardiac output is regulated by the autonomic nervous system with sympathetic nerves having a positive chronotropic and inotropic effect and parasympathetic nerves having the opposite effect. An increase in preload will increase cardiac output likewise an afterload increase will also increase cardiac output.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      25.4
      Seconds

  • Question 29 - 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
      66.7
      Seconds

  • Question 30 - 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
      16.8
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (12/30) 40%
Medicine (12/30) 40%
Passmed
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