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  • Question 1 - In the Fick‘s method of measuring cardiac output, the arterial oxygen content can...

    Incorrect

    • In the Fick‘s method of measuring cardiac output, the arterial oxygen content can be measured in a sample obtained from

      Your Answer: The aorta

      Correct Answer: The pulmonary vein

      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.Note that (Ca – Cv) is also known as the arteriovenous oxygen difference.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      21.9
      Seconds

  • Question 2 - Which vaso metabolite decreases coronary blood flow? ...

    Incorrect

    • Which vaso metabolite decreases coronary blood flow?

      Your Answer: Co2

      Correct Answer: Endothelin

      Explanation:

      Decreased O2, increased CO2, lactate, prostaglandins, adenine nucleotides, adenosine, H+, K+ and cyanide produce vasodilation and thus an increase in coronary blood flow.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.8
      Seconds

  • Question 3 - The rate of depolarization of the SA node membrane potential is modulated by...

    Correct

    • The rate of depolarization of the SA node membrane potential is modulated by the following:

      Your Answer: All of the above

      Explanation:

      Rate of depolarization of the SA node is modulated by all of these.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      10.3
      Seconds

  • Question 4 - 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
      12.9
      Seconds

  • Question 5 - Calcium is mobilized from the sarcoplasmic reticulum through: ...

    Correct

    • Calcium is mobilized from the sarcoplasmic reticulum through:

      Your Answer: Ryanodine receptor (RyR2) calcium release channels

      Explanation:

      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. As a result intracellular calcium increases binding to troponin C resulting in contraction.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      5.4
      Seconds

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

    Incorrect

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

      Your Answer: Ventricles are relaxed

      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
      18.3
      Seconds

  • Question 7 - The coronary sinus drains into the: ...

    Correct

    • The coronary sinus drains into the:

      Your 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
      5.4
      Seconds

  • Question 8 - The most resistant area in the brain to hypoxia is: ...

    Correct

    • The most resistant area in the brain to hypoxia is:

      Your Answer: Brain stem

      Explanation:

      The structures in the brainstem are more resistant to hypoxia than the cerebral cortex and the rest of the brain structures.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      5.3
      Seconds

  • Question 9 - In Starling’s law of the heart, the decrease in tension developed by muscle...

    Incorrect

    • In Starling’s law of the heart, the decrease in tension developed by muscle contraction at high degrees of stretch is due to:

      Your Answer: Leak of calcium from cell membranes of overstretched cardiac muscle

      Correct Answer: Disruption of myocardial fibers

      Explanation:

      Starling law states that the force of contraction is directly proportional to the preload. When the heart muscle is stretched beyond its limit the tension that is developed decreases, this is not due to loss of formation of effective myosin and actin cross bridges. The heart muscles despite being fully stretched is never stretched to this point. The reason for this decreased tension is physical disruption of the myocardial fibers.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      14.4
      Seconds

  • Question 10 - 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
      4.5
      Seconds

  • Question 11 - What is cardiac output? ...

    Correct

    • What is cardiac output?

      Your Answer: Product of stroke volume and heart rate

      Explanation:

      Cardiac output is the product of stroke volume and heart rate.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      5.8
      Seconds

  • Question 12 - 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
      10.9
      Seconds

  • Question 13 - Which of the following intercellular connections is important in endothelial barrier function? ...

    Correct

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

      Your 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
      14.5
      Seconds

  • Question 14 - Which of the following supplies the AV node? ...

    Correct

    • Which of the following supplies the AV node?

      Your Answer: Right coronary artery

      Explanation:

      The AV node is supplied by the right coronary artery near the origin of the posterior IV artery.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      52.7
      Seconds

  • Question 15 - The bradycardia that occurs in patients with raised intracranial pressure is a result...

    Correct

    • The bradycardia that occurs in patients with raised intracranial pressure is a result of the?

      Your Answer: Cushing reflex

      Explanation:

      When intracranial pressure is increased, the blood supply to RVLM neurons is compromised. This results in an increase in their discharge as a result of hypoxia and hypercapnia. The resultant rise in systemic arterial pressure (Cushing reflex) tends to restore the blood flow to the medulla.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      5.3
      Seconds

  • Question 16 - Select the correct statement regarding the 4th heart sound, it? ...

    Incorrect

    • Select the correct statement regarding the 4th heart sound, it?

      Your Answer: Coincides with rapid ventricular filling.

      Correct Answer: Can be heard in atrial systole.

      Explanation:

      The fourth heart sound is not normally audible in a normal adult. It occurs as a consequence of ventricular hypertrophy. It is caused by filling of the ventricle by atrial systole.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      9
      Seconds

  • Question 17 - 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: It decreases heart rate via the SA node

      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
      38.6
      Seconds

  • Question 18 - Which is the commonest cardiovascular abnormality seen in an adult patient with Marfan’s...

    Incorrect

    • Which is the commonest cardiovascular abnormality seen in an adult patient with Marfan’s syndrome?

      Your Answer: Aortic dissection

      Correct Answer: Aortic aneurysm

      Explanation:

      Marfan syndrome (MFS) is a genetic disorder of connective tissue. The degree to which people are affected varies. People with Marfan’s tend to be tall, and thin, with long arms, legs, fingers and toes. They also typically have flexible joints and scoliosis. The most serious complications involve the heart and aorta with an increased risk of mitral valve prolapse and aortic aneurysm.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      3.7
      Seconds

  • Question 19 - Arterioles stemming from the coronary artery can also empty into the heart directly...

    Correct

    • Arterioles stemming from the coronary artery can also empty into the heart directly via the:

      Your Answer: Arteriosinusoidal vessels

      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. They include arteriosinusoidal vessels, which connect the arterioles to the heart chambers. The thebesian veins drain the capillaries into the chambers and the arterioluminal vessels drain small arteries directly into the chambers.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      12.8
      Seconds

  • Question 20 - The amount of a substance taken up by an organ (or whole body)...

    Correct

    • 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 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
      11.3
      Seconds

  • Question 21 - Xanthines such as caffeine and theophylline are positively inotropic due to: ...

    Incorrect

    • Xanthines such as caffeine and theophylline are positively inotropic due to:

      Your Answer: Circulating catecholamines

      Correct 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
      10.1
      Seconds

  • Question 22 - Tunica intima is made up of? ...

    Incorrect

    • Tunica intima is made up of?

      Your Answer: 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
      5
      Seconds

  • Question 23 - 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: Right atrium

      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
      11.3
      Seconds

  • Question 24 - Where does the SA node develop? ...

    Correct

    • Where does the SA node develop?

      Your Answer: From structures on the right side of the embryo.

      Explanation:

      The SA node develops from the right side of the embryo and the AV node from the left. This is the reason why in adults the right vagus supplies the SA node and the left vagus supplies the AV node.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      14.3
      Seconds

  • Question 25 - Which factor produced by the endothelium is responsible for the regulation of vascular...

    Correct

    • Which factor produced by the endothelium is responsible for the regulation of vascular cell growth?

      Your Answer: Vascular endothelial growth factor (VEGF)

      Explanation:

      VEGF is produced by the endothelial cells and is the major growth factor responsible for causing vasculogenesis. Some isoforms of this growth factor also have a prominent role in formation of lymphatic vessels.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      7.4
      Seconds

  • Question 26 - The basic unit of contraction in myocytes is: ...

    Correct

    • The basic unit of contraction in myocytes is:

      Your Answer: Sarcomere

      Explanation:

      Sarcomere is the organelle where calcium is stored to be released during contraction of the muscle. It is the basic unit of contraction in striated muscle fibers. As myocytes are also striated muscles, sarcomeres also forms the basic unit of contraction. The impulses travel along the membrane and via its interaction with the dihydropyridine receptors it releases the stored calcium.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      3.8
      Seconds

  • Question 27 - Depolarization of the T tubule membrane activates the sarcoplasmic reticulum via which receptors?...

    Correct

    • Depolarization of the T tubule membrane activates the sarcoplasmic reticulum via which receptors?

      Your 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
      5.4
      Seconds

  • Question 28 - Which of the following does not lower ventricular rate in atrial fibrillation? ...

    Correct

    • Which of the following does not lower ventricular rate in atrial fibrillation?

      Your Answer: Adrenaline

      Explanation:

      Adrenaline is a sympathetic neurotransmitter which increases the heart rate. During atrial fibrillation the atria is contracting at more than 200 beats/min. Acetylcholine is a parasympathetic neurotransmitter decreasing the heart rate. Digital also depresses the conduction at the AV conduction. Vagal discharge and occulocardiac reflux decrease the heart rate and convert the tachycardia into normal sinus rhythm.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      6.8
      Seconds

  • Question 29 - Which of the following is NOT associated with the development of aortic regurgitation?...

    Correct

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

      Your 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
      137.5
      Seconds

  • Question 30 - 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
      22.2
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (20/30) 67%
Medicine (20/30) 67%
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