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  • Question 1 - The rate of depolarisation of the sinus node membrane potential is modulated by...

    Correct

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

      Your 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
      11.3
      Seconds

  • Question 2 - The predominant receptors in the hearts conduction system are? ...

    Incorrect

    • The predominant receptors in the hearts conduction system are?

      Your Answer: Both β1 and β2

      Correct Answer: Î’1

      Explanation:

      All of the components of the intrinsic conduction system contain autorhythmic cells that spontaneously depolarize. In the absence of extrinsic neural or hormonal influences, the SA node pacing rate would be about 100 beats per minute (bpm). The heart rate and cardiac output, however, must vary in response to the needs of the body’s cells for oxygen and nutrients under varying conditions. In order to respond rapidly to changing requirements of the body’s tissues, the heart rate and contractility are regulated by the autonomic nervous system (ANS), hormones, and other factors. The ANS has two interacting systems: the sympathetic and parasympathetic systems.

      Sympathetic receptors: There are two types of adrenergic receptors: β and α. In the cardiovascular system there are β1, β2, α1, and α2 adrenergic receptors. β1 adrenergic receptors are expressed in the heart conduction system (in the SA node, AV node, and on atrial and ventricular cardiomyocytes). The activation of β1 receptors increases heart rate (via the SA node), and contractility.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      7.3
      Seconds

  • Question 3 - Vasodilatation in skeletal muscle can be caused by: ...

    Incorrect

    • Vasodilatation in skeletal muscle can be caused by:

      Your Answer: Endothelin-1

      Correct Answer: Sympathetic cholinergic nerves

      Explanation:

      In skeletal muscles some fibers that cause vasodilation run with the nerves of the sympathetic system but are cholinergic in nature. These nerves are not active during rest but become active during exercise and stress.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      23.8
      Seconds

  • Question 4 - Calcium induced calcium release occurs in the sarcoplasmic reticulum by activation of which...

    Correct

    • Calcium induced calcium release occurs in the sarcoplasmic reticulum by activation of which receptors

      Your Answer: Ryanodine receptors

      Explanation:

      Calcium-induced calcium release (CICR) describes a biological process whereby calcium is able to activate calcium release from intracellular Ca2+ stores (e.g., endoplasmic reticulum or sarcoplasmic reticulum). CICR occurs when the resulting Ca2+ influx activates ryanodine receptors on the SR membrane, which causes more Ca2+ to be released into the cytosol.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      14
      Seconds

  • Question 5 - 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
      6.7
      Seconds

  • Question 6 - The direct determinants of cardiac output are ...

    Correct

    • The direct determinants of cardiac output are

      Your 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
      24.7
      Seconds

  • Question 7 - Regarding the cardiac muscle striations as viewed under the microscope, which areas are...

    Correct

    • Regarding the cardiac muscle striations as viewed under the microscope, which areas are dark?

      Your Answer: A band and z line

      Explanation:

      Dark bands: a, h. Dark line: z. Clear band: i, m

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      35.2
      Seconds

  • Question 8 - Why does arterial blood pressure drop during pregnancy? ...

    Incorrect

    • Why does arterial blood pressure drop during pregnancy?

      Your Answer: Oestrogen relaxes vascular smooth muscle

      Correct 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
      32.5
      Seconds

  • Question 9 - Where on the surface of the chest is the normal site of auscultation...

    Correct

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

      Your 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
      39.4
      Seconds

  • Question 10 - Catecholamines… ...

    Correct

    • Catecholamines…

      Your Answer: Activate adenylyl cyclase

      Explanation:

      Norepinephrine and epinephrine activate or deactivate adenylyl cyclase resulting in a decrease or an increase in the production of cAMP.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      17.3
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (7/10) 70%
Medicine (7/10) 70%
Passmed
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