Dr Gawad Physiology Course Online Exam - CVS – Course Lecture 2 – Excitability, Conductivity, Contractility

8 Questions | Total Attempts: 354

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Dr Gawad Physiology Course Online Exam - CVS  Course Lecture 2  Excitability, Conductivity, Contractility - Quiz

8 MCQs (Only one correct answer) Each MCQ: 1 mark, Total mark: 8 (you will get your result immediately by the web) Allowed time: 8 min Good Luck dr Mohammed Abel Gawad


Questions and Answers
  • 1. 
    The most rapid conduction velocity is present:
    • A. 

      The SAN.

    • B. 

      The AVN.

    • C. 

      The ventricular muscle.

    • D. 

      The Purkinje fibres.

  • 2. 
    About the cardiac conductivity, all the following is true except:
    • A. 

      It is slowest in the AV node.

    • B. 

      It is maximal in the Purkinje fibres.

    • C. 

      It is slowest in the ventricular muscle.

    • D. 

      It is decreased by vagal stimulation.

    • E. 

      It occurs through modified cardiac muscle fibres.

  • 3. 
    In the AV conduction all the following is true except:
    • A. 

      Conduction is the slowest.

    • B. 

      Conduction is delayed.

    • C. 

      Conduction is usually difficult in the ventriculo-atrial direction.

    • D. 

      Conduction is enhanced by sympathetic stimulation.

  • 4. 
    The fibres of the A-V bundle & its branches :
    • A. 

      Conduct impulses very slowly.

    • B. 

      Are highly contractile.

    • C. 

      Are modified muscle fibres.

    • D. 

      Are nerve fibres

    • E. 

      A & c

  • 5. 
    The main function of the cardiac Purkinjie system is to :
    • A. 

      Increase the speed of impulse conduction through the cardiac muscle.

    • B. 

      Prevent premature ventricular beats.

    • C. 

      Coordinate the valve movements with myocardial contraction.

    • D. 

      Enable all parts of the ventricle to contract simultaneously.

    • E. 

      Delay the systole until the ventricles fill.

  • 6. 
    About cardiac contractility all the following is true except:
    • A. 

      It depends on the interaction between actin and myosin.

    • B. 

      It increases when the serum K+ rises above normal.

    • C. 

      It is lost if the bathing medium is made calcium-free.

    • D. 

      It needs ATPase activity during systole and diastole

  • 7. 
    Within physiological limits, if the EDV is increased:
    • A. 

      The force of cardiac contraction is increased.

    • B. 

      The cardiac output is increased.

    • C. 

      Starling's law is applicable.

    • D. 

      All of the above.

  • 8. 
    Regarding cardiac cells excitability which is true:
    • A. 

      ARP is too short

    • B. 

      Tetany may occur on reptetive stimulation

    • C. 

      Heart is applying all or none rule

    • D. 

      None of the above

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