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Assertion : the cardiac impulse which or...

Assertion : the cardiac impulse which originates from SA node in mammalian heart cannot spread directly from atria to ventricles.
Reasoning : In mammalian heart, there is no continuity between muscle fibers of atria and those of ventricles except AV bundles.

A

If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).

B

If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2).

C

If Assertion is true statement but Reason is false, then mark (3).

D

If both Assertion and Reason are false statements, then mark (4).

Text Solution

Verified by Experts

The correct Answer is:
A
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Explore conceptually related problems

A : The cardiac impulse which originates from SA node in mammalian heart cannot spread directly from atria to ventricles R : In mammalian heart there is no continuity between cardiac muscle fibres of atria and those of ventricles except AV bundles.

Assertion : The AV bundle is essential for the conduction of cardiac impulse. Reason: There is no continuity between the cardiac muscle fibers of the auricles and those of the ventricles.

Knowledge Check

  • The problem of electrical discontinuity caused in the normal heart by the connective tissue separating the atria from the ventricles is solved by

    A
    coordinating electrical activity in the atria with electrical activity in the ventricles by connecting them via the bundle of His
    B
    having the A-V node function as a secondary pacemaker
    C
    having an ectopic pacemaker
    D
    coordinating electrical activity in the atria with electrical activity in the venticles by connecting them via the vagus nerve

  • Read the following statements and select the correct ones (i) Nodal tissue is specialised cardiac musculature in human heart which has the ability to generate action potential due to an external stimuli (ii) Position of SAN - right corner of right atrium (iii) Position of AVN - right corner of ventricle (iv) AV bundle continues from AVN (v) Purkinje fibres are modified cardiac muscle fibres that originate from the atrioventricular node and spread into the two ventricles.

    A
    (i) and (ii)
    B
    (i) and (iii)
    C
    (ii),(iv) and (v)
    D
    all of these

  • Read the following statements and choose the correct option Statement 1 : Atria receive blood from all parts of the body which subsequenctly flows to ventricles Statement 2 : Action potential generated at sino-atrial node passes from atria to ventricles.

    A
    Action mentioned in Statement 1 is dependent on action mentioned in Statement 2
    B
    Action mentioned in Statement 1 is dependent on action mentioned in Statement 1
    C
    Actions mentioned in Statements 1 and 2 are independent of each other
    D
    Actions mentioned in Statement 1 and 2 are synchronous

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    In order for the blood to flow from right ventricle to left ventricle in mammalian heart, it must flow through

    Read the following statements about the internal structure of the human heart. I. Humans have a an auto - excitable , chambered , muscular and myogenic heat. II. The heart is mesodermal in origin and is present symmetrically between two lungs in the thoracic cavity. III. The opening between the right atrium and left ventricle is guarded by a tricuspid valve. IV. Only the sino - atrial node of the heart has hte ability to generate action potentials without any external stimuli. How many statement/s is/ are incorrect from the above ?

    P wave of ECG indicates 1. activation of SA node 2. depolarization of atrial muslces 3. spread of excitation from AV node to Purkinje fibres 4. repolarization of atria and depolarization of ventricles

    Identify the correct sequence of the cardiac cycle. (i) Blood through the pulmonary vein and vena cava enters in left and right atria respectively. (ii) AVN generates action potential for the ventricles. (iii) SAN bring about atrial systole . (iv) Ventricular systole pushes blood away from the heart .

    Read the following statements and choose the correct option Statement 1 : Atria receive blood from all parts of the body which subsequenctly flows to ventricles Statement 2 : Action potential generated at sino-atrial node passes from atria to ventricles.

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