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Assertion : The sino-atrial node (SAN) i...

Assertion `:` The sino-atrial node (SAN) is called the pacemaker.
Reason `:` SAN is responsible for initiating and maintaining the rhythmic contractile activity of the heart.

A

If both assertion and reason are true and reason is the correct explanation of assertion.

B

If both assertion and reason are true but reason is not the correct explanation of assertion

C

If assertion is true but reason is false.

D

If both assertion and reason are false

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The correct Answer is:
A
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Which is responsible for initiating and maintining the rhythmic contractile activity of the heart ?

Sino-atrial node is called the pacemaker of our heart. Why?

A patch of nodal tissue responsible for initiating the rhythmic contractile activity of heart is present in

Assertion : Sino-atrial node (SAN) is called the pacemaker Reason : SAN generates the maximum number of action potentials and is responsible for intiating and maintaining the rhythmic contractions of the heart.

Which of the following statements are correct about Sino-atrial node A) It is responsible for initiating and maintaining the rhythmic contractile activity of the heart B) It is auto-excitable and generates 70 - 75 action potentials per minute C) It sets the pace of the activities of the heart and is called pacemaker

Why is sinuatrial (SA) node also called the pacemaker of heart?

a. SAN generates as action potential which stimulates atrial systole. b. ECG is an electrical representation of the graphical activity of the heart during a cardiac cycle. c. The cardiac output of a normal man will be much lesser than an athlete. d. The wall of right ventricle is much thicker than the left ventricle e. In pisces the two separate circulatory pathways are present, hence they have double circulation. f. The clsoed circulatory pattern is considered to be more advantageous than open circulatory pattern. g. Glucose is absorbed by simple diffusion through lymph in lacteales present in the intestinal villi. h. The SAN can generate the maximum number of action potential i.e. 140-150 mi n^(-1) in neonates, and is responsible for initiation and maintenance of the rhythmic contractile activity of the heart. i. Angina can occur in any age but more common among the neonates and infants. j. heart failure is sometimes called congestive heart failure because congestion of the blood vessels is one of the main symptoms of this disease.

MOTION-BODY FLUIDS AND CIRCULATION-EXERCISE -4 AIIMS | Assertion & Reason Questions
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  4. Assertion :- If all external nerve supplies to a human heart are cut t...

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  5. Assertion :- Lymph is the filtered blood from capillaries, which is ri...

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  6. Assertion : In joint diastole, all the four chamber of heart are in r...

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  7. Assertion : The pause between the end of the second sound and the beg...

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  8. Assertion : LUBB (First Sound) is of shorter duration and sharp sound...

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  9. Assertion : Portal system consists of veins which start from capillari...

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  10. Assertion: Atherosclerosis affects the vessels that supply blood to th...

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  11. Assertion : In amphibians incomplete double circulation presents. Re...

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  12. Assertion : In open circulatory system blood is pumped by heart passes...

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  13. Assertion: In fishes single circulation occur Reason : Fishes have a...

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  14. Assertion : Myocardial infarction oftern results from a sudden decreas...

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  15. Assertion : The sino-atrial node (SAN) is called the pacemaker. Reas...

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  16. Assertion : The opening between the right atrium and the right ventric...

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  17. Assertion : Neural signals through the sympathetic nerves can increase...

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  18. Assertion : Cardiac output is the volume of blood pumped out by each v...

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  19. Assertion : First heart sound (LUBB) is produced at the beginning fo v...

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  20. Assertion : Lymph is a colourless fluid containing specialised lymphoc...

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