Question

explain regulations of heart activity​

Answer 1

Answer:

Heart rate is controlled by the two branches of the autonomic (involuntary) nervous system. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The sympathetic nervous system (SNS) releases the hormones (catecholamines - epinephrine and norepinephrine) to accelerate the heart rate.

Explanation:

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Answer 2

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Cardiac cycle helps in the circulation of blood. It includes systole (contraction of cardiac muscles) and diastole (relaxation of cardiac muscles). The cardiac cycle is a normal activity of the human heart and is regulated automatically by the nodal tissues- sinoatrial node (SA node) and atrioventricular node (AV node). The variation in the cardiac cycle results in an increase or decrease in the cardiac output.

The occurrence of a cardiac cycle is illustrated by the heartbeat rate, which is the number of beats per minute. Our heart beats 72 times per minute and is stated as 72 cardiac cycles per minute.

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