Question

4.

Answer 1

In this case, the SA node depolarizes 80 times in a minute. SA node depolarization depends on electrical stimuli.

Sinoatrial node depolarization

The sinoatrial (SA) node can be considered as a fundamental pacemaker located in the heart.

This node (SA node) depends on electrical stimuli that spread in the atrial muscle to produce muscle contraction.

At a normal heart rate, the SA node depolarizes at a regular rate of 60-100 beats in a minute (min).

Learn more about the SA node here:

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