Question

which of the following occurs in the cardiac cycle if the impulse triggered at the sinoatrial node never closes? a. diastole will shorten in duration

b. the ventricles will not contract

c. there will be an absence of systole

d. thd atria will not contract

fyi: I’ve seen different answers for the same question!

Answer 1

SA node is called as the natural pace maker of the heart enabling the contraction of the heart by its stimulation through the nerves.When there is a block or damage the parts below it exhibits its function for time being.Normal when the impulse is triggered it contracts the ventricle and atria relaxes .This process can be stopped after the closing of SA impulse in case if it does not happen the atria will be in a relaxed state and will not contract

Ans:d.The atria will not contract