During exercise, your heart rate can increase dramatically in order to meet the metabolic demands of your tissues. If your heart rate increased to 144 beats per minute, approximately how long would diastole last?
A)0)2 second
B)0)6 second
C)0)8 second
D)1)6 seconds

Question

Quizplus · Accepted Answer

Diastole is the phase of the cardiac cycle when the heart muscles relax and the heart fills with blood. During exercise, the heart rate increases, and as a result, the duration of each cardiac cycle shortens. At a heart rate of 144 beats per minute, the duration of each cardiac cycle would be approximately 0.42 seconds (60 seconds divided by 144 beats per minute). The systole (contraction) phase of the cardiac cycle lasts for approximately 0.3 seconds, leaving the remaining time of 0.12 seconds for diastole. Therefore, diastole would last for approximately 0.08 seconds, which is the closest option to the answer.

During Exercise, Your Heart Rate Can Increase Dramatically in Order