Diastole is the ________ phase of the cardiac cycle.
A. Contraction
B. Relaxation
C. Monitoring
D. Termination
http://biology.about.com/od/anatomy/a/aa060404a.htm
It's B - I've taken this test
The correct answer is B. Relaxation.
To determine the correct answer, you can start by understanding what the cardiac cycle is. The cardiac cycle refers to the sequence of events that happen during one heartbeat. It consists of two main phases: diastole and systole.
During diastole, the heart is in a state of relaxation. This is the period when the heart chambers (ventricles and atria) are filling up with blood. The relaxation allows the heart to refill with blood and prepare for the next contraction (systole). This process ensures an adequate blood supply to the body.
On the other hand, systole is the contraction phase of the cardiac cycle. It occurs after diastole and involves the pumping of blood out of the heart chambers into the blood vessels.
Considering the given options, A. Contraction (referring to systole), C. Monitoring, and D. Termination are not accurate descriptions of the diastolic phase. Thus, the correct answer is B. Relaxation, which accurately describes diastole as the phase in which the heart is in a state of relaxation.