Question

C. Define these terms.
1. Cardiac cycle
2. Heartbeat
3. Antigen
4. Antibody​

Answer 1

Answer:

1. The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next. It consists of two periods: one during which the heart muscle relaxes and refills with blood, called diastole, following a period of robust contraction and pumping of blood, called systole.

2.