Question

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

Answer 1

Answer:

The cardiac cycle is the performance of the human heart from the ending of one heartbeat to the beginning of the next. ... (See Wiggers diagram, which presents the stages, label-wise

Answer 2

• cardiac cycle is the performance of the human heart from the ending 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, dubbed systole.

• heartbeat is a two-part pumping action that takes about a second. As blood collects in the upper chambers (the right and left atria), the heart's natural pacemaker (the SA node) sends out an electrical signal that causes the atria to contract.

• immunology, an antigen is a molecule or molecular structure, such as may be present on the outside of a pathogen, that can be bound by an antigen-specific antibody or B-cell antigen receptor. The presence of antigens in the body normally triggers an immune response.

• antibody, also known as an immunoglobulin, is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen.