MEDICAL PHYSIOLOGY

Detailed explanation-1: -In antibody responses, B cells are activated to secrete antibodies, which are proteins called immunoglobulins. The antibodies circulate in the bloodstream and permeate the other body fluids, where they bind specifically to the foreign antigen that stimulated their production (Figure 24-2).

Detailed explanation-2: -Any substance that causes the body to make an immune response against that substance. Antigens include toxins, chemicals, bacteria, viruses, or other substances that come from outside the body. Body tissues and cells, including cancer cells, also have antigens on them that can cause an immune response.

Detailed explanation-3: -The immunoglobulin recognizes and binds antigen but cannot itself generate a signal.