ANATOMY

Detailed explanation-1: -Vaccination (immunization) is a way to trigger the immune response. Small doses of an antigen, such as dead or weakened live viruses, are given to activate immune system “memory” (activated B cells and sensitized T cells).

Detailed explanation-2: -The binding of the lymphocytes’ receptors to the antigens’ surface molecules stimulates the lymphocytes to multiply and to initiate an immune response-including the production of antibody, the activation of cytotoxic cells, or both-against the antigen.

Detailed explanation-3: -The induction of an adaptive immune response begins when a pathogen is ingested by an immature dendritic cell in the infected tissue. These specialized phagocytic cells are resident in most tissues and are relatively long-lived, turning over at a slow rate.

Detailed explanation-4: -In an immune response, the immune system recognizes the antigens (usually proteins) on the surface of substances or microorganisms, such as bacteria or viruses, and attacks and destroys, or tries to destroy, them. Cancer cells also have antigens on their surface.