PATHOLOGY

Detailed explanation-1: -When a lymphocyte encounters its antigen in a peripheral lymphoid organ, the binding of the antigen to the receptors activates the lymphocyte, causing it both to proliferate and to differentiate into an effector cell.

Detailed explanation-2: -A primary immune response results in the generation of memory immune cells. When our bodies face an infection, they create long-living populations of memory B cells, helper T cells, and cytotoxic T cells with receptors that specifically recognize the antigens associated with the infectious pathogen.

Detailed explanation-3: -B lymphocytes, also called B cells, create a type of protein called an antibody. These antibodies bind to pathogens or to foreign substances, such as toxins, to neutralize them. For example, an antibody can bind to a virus, which prevents it from entering a normal cell and causing infection.

Detailed explanation-4: -Our bodies often respond with fever (heat inactivates many viruses), the secretion of a chemical called interferon (which blocks viruses from reproducing), or by marshaling the immune system’s antibodies and other cells to target the invader.