GENERAL HISTOLOGY

Detailed explanation-1: -The effects of aging on the immune system are manifest at multiple levels that include reduced production of B and T cells in bone marrow and thymus and diminished function of mature lymphocytes in secondary lymphoid tissues. As a result, elderly individuals do not respond to immune challenge as robustly as the young.

Detailed explanation-2: -T cells can wipe out infected or cancerous cells. They also direct the immune response by helping B lymphocytes to eliminate invading pathogens. B cells create antibodies. B lymphocytes, also called B cells, create a type of protein called an antibody.

Detailed explanation-3: -Thus, aging is associated with an increase in the number of antigen-experienced cells and a decrease in the number of naïve T cells in the peripheral blood6 as well as an increase in the number of natural killer and natural killer/T cells.