immunity cells

B lymphocytes

produces antibodies

-fight circulating bacteria and viral infections

-become plasma cells when they enter tissues

-related to antibodies in blood

-humoral immunity

T lymphocytes

-come from thymus gland

-fight intercellular viruses, fungi, parasites, and cancer

-cellular immunity

B cells

Antigen

-antibody binding

Plasma cells

Replicated B cells

Helper T cells

Stimulate production of

-killer T cells

-more B cells

Killer T cells

-bind to antigens or infected cells

-attack virus-invading the body’s cells

-attack cancer cells

-reject body grafts

-need to shut these down for transplants

Memory cells

Descendants of activated T and B cells

-recognizes antigens to allow for quicker response

-from vaccines when you are a child

Suppressor T cells

Slow down activities of B and T cells

-inhibits production of antibodies

-occurs weeks after infection

Macrophages

-engulfs and digest antigen

-present them to T cells for recognition

Lymphokines

Chemicals released by sensitized T cells

Monokines

Chemicals released by activated macrophages

Skin

Mechanical barrier

-acid mantle, sebum

Lysozyme

Attacks bacteria (tears and saliva)

-breaks down cell wall of bacteria

Mucous membrane

Trap microorganisms and debris

Hydrochloric acid

Destroys microorganisms