Active Immunity

Immunity produced by an encounter with an antigen; provides immunologic memory.

Antibody

A specialized substance produced by the body then provides immunity against a specific antigen

Antigen

Substances including tarins, foriegen proteins, or bacteria that when introduced to the body, is recognized as foreign, activating immune respone

Appendix

Wormlike entension of the large intestine

Autoimmune

Production of antibodies or effector T cells that attack a person's own tissue

B Cells

Lymphocytes that oversee humoral immunity; their descendants differentiate into antibodies producing plasma cells

Cellular immunity

Immunity conferred by lymphocytes called T cells

Chemotaxis

Latter part of the inflammatory process associated with activation of pain receptors, phagocytes, and WBC's

Edema

An adnormal accumulation of fluid in body parts of tissues, causing swelling

Hilus

Depressed area where vessels enter or leave an organ

Histamine

Substance that causes vasodilation and increased vascular permeability

Humoral Immunity

Immunity provided by antibodies released by sensitized B cells and their plasma cell progeny

Hypersensitivity

Abnormal vigorus immune responses in which the immune system causes tissue damage as it fights off a perceived threat

Immunoglobins

Protein molecule, released by plasma cells, that medicates humoral immunity; an antibody

Immunocompetent

Condition when the body's immune cells recognize specific antigens; reflects the presence of plasma membrane-bound receptors

Immunodeficiencies

Maladies resulting from deficient production or function of immune cells or certain molecules required for normal immunity

Inflammatory Response

Physiological response of the body to tissue injury; includes dilation of blood vessels and increased vessel permability

Kinins

Group of polypeptides that dilate arterioles, increase vascular permeability, and induce pain

Lymph

Watery fluid in the lymph vessels collected from the tissue spaces

Lymph Nodes

Masses of lymphatic tissue

Lymph Vessels

Form a one-way pathway for lymph to flow from capillaries back to the heart

Macrophages

Cells particulary abudant in the lyphatic and connective tissues; important in immune response as an antigen-presenter to T cells and B cells

Nonspecific defenses

Bodys first defense against all foreign substances. These include skin, mucous, the inflammatory response, and cells

Passive immunity

Short-lived immunity resulting from the introduction of "borrowed antibodies" obtained from animal or human donor

Peyer's patches

Small masses located in the wall of the small intestine containing macrophages that destroy large numbers of bacteria

Phagocytes

Cells capable of engulfing and digesting particles or cells harmful to the body

Specific defense system

Mounts the attack against foriegn sunstances

Spleen

Blood-rich organ that destroys worn-out RBC's and filters blood of bacteria, viruses, and other debris

T cells

Lymphocytes that medicate cellular immunity; includes helper, killer, suppressor, and memory cells

Thymus gland

Produces lymphocyes so they can carry out their protective roles in the body

Tonsils

Small masses of lymphatic tissue that ring the pharynx. They trap and remove bacteria or other foreign pathogens entering the throat