Immune System Vocabulary

Flashcards on the Immune System

Immune response

A target-specific system of defense, primarily involving the lymphocytes and lymphoid tissue.

Immunocompetence

The ability to cooperatively protect a person from external invaders and the body’s own altered cells.

Leukocytes

White blood cells produced in bone marrow, including lymphocytes, neutrophils, and monocytes.

Lymphocytes

Primary participants in the immune response that distinguish harmful substances.

T-cell lymphocytes

cells that are either regulator or effector cells, maturing in the thymus gland.

Regulator T cells

T cells made up of helper and suppressor cells.

Helper T cells

T4 or CD4 cells important in fighting infection

Suppressor T cells

T cells that limit or turn off the immune response.

Effector T cells

Killer (cytotoxic) cells

Antigens

Protein markers on cells.

Antibodies

Chemical substances that destroy foreign agents.

Cell-mediated response

When T cells survey proteins in the body and attack those that differ from the host.

B-cell lymphocytes

Mature in bone marrow and migrate to the spleen and other lymphoid tissue

Plasma cells

Produce antibodies; humoral response from antibody response

Memory cells

Convert to plasma cells on reexposure to a specific antigen.

Neutrophils

Microphages that perform phagocytosis.

Monocytes

Macrophages that perform phagocytosis.

Phagocytosis

Process of engulfing and digesting bacteria and foreign material.

Thymus gland

Programs T lymphocytes to become regulator or effector T cells

Tonsils and adenoids

Filter bacteria from tissue fluid

Spleen

Emergency reservoir of blood and removes bacteria and old or damaged red blood cells from circulation

Lymph nodes

Vessels that drain tissue fluid (lymph)

Natural killer (NK) cells

Lymphocyte-like cells that circulate throughout the body looking for virus-infected cells and cancer cells. They identify atypical markers on the membranes of these cells and release potent chemicals that lethally alter the target cell’s membrane

Antibodies

Proteins produced by B-lymphocyte plasma cells, also known as immunoglobulins (Igs).

Immunoglobulins (Igs)

Five types: IgA, IgD, IgE, IgG, and IgM

Complement System

Many different proteins; activated in a chain reaction when an antibody binds with an antigen

Cytokines

Chemical messengers released by lymphocytes, monocytes, and macrophages

Opsonization

Proteins cooperate with antibodies to attract phagocytes, coat antigen to make them more recognizable for phagocytosis

Interleukins

Carry messages between leukocytes and tissues that form blood cells.

Interferons

Chemicals that primarily protect cells from viral invasion; enable cells to resist viral infection and slow viral replication

Tumor necrosis factor (TNF)

Helps in cellular repair when administered in small doses

Naturally acquired active immunity

Occurs as a direct result of infection by a specific microorganism

Artificially acquired active immunity

Results from administration of a killed or weakened microorganism or toxoid

Passive immunity

Ready-made antibodies are given to a susceptible person

Anergy

Inability to mount an immune response