Immunity and Immunology - Key terms
ALLERGY:
A change in bodily reactivity to an antigen as a result of a first exposure. Allergies bring about an exaggerated reaction to substances or physical states that normally would have little significant effect on a healthy person.
ANTIBODIES:
Proteins in the human immune system that help the body fight foreign invaders, especially pathogens and toxins.
ANTIGEN:
A substance capable of stimulating an immune response or reaction.
APC:
An antigen-presenting cell—a macrophage that has ingested a foreign cell and displays the antigen on its surface.
B CELL:
A type of white blood cell that gives rise to antibodies. Also known as a B lymphocyte.
EPIDEMIC:
Affecting or potentially affecting a large proportion of a population ( adj. ) or an epidemic disease ( n. )
HUMORAL:
Of or relating to the antibodies secreted by B cells that circulate in bodily fluids.
IMMUNE SYSTEM:
A network of organs, glands, and tissues that protects the body from foreign substances.
IMMUNITY:
The condition of being able to resist a particular disease, particularly through means that prevent the growth and development or counteract the effects of pathogens.
IMMUNOLOGY:
The study of the immune system, immunity, and immune responses.
INOCULATION:
The prevention of adisease by the introduction to the body, in small quantities, of the virus or other microorganism that causes the disease.
LYMPHOCYTE:
A type of white bloodcell, varieties of which include B cells and Tcells, or B lymphocytes and T lymphocytes.
MACROPHAGE:
A type of phagocyticcell derived from monocytes.
MONOCYTE:
A type of white blood cell that phagocytizes (engulfs and digests) foreign microorganisms.
MONOGAMOUS:
Having only one mate.
PATHOGEN:
A disease-carrying parasite, usually a microorganism.
PHAGOCYTE:
A cell that engulfs and digests another cell.
T CELL:
A type of lymphocyte, also known as a T lymphocyte, that plays a key role in the immune response. T cells include cytotoxic T cells, which destroy virus-infected cells in the cell-mediated immune response; helper T cells, which are key participants in specific immune responses that bind to APCs, activating both the antibody and cell-mediated immune responses; and suppressor T cells, which deactivate T cells and B cells.
VACCINE:
A preparation containing microorganisms, usually either weakened or dead, which are administered as a means of increasing immunity to the disease caused by those microorganisms.