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.
Proteins in the human immune system that help fight foreigninvaders, especially pathogens and toxins.
A substance capable of stimulating an immune response or reaction.
The practice of inhibiting the growth and multiplication of microorganisms, usually by ensuring the cleanliness of the environment.
An antigen-presenting cell—a macrophage that has ingested a foreign cell and displays the antigen on its surface.
A type of white blood cell that gives rise to antibodies. Also known as a B lymphocyte.
The specific immune response that utilizes T cells to neutralize cells that have been infected with viruses and certain bacteria.
A cell or group of cells that filters material from the blood, processes that material, and secretes it either for use again in the body or to be eliminated as waste.
An iron-containing protein in red blood cells that is responsible for transporting oxygen to the tissues and removing carbon dioxide from them. Hemoglobin is known for its deep redcolor.
Of or relating to the antibodies secreted by B cells that circulate in bodily fluids.
A network of organs, glands, and tissues that protects the body from foreign substances.
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.
The study of the immune system, immunity, and immune responses.
That portion of the blood that includes white blood cells and plasma but not red blood cells.
Masses of tissue at certain places in the body that act as filters for blood.
A type of white bloodcell, varieties of which include B cells and Tcells, or B lymphocytes and T lymphocytes.
A type of phagocyticcell derived from monocytes.
Major histocompatibility complex, a group of proteins found on the membrane of each cell in an organism's body. Since all cells in a particular body have the same MHC pattern, the MHC is a kind of pass code, identifying cells in the body as belonging to the "self."
A type of white blood cell that phagocytizes (engulfs and digests) foreign microorganisms.
A disease-carrying parasite, usually a microorganism.
A cell that engulfs and digests another cell.
A type of white blood cell, 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.
A group of cells, along with the substances that join them, which form part of the structural materials in plants oranimals.
Blood cells that are colorless, lack hemoglobin, have anucleus, and include the lymphocytes and other varieties.