Substance that the body recogines as foreign;evokes an immune response. Most antigens are proteins or proteins fragments found on the surface of bacteria, viruses, or organ transplant tissue cells.
B cell (B lymphocyte)
Lymphocyte that originates in the bone marrow and transforms into a plasma cell to secrete antibodies. The B refers to the bursa of Fabricius, an organ in birds in which B cell differentiation and growth were first noted to occur.
Proteins that aid and regulate the immune response. Examples are interferons and interleukins.
Specialized macrophage that disgests foreign cells and helps B and T cells to mark antigens for destruction.
Helper T cell
Lymphocyte that aids B cells and cytotoxic T cells in recognizing antigens and stimulating antibody production;also called CD4+ cell or T4 cell.
Body's ability to resist foreign organisms and toxins. This includes natural immunity and acquired immunity.
Antibodies (gramma globulins) such as IgA, IgE, IgM, and IgD that are secreted by plasma cells in response to the presence of an antigen.
Fluid in the spaces between cells. This fluid becomes lymph when it enters lymph capillaries.
Thin watery fluid found within lymphatic vessels and collected from tissues throughtout the body. Latin lympha means clear spring water.
Carrier of lymph throughout the body; lymphatic vessels empty lymph into veins in the upper part of the chest.
Antibody produced in a laboratory to attack antigens and to destroy cells. It is useful in immunotherapy.
Right lymphatic duct
Large lymphatic vessel in the chest that receives lymph from the upper right part of the body.
Suppressor T cell
Lymphocyte that inhibits the activity of B and T lymphocytes. Also called a Teg (regulatory T cell).
T cell (T lymphocyte)
Lymphocyte that originates in the bone marrow but matures in the thymus gland; it acts directly on antigens to destroy them or produce chemicals (cytokines) such as interferons and interleukins that are toxic to antigens.
The ability of T lymphocytes to recognize and accept the body's own antigens as self or friendly. Once tolerance is established, the immune system will not react against the body.
Large lymphatic vessels in the chest that receives lymph from below the diaphragm and from the left side of the body above the diaphragm; it empties the lymph into veins in the upper chest.
Organ in the mediastinum that conditions T lymphocytes to react to foreign cells and aids in the immune response.
Exposure of an individual to a foreign protein (antigen) that provokes an immune response. The response will destroy any cell that processes the antigen on its surface and will protect against infection. The term comes from the Latin vacca, cow- the first inoculations were given with organisms that caused the disease cowpox to produced immunity to smallpox.
Weakened or killed microorganisms, toxins, or other proteins given to induced immunity to infection or disease.
Interstitial fluid collects within the spaces between cells as a result of obstruction of lymphatic vessels and nodes.
Note that the combing form for spleen contains only one e.
asplenia-the condition may be congenital or result from surgical removal.
hypersplenism-a syndrome marked by splenomegaly and often associated with blood cell destruction, anemia, leukopenia, and thrombocytopenia.
ana- again, anew
The suffix-phylaxis means protection. This is an exaggerated or unusual hypersensitivity to previously encountered foreign proteins or other antigens. Vasodilation and a decrease in blood pressure can be life-threatening.