Term | Definition |
lymph | the name for tissue fluid that enters lymph capillaries. |
lymph capillaries | very permeable and collect tissue fluid and proteins. |
lacteals | specialized lymph capillaries in the villi of the small intestine; they absorb the fat-soluble end products of digestion,(such as fatty acids and vitamins A,D,E, and K.) |
skeletal muscle pump | a mechanism that increases venous return; contractions of the skeletal muscles compress the deep veins, especially those of the legs. |
respiratory pump | a mechanism that increases venous return; pressure changes during breathing compress the veins that pass through the thoracic cavity. |
cisterna chyli | a large lymph vessel formed by the union of lymph vessels from the lower body; continues superiorly as the thoracic duct. |
thoracic duct | the lymph vessel that empties lymph from the lower half and upper left quadrant of the body into the left subclavian vein. |
lymph node | a small mass of lymphatic tissue located along the pathway of a lymph vessel; produces some lymphocytes and destroys pathogens in the lymph. |
plasma cells | a cell derived from an activated B cell that produces antibodies to a specific antigen. |
lymph nodule | a small mass of lymphatic tissue located in a mucous membrane; destroys pathogens that penetrate mucous membranes. |
tonsils | the lymph nodules in the mucosa of the pharynx, the palatine tonsils, and the adenoid; also the lingual tonsils on the base of the tongue. |
tonsillectomy | the surgical removal of the palatine tonsils and/or adenoid. |
Peyer's patches | the lymph nodules in the mucosa of the small intestine, especially in the ileum. |
spleen | an organ located in the upper left abdominal quadrant behind the stomach; consists of lymphatic tissue that produces lymphocytes; also contains macrophages that phagocytize old red blood cells. |
thymus | an organ made of lymphatic tissue located inferior to the thyroid gland; large in the fetus and child, and shrinks with age; produces T cells and hormones necessary for the maturation of the immune system. |
self-recognition | the ability to distinguish the cells that belong in the body from those that do not. |
self-tolerance | the ability not to react to proteins and other organic molecules our cells produce. |
immunity | the ability to destroy pathogens or other foreign material and to prevent further cases of certain infectious diseases. |
antigens | chemical markers that identify cells. |
natural killer cells | a type of lymphocyte that is not specific and is part of innate immunity; kills pathogens and tumor cells by direct contact. |
interferons | (alpha-, beta-, and gamma-interferons) are proteins produced by cells infected with viruses and by T cells. |
complement | a group of more than 20 plasma proteins that circulate in the blood until activated. |
inflammation | a general response to damage of any kind: microbial, chemical, or physical. |
cytokines | chemicals released by activated T cells that attract macrophages. are also released by many cells and tissues as part of cellular communication. |
cell-mediated immunity | the mechanism of adaptive immunity that does not involve antibody production, but rather the destruction of foreign antigens by the activities of T cells and macrophages. |
antibody-mediated immunity | the mechanism of adaptive immunity that involves antibody production and the destruction of foreign antigens by the activities of B cells, T cells, and macrophages. (Syn.-humoral immunity) |
antibody | a protein molecule produced by plasma cells that is specific for and will bond to a particular foreign antigen. (Syn.-gamma globulin, immune globulin) |
opsonization | the action of antibodies or complement that upon binding to a foreign antigen attracts macrophages and facilitates phagocytosis. |
vaccines | a preparation of a foreign antigen that is administered by injection or other means in order to stimulate an antibody response to provide immunity to a particular pathogen. |
agglutination | "clumping", this is what happens when antibodies bind to bacterial cells. |
genetic immunity | the immunity provided by the genetic makeup of a species; reflects the inability of certain pathogens to cause disease in certain host species. |
acquired immunity | the immunity obtained upon exposure to a pathogen or a vaccine or upon reception of antibodies for a particular pathogen. |
passive immunity | the immunity provided by the reception of antibodies from another source; may be natural (placental, breast milk) or artificial (injection of gamma globulins). |
active immunity | the immunity provided by the production of antibodies after exposure to a foreign antigen; may be natural (recovery from disease) or artificial (reception of a vaccine). |