Dictionary

MAC 1 Mycobacterium avium complex. 2 Membrane attack complex.

Macewen operation A surgical operation to repair inguinal hernia that was designed by Scottish surgeon Sir William Macewen.

machine, heart-lung See heart-lung machine.

macro- Prefix meaning large or long, as macrocephaly (an abnormally large head) and macrosomia (an overly large body). The opposite of macro- is micro-.

luteinizing hormone-releasing hormone A hormone that controls the production of luteinizing hormone in men and women. Abbreviated LHRH. See also luteinizing hormone.

luxation Complete dislocation of a joint. A partial dislocation is a subluxation.

Lyme disease An inflammatory disease that is caused by the bacterium Borrelia burgdorferi, which is transmitted to humans by the deer tick. The first sign of Lyme disease is a red, circular, expanding rash, usually radiating from the tick bite, followed by flu-like symptoms and joint pains. After the B. burgdorferi has entered the bloodstream,…

lymph The almost colorless fluid that travels through the lymphatic system, carrying cells that help fight infection and disease.

lymph gland See lymph node.

lymph node One of many small, bean-shaped organs located throughout the lymphatic system. The lymph nodes are important in the function of the immune response and also store special cells that can trap cancer cells or bacteria that are traveling through the body through the lymph. Also known as lymph gland.

lymph node, sentinel The first lymph node to receive lymphatic drainage from a tumor. The sentinel node for a given tumor is found by injecting a tracer substance around the tumor. This substance then travels through the lymphatic system to the sentinel node. The tracer substance may be a blue dye that can be tracked…

lymphadenitis The enlargement and/or inflammation of a lymph node. Lymphadenitis may have multiple causes and may involve a single lymph node or a group of lymph nodes. See also lymph node.