An umbrella description for a wide variety of conditions in which there is increased deterioration of the structure or function (or both) of the body. Ageing causes a steady degeneration of many tissues and organs – for example, wrinkling of the skin, CATARACT and poor neuromuscular coordination. In degenerative disorders the changes occur earlier in life. The nervous system, muscles, arteries, joints and eyes are all susceptible. Specialised tissues are replaced by CONNECTIVE TISSUE. The commonest example in the nervous system is ALZHEIMER’S DISEASE, which causes dementia; while in HUNTINGTON’S CHOREA, a genetic disorder, dementia is accompanied by incoordination of movements.
Article Categories:Medical Dictionary