chorea Ceaseless, restless, rapid, complex body movements that look well coordinated and purposeful but are, in fact, involuntary. The term chorea is derived from the Greek word choreia, which means “dancing” (as is choreography) because chorea was thought to be suggestive of a grotesque dance. See also Huntington’s disease; Sydenham’s chorea.
chordoma A benign tumor, usually in the lower back, that originates from cells destined to form cartilage. These cells are remnants of the primitive notochord, the flexible rod of cells in the embryo that forms the supporting axis of the body. Chordomas induce bone destruction.
chorda tympani A branch of the facial nerve (the seventh cranial nerve) that serves the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain. The chorda tympani is part of one of three cranial nerves involved in taste.
chorda tendinea A thread-like band of fibrous tissue that attaches on one end to the edge of the tricuspid and mitral valves of the heart and on the other end to the papillary muscle within the heart. The chorda tendinea serves to anchor the valves.
chondrosarcoma A malignant tumor that arises in cartilage cells (chondroblasts). Chondrosarcoma can be primary or secondary. Primary chondrosarcoma forms in bone and is a disease in children. Secondary chondrosarcoma arises from a preexisting benign defect of cartilage (such as an osteochondroma or enchondroma), usually after age 40. The main treatment is surgery. See also cartilage;…
chondroplasia The formation of cartilage by specialized cells called chondrocytes.
chondromalacia patella See patellofemoral syndrome.
chondromalacia Abnormal softening or degeneration of cartilage. See also patellofemoral syndrome.
chondrocalcinosis Calcium deposition in cartilage. Chondrocalcinosis can be associated with degenerative arthritis, pseudogout, hemochromatosis, hyperparathyroidism, diabetes, hypomagnesemia, and Wilson’s disease.
cholesterol gallstone Stone within the gallbladder that is a result of chronically elevated blood levels of cholesterol (hypercholesterolemia). This can lead to inflammation of the gallbladder (cholecystitis). See also cholecystitis.
cholesterol, lowering with niacin Niacin, also known as nicotinic acid, is a water-soluble B vitamin that improves levels of all lipoproteins when given in doses well above the vitamin requirement. Niacin lowers the total cholesterol, LDL cholesterol, and triglyceride levels, while raising the HDL cholesterol level. A common and troublesome side effect of niacin is…
cholesterol, lowering with fibrates Lowering cholesterol levels through the use of cholesterollowering drugs that are primarily effective in lowering triglycerides and, to a lesser extent, in increasing HDL levels. Gastrointestinal complaints are the most common side effect, and fibrates appear to increase the likelihood of a patient’s developing cholesterol gallstones.