tattoo

tattoo The permanent insertion of ink below the skin, using a sharp instrument. Humans have done tattooing for cosmetic and ritual purposes since at least the Neolithic era. Today the practice is made relatively safe by the use of nonreactive pigments; sterile, disposable needles; and sterile work conditions. Without these refinements, inks may cause inflammation,…

taste

taste A perception that results from stimulation of a gustatory nerve. Taste belongs to the chemical sensing system. Tasting begins when molecules stimulate special cells in the mouth or throat. These special cells transmit messages through nerves to the brain, where specific tastes are identified. Gustatory, or taste, cells react to food and beverages. The…

tartar

tartar The hardened product of minerals from saliva and foods that accumulates in plaque around the teeth. Dental plaque and tartar cause periodontal disease, including inflammation of the bone surrounding the teeth. Tartar can become as hard as rock, becoming removable only by a dentist or dental hygienist with special tools.

tarsal tunnel syndrome

tarsal tunnel syndrome Symptoms caused by compression of the nerve in the ankle and foot, usually from the trauma of repetitive work involving the ankle. Abbreviated TTS. Obesity, pregnancy, hypothyroidism, arthritis, and diabetes predispose a person to TTS. Symptoms include numbness and tingling of the foot and toes, a “pins and needles” feeling at night,…

tardive dyskinesia

tardive dyskinesia A neurological syndrome characterized by repetitive, involuntary, purposeless movements caused by the long-term use of certain drugs called neuroleptics used for psychiatric, gastrointestinal, and neurological disorders. Features may include grimacing; tongue protrusion; lip smacking, puckering, and pursing; and rapid eye blinking. Rapid movements of the arms, legs, and trunk may also occur. The…

TAR syndrome

TAR syndrome Thrombocytopenia–absent radius syndrome, in which the platelets needed for blood to clot normally are too few in number and the radius (the smaller of the two bones of the forearm) is absent, resulting in phocomelia (a “flipper” limb). The fibula (the smaller bone in the lower leg) is also often absent. The risk…