Template - an outline form which can be used to make many identical copies without being used itself. Metal templates can be used placed over a piece of clothing material, which is then cut according to the shape of the template. Many pieces can be made from the same template, and they will all be the right shape for that part of the garment. Molecular templates can guide the formation of crystals by providing a shape which is characteristic of, for example anapatite crystal. The role of templates in crystal formation is calledepitaxy.

Temporomandibular joint - the joint between the condyle of the mandible and the glenoid fossa of the temporal bone. The joint is divided into an upper and lower compartment by a fibrous disc and surrounded by a capsule.

Tenascin - an adhesive molecule of connective tissue related to fibronectin andlaminin.

Thalamus - the major co-ordinating centre or sensory6 information in the brain.

Threshold - the minimum level of a signal(sound. pressure, pain) which is detectable.

Thrombin - the final chain in the series of blood clotting8 forms fibrin from fibrinogen. Thrombin is formed from prothrombin by a prothrombin activator, itself the end of a series of reactions. This cascade of events may begin two ways. One, is the release of tissue factors from damaged vessels. The other, is the activation of factors in blood platelets which are altered by coming into contact with collagen or an artificial surface.

Thromboxanes - concerned with platelet clotting and a member of the eicosanoid family of hormones