TIBIA

(Lat.), n. f. Ti2b(teb)'i2-a3. Gr., (cvij/mij, TTpoicvrj/jLiov. Fr., t. Ger., T. A long bone, the larger of the two of the leg, on the anterior and inner side of wnich it is placed. Its upper extremity bears two concave surfaces covered with cartilage, separated by the crucial spine, for articulation with the femur, and bears on each side two prominences, the external and internal tuberosities. The shaft is three-sided, smaller in the middle than at either end, its inner surface being subcutaneous. The lower extremity is enlarged transversely and projects downward on the inner side as the internal malleolus, presenting a concave surface for articulation with the astragalus: externally is a surface covered with cartilage for articulation with the fibula, and posteriorly are grooves for the tendons of the tibial is posticus and flexores digitorum ped is and pollicis long i. [L. 31, 142, 332.] T. minima. See FIBULA (1st def.). [s. 623]