superior thyroid artery

The superior thyroid artery arises from the external carotid artery just below the level of the greater cornu of the hyoid bone and ends in the thyroid gland. Structure From its origin under the anterior border of the sternocleidomastoid the superior thyroid artery runs upward and forward for a short distance in the carotid triangle, where it is covered by the skin, platysma, and fascia; it then arches downward beneath the omohyoid, sternohyoid, and sternothyroid muscles. To its medial side are the inferior pharyngeal constrictor muscle and the external branch of the superior laryngeal nerve. Branches It distributes twigs to the adjacent muscles, and numerous branches to the thyroid gland, connecting with its fellow of the opposite side, and with the inferior thyroid arteries. The branches to the gland are generally two in number. One, the larger, supplies principally the anterior surface; on the isthmus of the gland it connects with the corresponding artery of the opposite side. A second branch descends on the posterior surface of the gland and anastomoses with the inferior thyroid artery.