Superior thyroid arteries

Superior thyroid artery
Superficial dissection of the left side of the neck, showing the carotid and subclavian arteries.
The fascia and middle thyroid veins. (Superior thyroid artery labelled at upper left.)
Details
Source	external carotid artery
Branches	Hyoid artery Sternocleidomastoid artery Superior laryngeal artery Cricothyroid artery
Vein	superior thyroid vein
Supplies	thyroid
Identifiers
Latin	Arteria thyreoidea superior
Dorlands /Elsevier	a_61/12156385
TA	A12.2.05.002
FMA	49472
Anatomical terminology []

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.

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.

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.

Besides the arteries distributed to the muscles and to the thyroid gland, the branches of the superior thyroid are:

This artery must be ligated at the thyroid when conducting a thyroidectomy. If the artery is severed, but not ligated, it will bleed profusely. In order to gain control of the bleeding, the surgeon may need to extend the original incision laterally to ligate the artery at its origin at the external carotid artery. Furthermore, the external laryngeal branch of the superior laryngeal nerve courses in close proximity to the superior thyroid artery, making it at risk for injury during surgery.