Corpus: Inferior thyroid artery

The inferior thyroid artery is an arterial branch from the thyrocervical trunk of the subclavian artery that supplies the thyroid gland with oxygen-rich blood.

The inferior thyroid artery ascends steeply in front of the longus colli muscle and the vertebral artery. It then swings medially, ascending behind the carotid sheath and its contained vessels, towards the thyroid gland. The artery is closely associated with the sympathetic trunk and the middle cervical ganglion.

Upon reaching the lower pole of the thyroid gland, the inferior thyroid artery divides into two branches (glandular branches), which supply the posteroinferior parts of the thyroid gland and anastomose with the superior thyroid artery.

The esophageal branches supply the upper parts of the esophagus and anastomose with the esophageal branches of the aorta.

The pharyngeal branches (also known as muscular branches) supply parts of the pharyngeal musculature and pharyngeal mucosa, anastomosing with the pharyngeal branches of the ascending pharyngeal artery.

The recurrent laryngeal nerve is usually found dorsal or posterior to the inferior thyroid artery. However, the relationship between the nerve and the artery can vary significantly. The nerve can also run ventral or anterior to the vessel.

• Inferior laryngeal artery
• Esophageal branches
• Tracheal branches
• Ascending cervical artery
• Pharyngeal branches
• Glandular branches

In addition to the inferior thyroid artery, an additional artery known as the thyroid ima artery may sometimes be present.

Ligation of the inferior thyroid artery, such as during a thyroidectomy, poses a risk of injury to the recurrent laryngeal nerve. Ligation of this artery can also lead to hypoparathyroidism, as it is the primary blood supply to the parathyroid glands.