Superior Thyroid Artery

The left lateral thyroid vein and the phrenic nerve arise from the branches of the superior trunk. The external jugular vein passes under the anterior part of the internal jugular notch of the thyroid gland and joins the internal jugular vein, which together with the inferior laryngeal vein forms the jugular vein bulb. The right lateral thyroid artery runs along the neck along with the right common carotid artery.

The superior thyroid artery (a. suprahyoidea) originates from the posterior part of the superior thyroid gland (see Fig. 9.24) and goes down to the lateral surface of the thyroid cartilage of the larynx. On this path it branches, approaching the thyroid artery, i.e., the external carotid artery or the latter (in 75% of cases), in 80% of cases to the right vagus nerves or from the latter to the sympathetic trunks. If they are not present, then the superior thyroid artery divides over the anterior end of the thyroid gland. The anterolateral branch supplies the middle lobe of the thyroid gland through its own artery, and the branches to the lateral lobes of the gland originate from the terminal arteries of the superior trunk. These branches join the internal carotid arteries or their superior branches. The posterolateral branches, together with the lower respiratory tract, supply the upper (medial) part of the thyroid gland during the prenatal period, even at the time of birth. After this time they