Superior thyroid artery
Encyclopedia
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.
To its medial side are the Constrictor pharyngis inferior and the external branch of the superior laryngeal nerve
.
The branches to the gland
are generally two in number;
Besides the arteries distributed to the muscles and to the thyroid gland, the branches of the superior thyroid are:
. 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 gain access to its origin from the external carotid artery
and ligate it there.
A surgeon tells a medical student to tap the side of the face of a patient who just had thyroid surgery. The surgeon is most worried about damage to which of the following vessels? Answer: Superior and inferior thyroid arteries. Why? These vessels also supply the parathyroid glands. If disrupted during surgery, necrosis of the parathyroids occurs, with subsequent hypocalcaemia and tetany. The masseter is a good muscle to test for tetany.
External carotid artery
In human anatomy, the external carotid artery is a major artery of the head and neck. It arises from the common carotid artery when it bifurcates into the external and internal carotid artery.-Course:...
just below the level of the greater cornu of the hyoid bone
Hyoid bone
The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly...
and ends in the thyroid gland.
Relations
From its origin under the anterior border of the Sternocleidomastoideus it 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 Omohyoideus, Sternohyoideus, and Sternothyreoideus.To its medial side are the Constrictor pharyngis inferior and the external branch of the superior laryngeal nerve
Superior laryngeal nerve
The superior laryngeal nerve is a branch of the vagus nerve. It arises from the middle of the ganglion nodosum and in its course receives a branch from the superior cervical ganglion of the sympathetic....
.
Branches
It distributes twigs to the adjacent muscles, and numerous branches to the thyroid gland, anastomosing with its fellow of the opposite side, and with the inferior thyroid arteries.The branches to the gland
Glandular branches of the superior thyroid artery
The glandular branches of the superior thyroid artery are generally two in number;* one, the larger, supplies principally the anterior surface; on the isthmus of the gland it anastomoses with the corresponding artery of the opposite side...
are generally two in number;
Besides the arteries distributed to the muscles and to the thyroid gland, the branches of the superior thyroid are:
- Hyoid (infrahyoid) artery
- Sternocleidomastoid arterySternocleidomastoid arterySternocleidomastoid artery can refer to:* Sternocleidomastoid branches of occipital artery* Sternocleidomastoid branch of superior thyroid artery...
- Superior laryngeal arterySuperior laryngeal arteryThe superior laryngeal artery accompanies the internal laryngeal branch of the superior laryngeal nerve, beneath the Thyreohyoideus.This artery branches from the superior thyroid artery near its bifurcation from the external carotid artery...
- Cricothyroid artery
Surgery
This artery must be ligated at the thyroid when conducting a thyroidectomyThyroidectomy
A thyroidectomy is an operation that involves the surgical removal of all or part of the thyroid gland. Surgeons often perform a thyroidectomy when a patient has thyroid cancer or some other condition of the thyroid gland...
. If the artery is severed, but not ligated, it will bleed profusely. In order to gain control of the bleeding the surgeon
Surgeon
In medicine, a surgeon is a specialist in surgery. Surgery is a broad category of invasive medical treatment that involves the cutting of a body, whether human or animal, for a specific reason such as the removal of diseased tissue or to repair a tear or breakage...
may need to extend the original incision laterally to gain access to its origin from the external carotid artery
External carotid artery
In human anatomy, the external carotid artery is a major artery of the head and neck. It arises from the common carotid artery when it bifurcates into the external and internal carotid artery.-Course:...
and ligate it there.
A surgeon tells a medical student to tap the side of the face of a patient who just had thyroid surgery. The surgeon is most worried about damage to which of the following vessels? Answer: Superior and inferior thyroid arteries. Why? These vessels also supply the parathyroid glands. If disrupted during surgery, necrosis of the parathyroids occurs, with subsequent hypocalcaemia and tetany. The masseter is a good muscle to test for tetany.