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The parathyroid glands |
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• They are small, yellowish-brown endocrine glands • Located posterior to the thyroid, in their own capsule, but sharing the same fascial investment. • The superior are thought to originate in the 4 th pharyngeal pouch. • The superior ones are consistent in position. •The inferior are inconsistent and could be found in the anterior mediastinum. |
| Blood supply | |
• Usually by the inferior thyroid arteries but may be supplied by the superior thyroid arteries or from longitudinal anastomosis between superior and inferior thyroid arteries. • The veins drain into the thyroid plexus of the veins on the anterior surface of the thyroid. |
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| Lymphatics of the Parathyroid glands | |
• Inferior deep cervical lymph nodes. • Paratracheal lymph nodes. The lymph vessels from here end in the thoracic duct. |
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| Innervation of the parathyroid glands | |
Autonomic from the cervical sympathetic chain (and vagus). These are vasomotor. |
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| Functions of parathyroid glands | |
• The parathyroid glands are essential for regulation of blood calcium. (What are the functions of calcium in the body?) • They are in danger of being destroyed or removed during thyroidectomy. Surgeons usually leave bits of the thyroid posteriorly or identify and preserve at least one of them. |
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