Anatomy of the Thyroid and Parathyroid glands(Anatomy) Flashcards
What are the anatomical relations of the thyroid gland(3)
Anterior:-Infrahyoid muscles, sternothyroid, sternohyoid, omohyoid.
Laterally:- Carotid sheath
Medially:-Organs-Larynx, pharynx, trachea, oesophagus.
:-Nerves- external laryngeal and recurrent laryngeal
Describe the embryological development of the thyroid gland(4)
Origins- It originates from the thyroid diverticulum, pouch-like structures that develop from the foramen caecum.
Migration- migrate towards the anterior of the trachea.
Diverticulum transformation- proliferation and differentiation of the diverticulum to become bilobed.
Thyroglossal duct- connects the thyroid gland to the tongue during migration, typically degenerates.
Explain the blood supply process for the thyroid gland
Arteries resp are:
Superior thyroid artery:-Arises as the first branch from the external carotid artery.
:-divides into the anterior and posterior branches
:-Supplies the upper part of the gland.
Inferior thyroid artery:-arises from the thyrocervical trunk or subclavian artery.
:-supplies the lower part of the thyroid gland.
Thyroid ima artery:- arises from the brachiocephalic trunk or aortic arch.
:- supplies the isthmus and lower part of the gland.
Where are the parathyroid glands located?
On the posterior surface of the thyroid gland.
Which blood vessels supply the parathyroid glands?
Branches of the inferior thyroid arteries
Function of the parathyroid glands
They are resp for the regulation of calcium and phosphates by secreting PTH which influences bone, kidney and intestinal function.
Describe the embryological development of the parathyroid glands.
Superior parathyroid glands
-Derived from the fourth pharyngeal pouch.
-Located in the middle of the posterior boarder of each thyroid lobe.
-Approx 1 cm superior to the entry of the inferior thyroid artery into the thyroid gland.
Inferior parathyroid glands
-Derived from the third pharyngeal pouch.
- location is inconsistent but they are usually found near the inferior poles of the thyroid gland.
Venous drainage of the thyroid gland is made possible by which veins?(3)
Superior, middle and inferior thyroid veins