Anatomy of the Thyroid and Parathyroid glands(Anatomy)

Question 1

What are the anatomical relations of the thyroid gland(3)

Answer 1

Anterior:-Infrahyoid muscles, sternothyroid, sternohyoid, omohyoid.
Laterally:- Carotid sheath
Medially:-Organs-Larynx, pharynx, trachea, oesophagus.
:-Nerves- external laryngeal and recurrent laryngeal

Question 2

Describe the embryological development of the thyroid gland(4)

Answer 2

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.

Question 3

Explain the blood supply process for the thyroid gland

Answer 3

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.

Question 4

Where are the parathyroid glands located?

Answer 4

On the posterior surface of the thyroid gland.

Question 5

Which blood vessels supply the parathyroid glands?

Answer 5

Branches of the inferior thyroid arteries

Question 6

Function of the parathyroid glands

Answer 6

They are resp for the regulation of calcium and phosphates by secreting PTH which influences bone, kidney and intestinal function.

Question 7

Describe the embryological development of the parathyroid glands.

Answer 7

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.

Question 8

Venous drainage of the thyroid gland is made possible by which veins?(3)

Answer 8

Superior, middle and inferior thyroid veins