Thyroid anatomy

Question 1

Where is the thyroid gland?

Answer 1

Anterior neck, spanning between C5 and T1.

Inferior to thyroid cartilage and behind the sternohyoid & sternothyroid muscles.

Two lobes connected by isthmus - butterfly shape

Question 2

Where does the thyroid develop initially?

Answer 2

Floor of primitive pharynx, near base of tongue. It descends down the neck to get to its adult position.

Question 3

Which arteries supply the thyroid.

Answer 3

Superior & Inferior thyroid arteries

Question 4

Where does the superior thyroid artery arise from?

And which part of the thyroid does it supply?

Answer 4

Branch of external carotid

Superior and anterior portions of thyroid

Question 5

Where does the inferior thyroid artery arise from?

And which part of the thyroid does it supply?

Answer 5

Branch of thyrocervical trunk, which is a branch of the Subclavian

Postero-inferior region of thyroid

Question 6

In 10% of people there’s another artery present supplying the thyroid - name it, describe its origin and where it supplies.

Answer 6

Thyroid ima artery

Branch of brachiocephalic trunk, which comes from aortic arch.

Supplies the anterior surface and isthmus

Question 7

What’s the nerve supply of the thyroid?

Answer 7

Branches derived from sympathetic trunk.

Question 8

What controls endocrine secretion in the thyroid?

Answer 8

Pituitary gland - not nerves