Thyroid and Parathyroid

Question 1

Describe the blood supply to the thyroid gland

Answer 1

Subclavian-> thyrocervical trunk-> inferior thyroid artery

External carotid-> superior thyroid artery

Question 2

What is the structural unit of the thyroid called? What does it contain?

Answer 2

Thyroid follicle, contains colloid

Question 3

What do follicular cells produce?

Answer 3

Thyroglobulin, converts into T3 and T4 before release

Question 4

What do parafollicular cells produce?

Answer 4

Calcitonin, found between follicles

Question 5

What cell types are found in the parathyroid gland?

Answer 5

Chief cells (darker) produce PTH
Oxyphil cells (lighter) don't secrete
Adipocytes (large white) fat storage

Question 6

What else is found between follicles?

Answer 6

Capillaries

Question 7

Describe the venous drainage of the thyroid

Answer 7

Drain laterally to internal jugular vein, central drainage to L brachiocephalic vein

Question 8

What is the thyroid ima artery?

Answer 8

Variant found in 3-10% of population, arises from aorta/brachiocephalic trunk to supply thyroid gland

Question 9

Name the layers that surround the thyroid gland (superficial->deep)

Answer 9

Skin, superficial fascia w/platysma muscle, investing fascia of neck, strap muscles, pretracheal fascia

Question 10

Describe the lymphatic drainage of the thyroid

Answer 10

Pretracheal, prelaryngeal, paratracheal nodes-> cervical nodes

Question 11

What is the danger in thyroid surgery?

Answer 11

Cutting the recurrent laryngeal nerve-> hoarse voice

Question 12

What is an enlarged thyroid called?

Answer 12

Goitre, may compress trachea, oesophagus and veins