Chapter 57: Thyroid Gland- Anatomy

Question 1

Define the arterial blood supply to the thyroid

Answer 1

Two arteries:

1. Superior thyroid artery (first branch of the external carotid artery)
2. Inferior thyroid artery (branch of the thyrocervical trunk) (IMA artery rare)

Question 2

What is the venous drainage of the thyroid?

Answer 2

• Superior thyroid vein
• Middle thyroid vein
• Inferior thyroid vein

Question 3

Name the thyroid lobe appendage coursing toward the hyoid bone
from around the thyroid isthmus

Answer 3

Pyramidal lobe

Question 4

What percentage of patients have a pyramidal lobe?

Answer 4

≈50%

Question 5

Name the lymph node (LN) group around the pyramidal thyroid lobe.

Answer 5

Delphian LN group

Question 6

What is the thyroid isthmus?

Answer 6

Midline tissue border between the left and right thyroid lobes

Question 7

Which ligament connects the thyroid to the trachea?

Answer 7

Ligament of Berry

Question 8

Which paired nerves must be carefully identified during a
thyroidectomy?

Answer 8

Recurrent laryngeal nerves

• which are found in the tracheoesophageal grooves
• dive behind the cricothyroid muscle
• damage to these nerves paralyzes laryngeal abductors and causes hoarseness if unilateral, and airway obstruction if bilateral

Question 9

What other nerve is at risk during a thyroidectomy and what are the
symptoms?

Answer 9

Superior laryngeal nerve; if damaged, patient will have a deeper and quieter voice (unable to hit high pitches)