ENT Otolaryngologic Anatomy 4

Question 1

Which is the only intrinsic laryngeal muscle that abducts the vocal folds?

Accepted Answer

Posterior cricoarytenoid

Answer

The posterior cricoarytenoid rotates the arytenoids outward to open the glottis, and losing it on both sides can block the airway.

Question 2

The cricothyroid muscle is supplied by which nerve?

Accepted Answer

External branch of the superior laryngeal nerve

Answer

The cricothyroid tenses the vocal folds and is the only intrinsic laryngeal muscle supplied by the external branch of the superior laryngeal nerve.

Question 3

A Zenker's diverticulum herniates through which area?

Accepted Answer

Killian's dehiscence between the thyropharyngeus and cricopharyngeus

Answer

A Zenker's diverticulum pushes through Killian's dehiscence, the weak spot between the oblique thyropharyngeus and the horizontal cricopharyngeus.

Question 4

Around which structure does the left recurrent laryngeal nerve loop?

Accepted Answer

Aortic arch at the ligamentum arteriosum

Answer

The left recurrent laryngeal nerve hooks under the aortic arch next to the ligamentum arteriosum, so its course is longer than the right one's.

Question 5

A nonrecurrent laryngeal nerve is most often found with which anatomic variant?

Accepted Answer

Aberrant right subclavian artery (arteria lusoria)

Answer

A right nonrecurrent laryngeal nerve occurs in about 0.5-1% of people and almost always goes with a retroesophageal aberrant right subclavian artery.

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