Larynx - Muscles

Question 1

What are the extrinsic muscles of the larynx?

Function?

Answer 1

Consists of the infrahyoid, suprahyoids and stylopharyngeus.

As a general rule, suprahyoids and stylopharyngeus elevates the larynx.

Infrahyoids depress the larynx.

Question 2

What are the different intrinsic muscles of the larynx?

Answer 2

They control the shape of the rima glottidis.

This is the opening between the vocal folds and the arytenoid cartilages.

Posterior cricoarytenoid

Lateral cricoarytenoid

Oblique and transverse arytenoids

Thyroarytenoid

Cricothyroid

Question 3

Innervation of intrinsic muscles?

Answer 3

Branches of the vagus nerve.

Recurrent laryngeal nerve - except cricothyroid.

Cricothyroid - external laryngeal nerve (derived from the superior laryngeal nerve)

Question 4

Posterior cricoarytenoid

Answer 4

Action - abducts vocal cords

Question 5

Lateral cricoarytenoid

Answer 5

Actions - adducts the vocal cords

Modulates tone and volume

Question 6

Transverse and oblique arytenoids

Answer 6

Actions - adducts arytenoid (opening closes/adducts)

Question 7

Cricoarytenoid

Answer 7

Actions - stretches the vocal cords

Modulates tone of voice.

Innervation - external laryngeal nerve

Question 8

Thyroarytenoid

Answer 8

Actions - Relaxes vocal cords