Larynx

Question 1

What are the four extrinsic laryngeal ligaments?

Answer 1

Thyrohyoid membrane (Lat. and median thyrohyoid ligaments), cricotracheal membrane, hyoepiglottic, and glossoepiglottic.

Question 2

What level does the thyroid cartilage lie at? What do its superior and inferior horns interact with?

Answer 2

The thyroid cartilage lies at the level of CV4/5. Superior horn is attached to the hyoid by the lat. thyrohyoid ligaments. Inferior horn articulates with the cricoid cartilage.

Question 3

What attaches to the apex, vocal process, and muscular process of the arytenoid?

Answer 3

Apex - attaches to aryepiglottic lig.
Vocal process - attaches to vocal lig.
Muscular process - attaches to lat. and post. cricoarytenoid mm.

Question 4

What are the 4 ligaments associated with the epiglottis?

Answer 4

Hyoepiglottic, aryepiglottic, thyroepiglottic, and glossoepiglottic lig.s

Question 5

What are epiglottic valleculae?

Answer 5

Formed by folds of mucosa overlying the lat. and median epiglottic lig.s

Question 6

What are the attachments of the quadrangular ligament? Describe it specializations (2).

Answer 6

Anteriorly the quadrangular ligament attaches to the thyroid and epiglottis. Posteriorly attaches to the arytenoids. Superior thickening is referred to as the aryepiglottic lig. Inf. thickening is referred to as the vestibular lig.

Question 7

What are the attachments of the cricovocal (conus elasticus) lig? Describe its specializations (3).

Answer 7

Attaches inferiorly to the cricoid and superiorly to the thyroid and arytenoid. Superiorly thickens to form the vocal lig.s. Medially and laterally thickens to form the median and lateral cricothyroid lig.s.

Question 8

Describe the cricothyroid joint

Answer 8

Synovial articulation between the inferior horn of the thyroid and cricoid cartilage. Allows the thyroid to glide forwards and backwards changing the length of the vocal cords.

Question 9

Describe the cricoarytenoid joint

Answer 9

Synovial articulation between the arytenoids and the cricoid cartilage. Allows for the gliding and rotation of the arytenoids on the cricoid cartilage.

Question 10

What are the actions of the cricothyroid m?

Answer 10

Pulls the thyroid cartilage anteriorly causing elongation and tightening of the vocal ligaments.

Question 11

What are the actions of the transverse and oblique arytenoid mm?

Answer 11

Adduct the arytenoids causing approximation of the vocal cords closing the rima glottidis

Question 12

What are the actions of the posterior cricoarytenoid m?

Answer 12

Abducts the vocal ligaments opening the rima glottidis

Question 13

What are the actions of the lateral cricoarytenoid m?

Answer 13

Adducts the vocal ligaments closing the rima glottidis

Question 14

What are the actions of the thyroarytenoid m?

Answer 14

Pulls the thyroid back causing shortening and loosening of the vocal ligaments

Question 15

What are the actions of the vocalis m?

Answer 15

Most internal portion of the thyroarytenoid m. this is able to perform local changes to the tension in the vocal lig.s

Question 16

What provides GVE-P and GVA to the supraglottic region and SVA to the epiglottic valleculae?

Answer 16

Internal laryngeal n.

Question 17

What innervates the laryngeal mm. except for cricothyroid m?

Answer 17

Inferior laryngeal n. External laryngeal n. innervates the cricothyroid m.

Question 18

Describe the mechanism of the cough reflex

Answer 18

Stimulation of the GVA provided by the internal branch of the superior laryngeal n. causes reflexive contraction of the laryngeal mm. and a cough to force air out of the larynx. If the superior laryngeal n. is ever ablated this reflex will be lost.

Question 19

What result will injury to external laryngeal n. have on phonation?

Answer 19

Monotonous voice

Question 20

Where is superior laryngeal n. block administered and why?

Answer 20

Administered in cases of endotracheal tube insertion. Insert the needle halfway between the hyoid bone and thyroid cartilage

Question 21

What provides GVA, GVE-P, and SVE to the infraglottic region?

Answer 21

Inferior laryngeal n.

Question 22

What effect would unilateral and bilateral lacerations of the recurrent laryngeal nn. have on phonation?

Answer 22

Unilateral injury would cause hoarseness. Bilateral injury will cause aphonation.

Question 23

What is the arterial supply to the larynx (3 arteries)?

Answer 23

Superior laryngeal artery - branch of the superior thyroid artery supplies the region above the true folds
Cricothyroid artery - branch of superior thyroid artery supplies the cricothyroid m.
Inferior laryngeal artery - branch of inferior thyroid artery supplies the region below the true folds