AP02 - Larynx

Question 1

What forms the skeleton of the larynx? What muscles move them?

Answer 1

Hyaline and elastic cartilages, they form articulations with each other.
Moved by intrinsic and extrinsic laryngeal muscles

Question 2

Action of the cricothyroid muscle?

Answer 2

1. Rotates thyroid cartilage anteriorly and inferiorly at cricothyroid joint to draw it closer to the cricoid cartilage
2. Tense the vocal ligaments by elongating them, increasing vocal pitch

Question 3

Innervation of cricothyroid muscle?

Answer 3

Vagus nerve (CNX) - external branch of superior laryngeal nerve

Question 4

Action of posterior cricoarytenoid muscle?

Answer 4

1. ABducts the arytenoid cartilage and vocal folds to open rima glottidis
2. Laterally/ externally rotates the arytenoid catilage

Question 5

Which muscle is the only muscle that can open the rima glottidis?

Answer 5

Posterior cricoarytenoid muscle

Question 6

Innervation of posterior cricoarytenoid muscle?

Answer 6

Vagus nerve - recurrent laryngeal branch

Question 7

Action of lateral cricoarytenoid muscle?

Answer 7

1. ADducts the vocal folds to close the rima glottidis

2. Medially/ internally rotates the arytenoid cartilage

Question 8

Innervation of lateral cricoarytenoid muscle?

Answer 8

Vagus nerve - recurrent laryngeal branch

Question 9

Action of transverse arytenoid?

Answer 9

ADducts the arytenoid cartilages

Question 10

Innervation of transverse arytenoid muscle?

Answer 10

Vagus nerve - recurrent laryngeal branch

Question 11

Action of oblique arytenoid muscle?

Answer 11

Narrows the laryngeal inlet- acts as weak sphincter

Question 12

Innervation of oblique arytenoid muscle?

Answer 12

Vagus nerve - recurrent laryngeal branch

Question 13

Action of thyroarytenoid muscle?

Answer 13

1. Narrows laryngeal inlet and vestibule
2. Pulls the arytenoid cartilages anteriorly to relax the vocal ligament
3. Medically rotates the arytenoid artilages to help close the rima glottidis

Question 14

Innervation of thyroarytenoid muscle?

Answer 14

Vagus nerve - recurrent laryngeal branch

Question 15

Action of vocalis?

Answer 15

1. Alter the tension of the vocal ligament - relaxes posterior part of vocal ligament while maintaining tension on anterior part
   [Sometimes classed as part of the thyroarytenoid muscle]

Question 16

Innervation of vocalis?

Answer 16

Vagus nerve - recurrent laryngeal branch

Question 17

What are the muscles of the larynx?

Answer 17

1. Cricothyroid
2. Posterior cricoarytenoid
3. Lateral cricoarytenoid
4. Transverse arytenoid
5. Oblique arytenoid
6. Vocalis
7. Thyroarytenoid

Question 18

What happens to the rima glottidis, rima vestibuli, vestibule and laryngeal inlet during swallowing?

Answer 18

Rima glottidis, rima vestibuli and vestibule are closed.

Laryngeal inlet is narrowed

Question 19

What happens to the epiglottis during swallowing?

Answer 19

Epiglottis swings downwards towards the arytenoid cartilages (narrows laryngeal inlet)

Question 20

What is the rima glottidis?

Answer 20

The opening between the true vocal cords and the arytenoid cartilages of the larynx

Question 21

What are the 3 paired cartilages that make up the larynx walls?

Answer 21

1. Arytenoid
2. Corniculate
3. Cuneiform

Question 22

What are the 3 unpaired cartilages that make up the larynx walls?

Answer 22

1. Cricoid
2. Thyroid
3. Epiglottis

Question 23

Where is the larynx located? (which vertebral level)

Answer 23

Anterior neck at C3-C6