The Larynx

Question 1

What structures does the larynx connect?

Answer 1

The inferior oropharynx with the trachea

Question 2

Where does the larynx extend from and to?

Answer 2

Laryngeal inlet to the level of the inferior border of the cricoid cartilage

Question 3

Function of the larynx?

Answer 3

Guard the air passages, especially during swallowing, where it serves as a sphincter of the lower resp tract

Question 4

What is the laryngeal skeleton made up of?

Answer 4

Hyoid bone

9 cartilages

Question 5

Name the cartilages of the larynx

Answer 5

3 unpaired

• epiglottis
• thyroid
• cricoid

Paired

• arytenoid cartilage
• corniculate cartilage
• cuneiform cartilage

Question 6

What is the epiglottis attached to?

Answer 6

Back of the hyoid bone and thyroid cartilage by ligaments

Question 7

What level is the upper border of the thyroid cartilage at?

Answer 7

C4

Question 8

What important anatomical landmarks are there at the superior border of the thyroid cartilage?

Answer 8

Bifurcation of the common carotid artery

Level of the carotid body

Question 9

What shape is the cricoid cartilage said to be?

Answer 9

Signet ring shaped

Question 10

What vertebral level does the cricoid cartilage mark?

Answer 10

C6

Question 11

What articulates with the two articular facets on either side of the cricoid cartilage?

Answer 11

Inferior horn of thyroid cartilage

Arytenoid cartilage

Question 12

What shape is the arytenoid cartilage said to be?

Answer 12

Pyramid

Question 13

What is on the anterior and lateral sides of the arytenoid cartilage?

Answer 13

Anterior - vocal process

Lateral - muscular process

Question 14

Which cartilage is important for vocal cord ligament?

Answer 14

Arytenoid cartilage

Question 15

Where does the cricovocal ligament/membrane run between?

Answer 15

Deep surface of the angle of the thyroid cartilage to the vocal process of the arytenoid cartilage

Question 16

What are the divisions of the internal larynx?

Features of each division?

Answer 16

Supraglottic space

• laryngeal inlet
• vestibular folds (false vocal cords)

Glottis

• vocal cords
• rima glottis (space between vocal cords)

Subglottic space

Question 17

Which groups can the laryngeal muscles be divided into?

Answer 17

Extrinsic and intrinsic muscles

Question 18

What is the function of the extrinsic muscles of the larynx?

Answer 18

Move the entire larynx

• infrahyoid muscles depress it
• suprahyoid muscles elevate it

Question 19

Function of the intrinsic muscles of the larynx?

Answer 19

Open and close the glottis by acting on the vocal folds

Help to close the laryngeal inlet by acting on the aryepiglottic folds

Question 20

Innervation of the intrinsic muscles?

Answer 20

Recurrent laryngeal nerve

Except for the cricothyroid muscle supplied by the external laryngeal nerve

Question 21

What are the layers of the vocal cords?

Answer 21

Stratified squamous epithelium
Vocal ligament
Vocalis muscle

Question 22

What are the implications of a lack of submucosa of the vocal cords?

Answer 22

Vocal cords look pearly white on laryngoscopy
No oedema during infections
Delayed spread of carcinoma of vocal cords

Question 23

Which muscles carry out abduction of the vocal cords?

Answer 23

Posterior cricoarytenoid

Question 24

Which muscles carry out adduction of the vocal cords?

Answer 24

Lateral cricoarytenoid

Cricothyroid

Question 25

The branches of which cranial nerve is the larynx innervated by?

Answer 25

Branches of the vagus nerve

Question 26

Function of the superior laryngeal nerve in the larynx?

Answer 26

- internal laryngeal nerve - sensory to the larynx above the true vocal cord - external laryngeal nerve - motor to cricothyroid muscle

Question 27

Function of the recurrent laryngeal nerve?

Answer 27

Sensory to below the true vocal cord

Question 28

Which vessels do the right and left recurrent laryngeal nerves loop around?

Answer 28

Right - descends to T2 and loops around subclavian artery Left - descends to T4 and loops around the arch of the aorta

Question 29

What does the recurrent laryngeal nerve run upwards in?

Answer 29

Tracheo-oesophageal groove

Question 30

Causes of hoarse voice?

Answer 30

Recurrent laryngeal nerve palsy - aortic aneurysm - apical lung tumour - bronchial carcinoma (only on left as right doesn't go low enough) Laryngitis (viral or streptococcal) GORD Benign nodules on vocal cords

Question 31

Blood supply to the larynx?

Answer 31

External carotid artery - superior thyroid artery - superior laryngeal artery Subclavian artery - inferior thyroid artery - inferior laryngeal artery

Question 32

Venous drainage of the larynx?

Answer 32

Superior laryngeal vein - superior thyroid vein - internal jugular Inferior laryngeal vein - inferior thyroid vein - left brachiocephalic vein

Question 33

What can an upper airway/laryngeal obstruction be caused by?

Answer 33

Laryngeal oedema -infection - acute epiglottitis, croup, anaphylaxis Inhalation of a foreign body Tumours

Question 34

Where is a cricothyroidotomy performed?

Answer 34

In an emergency situation | Opened through the cricothyroid membrane