Airway anatomy

Question 1

Describe the function of the following muscles: Posterior cricoarytenoids

Answer 1

Pull the posterior end of the arytenoid cartilage together medially resulting in abduction of the vocal cords.

Question 2

Describe the function of the following muscles: lateral cricoarytenoids and transverse arytenoids

Answer 2

They are adductors causing the vocal cords to close.

Question 3

Describe the function of the following muscles: aryepiglottics and thyroepiglottics

Answer 3

They are layngeal sphincters which close the laryngeal inlet during swallowing

Question 4

Describe the function of the following muscles: cricothyroids

Answer 4

Tilt the cricoid cartilage on to the thyroid cartilage causing the cords to tense

Question 5

Describe the function of the following muscles: thyroarytenoids and vocalis

Answer 5

Relaxors of the cords, vocalise is responsible for fine adjustments

Question 6

Describe the nerve supply of the larynx.

Answer 6

Above the vocal cords the sensory supply is from the superior laryngeal nn. This splits into the external and internal laryngeal nn. The external supplies the motor function for the cricothyroid muscle.

Below the cords the sensory nerve supply is from the recurrent laryngeal nn. The recurrent laryngeal nn is he motor supply for all the intrinsic muscles of the larynx other than the cricothyroid.

Question 7

What are the roles of the extrinisic and intrinsic muscles of the larynx?

Answer 7

Extrinsic muscles are attached to the hyoid and move the larynx up and down during swallowing.

Intrinsic muscles open the vocal cords during inspiration, close the cords and laryngeal inlet during swallowing and alter the tension of the cords during phonation.

Question 8

Describe the symptoms of superior laryngeal nn palsy

Answer 8

Superior laryngeal nn palsy: hoarse voice due to loss of function of the cricothyroid muscle (cord tensor). Increased aspiration risk due to loss of sensation above the cords.

Question 9

Describe the symptoms of recurrent laryngeal nn palsy

Answer 9

Unilateral: Hoarse voice as the cord will not be able to abduct so will be in a midpoint, this will also stop the glottis from closing tightly therefore patients cannot generate positive intra-thoracic pressure to cough effectively.

Bilateral: inability for the cords to abduct therefore patient will be in respiratory distress with stridor.

Question 10

What is the widest part of the nasal airway?

Answer 10

Below the inferior turbinate (during nasal intubation the tube is passed along the floor of the nose below the inferior turbinate)

Question 11

Which nerves supply sensation to the tonsils

Answer 11

Branches of the glossopharyngeal, maxillary and mandibular nn

Question 12

Describe the afferent and efferent nn supply of the gag reflex

Answer 12

Afferent (sensory) glossopharyngeal
Efferent (motor) vagus

Question 13

What is the location of the larynx in relation to the c-spine

Answer 13

4th-6th cervical vertebrae

Question 14

The framework of the larynx consists of articulating cartilages, name them?

Answer 14

Thyroid
Cricoid (note complete ring)
Epiglottis

Paired:
Arytenoids
Corniculate
Cuneiform