10 - Larynx

Question 1

What are the functions of the larynx?

Answer 1

Protective sphincter for lower resp tract against food
Speech
Breathing - allows air exchange from lungs

Question 2

What is the larynx?

Answer 2

Below hyoid bone, begins at laryngeal inlet extends to lower cricoid cartilage where it becomes the trachea

Question 3

What is the route inspired air takes?

Answer 3

Oral cavity/ Nasopharynx
Oropharynx
Larynx
Trachea

Question 4

What is the route food takes?

Answer 4

Oral cavity
Oropharynx
Laryngopharynx
Oesophagus

Question 5

Describe the framework of the larynx

Answer 5

Thyroid membrane connected to hyoid bone (sup) and thyroid cartilage (inf)
Thyroid cartilage connected to cricoid cartilage by synovial joint and cricothyroid membrane
Thyroid cartilage connects to epiglottis by ligaments
Cricoid cartilage has arytenoid cartilages sitting on top

Question 6

When is the cricothyroid membrane used to reach airway?

Answer 6

Patient can’t be intubated or ventilated - swelling to vocal cords, emergency

Question 7

What is the function of the quadrangular membrane?

Answer 7

Joins epiglottis ti aryetenoid cartilage

Question 8

What are aryepiglottic folds?

Answer 8

Quadrangular membrane covered by mucosa, form beginning of larynx
Sides of folds form piriform fossa

Question 9

What is the vestibular ligament?

Answer 9

Free border of quadrangular membrane, false vocal cord

Question 10

What is the vocal ligament?

Answer 10

Upper free borders of cricothyroid ligament, forming vocal cord

Question 11

Where is the larynx in relation to the laryngopharynx?

Answer 11

Anterior

Question 12

What are the divisions of the larynx?

Answer 12

Supraglottis - larynx above vocal cords
Glottis - true vocal cords and gap between them
Infraglottis - Below vocal cords to lower cricoid cartilage

Question 13

What type of epithelium lines the larynx?

Answer 13

Pseudostratified ciliated columnra epithelium

Question 14

What type of epithelium lines the vocal cords?

Answer 14

Stratified squamous epithelium - better deals with abrasive force of constant friction

Question 15

What is the function of the laryngeal muscles?

Answer 15

Alter size and shape of inlet
Alter tension in vocal cords
Which combined, closes larynx during swallowing, protecting respiratory tract
Opens larynx, allowing movement of air
Control movements of vocal cords in phonation and in cough reflex

Question 16

What muscle abducts (opens) vocal cords?

Answer 16

Posterior cricoarytenoid

Question 17

What determines the position and thus size of aperture of vocal cords?

Answer 17

Position of arytenoids on cricoid cartilage

Question 18

Describe the innervation of the muscles of the larynx

Answer 18

All by recurrent laryngeal nerve of vagus X

Except cricothyroid - superior laryngeal X

Question 19

Describe the movement of the vocal cords during breathing?

Answer 19

Vocal cords abduct

Glottis wide open

Question 20

Describe the movement of the vocal cords during phonation

Answer 20

Vocal cords adduct

Expired air forced through closely adducted vocal cords to vibrate a column of air

Question 21

Describe the movement of the vocal cords during a cough

Answer 21

Vocal cords powerfully adducted
Intrathoracic pressure builds
Vocal cords suddenly abducted

Question 22

How is vocal pitch altered?

Answer 22

Bilateral contraction of cricothyroid muscle increases length and tension of vocal cords, making them taut, high pitch sounds
Low pitched, vocal cords relaxed

Question 23

What is the effect of superior laryngeal nerve damage?

Answer 23

Hoarse voice, especially when attempting high pitch sounds

Question 24

How is the airway protected during swallowing?

Answer 24

Contraction of aryepiglottic muscles narrows laryngeal inlet and pulls down epiglottis
Elevation of larynx by pharyngeal and suprahyoid muscles
Vocal cords close

Question 25

What causes vocal cord palsies?

Answer 25

Inferior thyroid artery injury
Aortic arch aneurysm
Cancer of apex of lung

Question 26

What are the consequences of a unilateral vocal cord palsy?

Answer 26

Hoarse voice

Ineffective couggh

Question 27

What are the consequences of a bilateral vocal cord palsy?

Answer 27

Narrow glottis, significant airway obstruction

Question 28

What conditions causing potentially threatening swelling of larynx?

Answer 28

Croup
Epiglottitis
Laryngeal oedema