Larynx

Question 1

What are the functions of the larynx?

Answer 1

Prevent food/fluid entering airway
Ventilation
Cough reflex
Production of sound

Question 2

What is the larynx?

Answer 2

Part of the respiratory system that lies below the hyoid bone

Question 3

What are the borders of the larynx?

Answer 3

Begins at the laryngeal inlet

Continues as the trachea

Question 4

What makes up the larynx?

Answer 4

3 single cartilages

• thyroid
• cricoid
• epiglottis

3 paired cartilages

• arytenoid cartilages
• corniculate cartilages
• cuneiform cartilages

Membranes

• thyrohyoid membrane
• cricothyroid membrane
• cricotracheal membrane
• quadrangular membrane

Question 5

What are the aryepiglottic folds?

Answer 5

Form the margins of the oval inlet - from the epiglottis to arytenoid

Question 6

What is the quadrangular membrane?

Answer 6

Membrane between the aryepiglottic folds and vestibular ligament

Question 7

What is the vestibular ligament?

Answer 7

False vocal cord

Free lower border of quadrangular membrane

Question 8

What is the vocal ligament?

Answer 8

True vocal cord

Upper free border of cricothyroid membrane

Question 9

Where does the larynx lie in relation to the pharynx?

Answer 9

Anterior to the laryngopharynx

Question 10

What are the 3 parts of the larynx?

Answer 10

Supraglottis
Glottis
Infraglottis

Question 11

Where does the supraglottis part lie?

Answer 11

Epiglottis -> vestibular ligament

Question 12

Where does the glottis part lie?

Answer 12

Vestibular ligament -> vocal ligament

Question 13

Where does the infraglottis part lie?

Answer 13

Vocal ligament -> trachea

Question 14

What type of epithelium lines the larynx?

Answer 14

Pseudostratified ciliated columnar epithelium

Question 15

What are the main actions of the laryngeal muscles?

Answer 15

Alter size and shape of inlet
Alter size/position of vocal cords
Close inlet + cords during swallowing

Question 16

What do the intrinsic laryngeal muscles do?

Answer 16

Move cartilages of larynx relative to one another - movement of vocal cords

Question 17

What innervates the laryngeal muscles?

Answer 17

Recurrent laryngeal nerve - branch of CN X

Question 18

What do the vocal cords do during inspiration/expiration?

Answer 18

Abduct

Question 19

What innervates the cricothyroid muscle?

Answer 19

External branch of superior laryngeal nerve - branch of CN X

Question 20

What happens to the vocal cords during a cough?

Answer 20

Vocal cords adducted

Intrathoracic pressure builds

Cords suddenly adducted

Question 21

How is the pitch of vocal sound determined?

Answer 21

Vocal cord tension

Question 22

What muscle controls vocal fold tension?

Answer 22

Cricothyroid muscle

Question 23

What is the action of the cricothyroid muscle?

Answer 23

Tilts thyroid cartilage forward on cricoid increasing tension in vocal cords

Question 24

What happens in the larynx during swallowing?

Answer 24

Contraction of aryepiglottic muscles - narrows laryngeal inlet + pulls down epiglottis

Elevation of larynx - by pharyngeal muscles

Closure of vocal cords

Question 25

What are the branches of the vagus nerve supplying the larynx?

Answer 25

Superior laryngeal Recurrent laryngeal

Question 26

What does the superior laryngeal nerve supply?

Answer 26

Internal branch - sensory to supraglottic region External branch - motor - to cricothroid muscle

Question 27

What does the recurrent laryngeal nerve supply

Answer 27

Sensory to subglottic region Motor to intrinsic muscles

Question 28

What is the route of the recurrent laryngeal nerve?

Answer 28

Arises from vagus Right = loops under subclavian artery Left = loops under arch of aorta Ascends in trachea-oesophageal groove

Question 29

What is a sign of a unilateral vocal cord palsy?

Answer 29

Hoarseness of voice

Question 30

What happens in a unilateral vocal cord palsy?

Answer 30

Paralysed vocal cord assumes a paramedial position Contralateral side compensates

Question 31

What happens in a bilateral vocal cord palsy?

Answer 31

Both vocal cords are paralysed and in paramedian position Narrow glottis

Question 32

Why is a bilateral vocal cord palsy an emergency?

Answer 32

Airway obstruction - requires emergency surgical airway

Question 33

What conditions can effect the larynx?

Answer 33

``` Laryngitis Laryngeal nodules Croup Epiglottitis Laryngeal oedema ```

Question 34

What is laryngitis?

Answer 34

Inflammation of the vocal cords

Question 35

What is croup?

Answer 35

Inflammation of the larynx and trachea due to RSV

Question 36

What are the symptoms of croup?

Answer 36

Barking cough Hoarse voice Stridor

Question 37

What is epiglottitis?

Answer 37

Life-threatening condition where there is inflammation of the epiglottis

Question 38

What are the signs of a patient with a compromised upper airway?

Answer 38

Stridor Raised resp rate Distress Hypoxia