Session 11 - The Larynx

Question 1

What does the larynx connect?

Answer 1

The oropharynx to the trachea

Question 2

What does the larynx contain?

Answer 2

The voice box

Question 3

Where does the larynx extend to and from?

Answer 3

Laryngeal inlet (communicates with laryngopharynx) to the level of the inferior border of the cricoid cartilage, at which point it is ocntinous with trachea.

Question 4

Give three functions of the larynx

Answer 4

• Protective sphincter – Open during respiration, closed during swallowing
• Required for effective cough reflex
• Phonation – Vibration of vocal cords as air flows through the narrowed glottis in expiration

Question 5

What does articulation require?

Answer 5

Lips, tongue, pharynx and larynx

Question 6

What does resonance require?

Answer 6

Larynx, pharynx, oral and nasal cavities and sinuses

Question 7

What is the overall structure of the larynx?

Answer 7

Hyoid bone and 9 cartilages

Question 8

What are the cartilages of the larynx?

Answer 8

o	3 Unpaired Cartilages
	Epiglottis
	Thyroid Cartilage
	Cricoid Cartilage
o	1 important set of Paired Cartilages
	Arytenoid Cartilage(s)
o	2 other sets of Paired Cartilages
	Corniculate Cartilage(s)
	Cuneiform Cartilage(s)

Question 9

What is the epiglottis?

Answer 9

Fibrocartilage

Question 10

What is epiglottis attached to and from?

Answer 10

By ligaments to back of bhyoid bone and thyroid cartilage

Question 11

Where the thyroid cartilage located?

Answer 11

C4 level

Question 12

What is the use of the location of the thyroid cartilage

Answer 12

C4 is point of bifurcation of common carotid and the level of the carotid body

Question 13

What is the structure of the thyroid cartilage?

Answer 13

Two large lamina

2 horns

Question 14

What are the two horns of the thyroid cartilage connected to respectively?

Answer 14

 Superior Thyroid Horns  Ligament  Hyoid Bone

 Inferior Thyroid Horn  Synovial Joint with Cricoid

Question 15

What is thyroid cartilage suspended by?

Answer 15

Thyrohyoid membrane

Question 16

What is the shape of the cricoid cartilage?

Answer 16

Signet ring shape

Question 17

What is the anatomical significance of cricoid cartilage?

Answer 17

Surface marking for C6 level (carotid pulse)

Question 18

What are the arytenoid cartilages used for?

Answer 18

Vocal cord movement

Question 19

What is anterior and what is lateral to the arytenoid cartilage?

Answer 19

o Anterior – Vocal process

o Lateral – Muscular process

Question 20

What is the cricovocal membrane?

Answer 20

Made up of elastic fibres

Upper free border is the vocal ligament

Question 21

What are the three spaces of the laryngeal cavity?

Answer 21

Supraglottic space
Glottis
Subglottic space

Question 22

What is the supraglottic space?

Answer 22

Laryngeal inlet -> Vestibular folds (false vocal cords)

Question 23

What is the glottis?

Answer 23

Vocal cords and rima glottis (space between vocal cords)

Question 24

What is the subglottic space

Answer 24

Below vocal cords -> lower border of cricoid cartilage

Question 25

What are the extrinsic muscles of the larynx and what is there function?

Answer 25

o Infrahyoid muscles  Depress larynx o Suprahyoid muscles  Elevate larynx

Question 26

What are the intrinsic muscles of the larynx and what is there function?

Answer 26

o Vocal folds  Open and close glottis o Aryepiglottic folds  Help to close the laryngeal inlet

Question 27

What supplies the intrinsic muscles?

Answer 27

Recurrent laryngeal nerve, except for the cricothyroid which is supplied by external laryngeal nerve

Question 28

What are the layers of the vocal cords?

Answer 28

o Stratified Squamous Epithelium o Vocal (cricothyroid) Ligament o Vocalis Muscle

Question 29

Why do vocal cords look pearly white?

Answer 29

Mucosa firmly adhered to vocal ligament and has no sub mucosa.

Question 30

Give two positives of the firmly adhered mucosa of vocal ligament

Answer 30

No oedema during infection | Delayed spread of carcinoma of vocal cords

Question 31

Give two movements of the vocal cords

Answer 31

Abduction (open) | Adduction (closed

Question 32

What muscle controls true vocal cords?

Answer 32

Posterior cricoarytenoid (only abductor! REMEMBER)

Question 33

What causes abduction of vocal folds?

Answer 33

Posterior cricoarytenoid

Question 34

What causes adduction of vocal cords?

Answer 34

Lateral cricoarytenoid

Question 35

What is the function of the cricothyroid, and why is it odd?

Answer 35

Only intrinsic muscle on the outside, increases vocal cord tension

Question 36

What supplies posterior cricoarytenoid?

Answer 36

Reccurent laryngeal nerve

Question 37

What supplies cricothyroid?

Answer 37

External larygeal nerve

Question 38

What supplies lateral cricoarytenoid?

Answer 38

Recurrent laryngeal

Question 39

What is the innervation of larynx derived from?

Answer 39

Branches of vagus

Question 40

What is superior laryngeal nerve made up of? Give functions

Answer 40

Internal laryngeal nerve - Sensory to larynx above true vocal cord External laryngeal nerve - Motor to cricothyroid

Question 41

What is the recurrent laryngeal nerve? Functins?

Answer 41

Sensory below true vocal cord | Motor to all intrinsic laryngeal muscles

Question 42

What is the path of the right recurrent laryngeal nerve?

Answer 42

 Descends to T2 |  Curves around the Subclavian Artery

Question 43

What is the path of the left recurrent laryngeal nerve?

Answer 43

 Descends to T4 |  Curves around the Arch of the Aorta

Question 44

Where do recurrent laryngeal nerves go?

Answer 44

Up neck, between trachea and oesophagus

Question 45

What is hoarseness of voice caused by?

Answer 45

Intrinsic laryngeal muscle weakness for >3 weeks can be due to recurrent laryngeal nerve palsy and is called "hoarseness"

Question 46

Give 6 causes of hoarseness

Answer 46

``` Infection Overuse of voice GORD Benign nodules on vocal cords Apical lung tumour Bronchial carcinoma Aortic aneurysm ```

Question 47

What do you to assess larynx?

Answer 47

Indirect laryngoscopy Flexible rhinolaryngoscopy Look for abnormalities of larynx and check movements

Question 48

What would an apical lung tumour effect?

Answer 48

Recurrent laryngeal nerve on both sides

Question 49

What is unilateral RLN palsy?

Answer 49

Affected vocal cord does not move Its position is paramedian Cannot narrow glottis during speach

Question 50

What would a bronchial carcinoma effect?

Answer 50

Left recurrent laryngeal nerve palsy (right does not go low enough)

Question 51

Outline blood supply to larynx?

Answer 51

External Carotid Artery  Superior Thyroid Artery  Superior Laryngeal Artery Subclavian Artery  Inferior Thyroid Artery  Inferior Laryngeal Artery

Question 52

Give three causes of laryngeal obstruction

Answer 52

Laryngeal oedema Inhalation of foreign body Tumour

Question 53

Give three causes of laryngeal oedema

Answer 53

Acute epiglottitis Croup Anaphylaxis

Question 54

Why does laryngeal cancer have a good prognosis?

Answer 54

Presents with hoarseness of voice quickly

Question 55

How does you treat laryngeal obstruction?

Answer 55

Emergency cricothyroidotomy (opening into airway through the cricothyroid membrane)

Question 56

Why is thyroid artery significant during thyroidectomy?

Answer 56

Superior thyroid artery ligation may damage superior laryngeal nerve Inferior thyroid artery is ligated, recurrent laryngeal nerve may be damaged

Question 57

ADD IN LARYNGOSCOPY

Answer 57

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