Clinical Anatomy of Larynx

Question 1

The larynx is located within which layer of fascia in the neck?

Answer 1

Pretracheal fascia deep to the investing fascia

Question 2

The larynx is located between what vertebral levels?

Answer 2

C4-C6

Question 3

What is the anatomical cause of pulmonary aspiration?

Answer 3

Respiratory and GI tracts have a common pathway in the oro- and laryngopharynx so food can be aspirated into the respiratory tract easily

Question 4

List preventative features for pulmonary aspiration

Answer 4

Increase of larynx towards oesophagus

Epiglottis moves posteriorly to close the laryngeal inlet

Question 5

What aspiratory response does the body initiate during pulmonary aspiration?

Answer 5

Cough reflex

Question 6

What forms the skeleton of the laryngeal cartilages?

Answer 6

Hyoid bone

Question 7

List the cartilage structures found in the larynx, from superior to inferior

Answer 7

Epiglottis
Thyroid (anterior)
(Cricothyroid joint)
Cricoid (anterior)
Arytenoid (posterior)

Question 8

What tissue makes up spaces between the laryngeal cartilages?

Answer 8

Thyrohyoid membrane

Question 9

Describe the structure of the cricoid

Answer 9

Anterior = arch
Posterior = lamina

Question 10

What is the function of cricoid pressure on the oesophagus?

Answer 10

Closes oesophagus whilst larynx remains open, allowing ventilation but preventing aspiration

Question 11

List the structures of the larynx above the laryngeal ventricle

Answer 11

Laryngeal inlet (aditus)
Laryngeal vestibule

Question 12

List the structures of the larynx below the laryngeal ventricle

Answer 12

Infraglottic cavity:
False vocal cord (vestibular fold)
True vocal cord (vocal fold)

Question 13

The laryngoscope should be placed into what laryngeal structure?

Answer 13

Vallecula (space between epiglottis and tongue)

Question 14

Outline the two types of vocal cords and their connections to other laryngeal structures

Answer 14

TRUE: arytenoid - thyroid
FALSE: arytenoid - epiglottis

Question 15

Which structure is located between the cricoid and the vocal ligament?

Answer 15

Conus ellasticus

Question 16

Which structure is located between vestibular ligament and epiglottis?

Answer 16

Quadrangular membrane

Question 17

What is the ‘rima glottidis’?

Answer 17

Space between true vocal cords

Question 18

Outline the innervation of the intrinsic muscles of the larynx

Answer 18

CNX

Question 19

Tension of the vocal cords has what effect on the sound produced by the mouth?

Answer 19

Increases pitch

Question 20

Relaxation of the vocal cords has what effect on the sound produced by the mouth?

Answer 20

Reduces pitch

Question 21

Adduction of the vocal cords has what effect on the sound produced by the mouth?

Answer 21

Reduces volume

Question 22

Abduction of the vocal cords has what effect on the sound produced by the mouth?

Answer 22

Increases volume

Question 23

Which muscle(s) controls tension of the vocal cords? What are it’s connections? What effect does this have on the sound produced by the mouth?

Answer 23

Cricothyroid
Anterolateral cricoid to inferior horn of thyroid
Increases pitch

Question 24

Which muscle(s) controls relaxation of the vocal cords? What are it’s connections? What effect does this have on the sound produced by the mouth?

Answer 24

Thyroarytenoid
Posterior thyroid to anterior arytenoid cartilage
Reduces pitch

Question 25

Which muscle(s) controls adduction of the vocal cords? What are it's connections? What effect does this have on the sound produced by the mouth?

Answer 25

``` Lateral cricoarytenoid Muscular process of arytenoid to anterior cricoid Arytenoid Arytenoid cartilage to cricoid cartilage Reduces volume ```

Question 26

Which muscle(s) controls tension of the vocal cords? What are it's connections? What effect does this have on the sound produced by the mouth?

Answer 26

Posterior cricoarytenoid Posterior cricoid to muscular process of arytenoid Increases volume

Question 27

What process needs to occur for phonation to happen?

Answer 27

Subglottal pressure must be reached via contraction of inspiratory and expiratory muscles, causing air to cross the vocal cords and create a vibration

Question 28

How is sound resonance created by the laryngeal muscles?

Answer 28

Laryngeal buzz is amplified by pharynx, oral and nasal cavities

Question 29

How is oral articulation created by the laryngeal muscles?

Answer 29

Soft palate tenses (CNV3) and CNX innervation is increased which closes off nasopharynx, sound is interrupted by the tongue and teeth/ lips to produce words

Question 30

How is nasal articulation created by the laryngeal muscles?

Answer 30

Soft palate tenses (CNV3) and CNX innervation is reduced which closes off oropharynx, 1 of 3 sounds (m,n,ing) is produced depending on the position of the tongue, teeth and lips

Question 31

List the most common methods used in patients who are learning to speak again

Answer 31

Tracheoesophageal puncture Oesophageal speech Electrolarynx

Question 32

Outline the innervation of the laryngeal mucosa above the fold

Answer 32

CNX --> Superior laryngeal nerve --> Internal laryngeal nerve

Question 33

Outline the innervation of the laryngeal mucosa below the fold

Answer 33

CNX in the mediastinum --> Recurrent laryngeal nerve --> Inferior laryngeal nerve

Question 34

Outline the innervation of the intrinsic muscles of the larynx

Answer 34

Inferior laryngeal nerve (except cricothyroid: external laryngeal nerve)

Question 35

What is 'Galen's anastomosis'?

Answer 35

Connecting branch between inferior laryngeal nerve and internal laryngeal nerve

Question 36

How are the pharyngeal muscles supplied by CNX tested?

Answer 36

Ask the patient to swallow a small sip of water | Look for spluttering

Question 37

How are the laryngeal muscles supplied by CNX tested?

Answer 37

Ask the patient to speak | Look for hoarseness

Question 38

How are the other muscles (not of the pharynx and larynx) supplied by CNX tested?

Answer 38

Ask the patient to cough | Is it normal and powerful?