Larynx

Question 1

Where does the larynx sit?

Answer 1

• between the oropharynx and the trachea
• between C3-6
• hangs under hyoid

Question 2

What is the larynx?

Answer 2

membranous fibro-elastic tube suspended between cartilages

Question 3

What are the 3 main functions of the larynx?

Answer 3

• transport of air
• protective sphincter
• phonation (sound)

Question 4

What is the anatomical difference in the larynx of newborns?

Answer 4

slightly higher

Question 5

What are the laryngeal cartilages? (know how to label diagram)

Answer 5

• epiglottis
• thyroid
• cricoid
• arytenoid
• corniculate
• cuneiform

Question 6

What are the attachments of the epiglottis?

Answer 6

• thyroid cartilage by thyroepiglottic ligament

- hyoid bone by hyoepiglottic ligament

Question 7

Describe what makes up the thyroid cartilage

Answer 7

• left and right laminae
• superior horns attached to hyoid bone
• inferior horns attached to cricoid cartilage
• superior thyroid notch
• oblique line for muscle attachment
• thyroid angle which is the laryngeal prominence

Question 8

What does the cricoid thyroid articulate with?

Answer 8

• arytenoids and thyroid
• has sloping shoulder on lamina for arytenoid articulation
• ridge posteriorly for attachment with oesophagus
• depression posteriorly for attachment of crico-arytenoid muscle

Question 9

What does the arytenoid cartilage articulate with?

Answer 9

• artciulates with sloping shoulder of cricoid and lamina
• superiorly articulates with corniculate
• vocal process anteriorly for vocal ligament
• muscular process posterior for posterior and lateral crico-arytenoid muscles
• 2 depressions anteriorly for vestibular ligament and vocalis muscle

Question 10

Where is the thyro-hyoid membrane located?

Answer 10

between upper edges of thyroid laminae and superior horns, and greater horns of hyoid

Question 11

What are the important features of the thyro-hyoid membrane?

Answer 11

• thickened anteriorly and posterior to become median and lateral thyro-hyoid ligaments
• pierced by superior laryngeal vessels and superior laryngeal nerve

Question 12

What are the orders of the membranes from superficial to deep?

Answer 12

laryngeal mucus membrane then fibro-elastic membrane then cartilaginous skeleton

Question 13

What separates the fibro-elastic membrane and what is it divided into?

Answer 13

• fibro-elastic membranes separated by laryngeal ventricle
• superiorly is the quadrangular membrane
• inferiorly is conus elasticus

Question 14

What does the quadrangular membrane cover and what are the edges?

Answer 14

• between lateral aspects of epiglottis, arytenoid and corniculate cartilages
• edges: aryepiglottic fold and vestibular fold

Question 15

What structures form the vestibular fold?

Answer 15

vestibular ligament and mucous membrane

Question 16

What is the clinical significance of the median cricothyroid ligament?

Answer 16

site of emergency access to airway (tracheotomy)

Question 17

What are the 2 parts of the conus elasticus?

Answer 17

• cricovocal membrane

- median cricothyroid ligament

Question 18

What is the function of the vocal/vestibular cord?

Answer 18

• speech
• coughing/sneezing
• raising the intra-abdominal pressure

Question 19

What is contained within the laryngeal cavity?

Answer 19

• vesibule: between laryngeal inlet and vestibular folds
• laryngeal ventricle: recess between vestibuar and vocal folds leading to the saccule
• infraglottic cavity: between vocal folds and trachea

Question 20

What does the saccule do?

Answer 20

lubricates the vocal folds

Question 21

What is the boundary the laryngeal inlet?

Answer 21

aryepiglottic folds

Question 22

What is the rima glottis?

Answer 22

opening between the vocal cords and muscular processes of the arytenoid

Question 23

What are the functions of the muscles of the larynx?

Answer 23

controls the position of the larynx to:

• alter laryngeal diameter to allow passage of air only
• control airflow for speech
• raise intra-abdominal pressure

Question 24

What are the extrinsic laryngeal muscles?

Answer 24

• suprahyoid

- infrahyoid

Question 25

What are the functions of the extrinsic laryngeal muscles?

Answer 25

- arrange the position of the larynx | - facilitate closing of laryngeal inlet

Question 26

What are the functions of the intrinsic muscles?

Answer 26

- adjust length/tension of vocal ligaments - open and close rima glottis - control inner dimensions of vestibule - facilitate closing of laryngeal inlet

Question 27

Where are the intrinsic laryngeal muscles?

Answer 27

extend between laryngeal cartilages

Question 28

What extrinsic laryngeal muscles elevate the pharynx?

Answer 28

- salpingopharyngeus - palatopharyngeus - stylopharyngeus

Question 29

What extrinsic laryngeal muscles elevate the larynx?

Answer 29

- stylohyoid - mylohyoid - geniohyoid - thyrohyoid - digastric

Question 30

What extrinsic laryngeal muscles depress the larynx?

Answer 30

- sternothyroid - thyrohyoid - stylohyoid

Question 31

What laryngeal muscles close the laryngeal inlet?

Answer 31

- salpingopharyngeus - palatopharyngeus - stylopharyngeus - stylohyoid - aryepiglottic muscle (purse string) - thyro-epiglottic muscle (superior fibres)

Question 32

Describe how the laryngeal inlet opens

Answer 32

- larynx descends by elastic recoil | - hypoepiglottic ligament

Question 33

What muscle opens the vocal folds/rima glottis?

Answer 33

posterior crico-arytenoid muscle

Question 34

What muscles close the vocal folds/rima glottis?

Answer 34

- inferior fibres of thyro-arytenoid - lateral crico-arytenoid - transverse arytenoid

Question 35

What lengthens the vocal folds?

Answer 35

- rocking of the thyroid cartilage backwards and forwards at cricothyroid joint - cricothyroid muscles lengthens it

Question 36

What muscle increases tension of vocal folds to raise pitch of voice?

Answer 36

vocalis muscle (part of thyro-arytenoid)

Question 37

What shape is the rima glottis from quiet to forced inspiration?

Answer 37

it goes from triangular to rhomboid

Question 38

What can be seen during a laryngoscopy of phonation?

Answer 38

- vocal folds adduct - air forced through vocal folds causes vibration - cord length and tension altered

Question 39

What can be seen during a laryngoscopy of effort closure?

Answer 39

- vocal and vestibular folds adduct | - airway closed by lateral crico-arytenoid and transverse arytenoid muscles in valsalva maneover

Question 40

Describe what happens during swallowing

Answer 40

- laryngeal elevation - laryngeal inlet closes by epiglottis - after larynx descends and epiglottis springs back hyoepiglottic ligament

Question 41

Describe the arterial supply of the larynx

Answer 41

- superior laryngeal a (from superior thyroid a) | - inferior laryngeal a (from inferior thyroid a)

Question 42

Describe venous drainage of larynx

Answer 42

- superior laryngeal v (from superior thyroid v from IJV) - inferior laryngeal v (from inferior thyroid v from BCV) - inferior thyroid veins at risk during tracheostomy

Question 43

What is the lymphatic drainage of the larynx?

Answer 43

- above vocal cord: superior deep cervical lymph nodes - below vocal cord: * prelaryngeal, pretracheal * inferior deep cervical * supraclavicular

Question 44

Describe the neural supply of the larynx

Answer 44

- superior laryngeal nerve: * internal branch: sensation of larynx down to above vocal folds * external branch: cricothyroid muscle - inferior laryngeal nerve (from recurrent larymgeal nerve from vagus) - recurrent laryngeal nerve: * all intrinsic muscles of larynx (except cricothyroid) * sensation to vocal cords and larynx below