Larynx

Question 1

3 functions of the larynx

Answer 1

– Transport of air
– Protective sphincter
– Phonation

Question 2

where is the larynx

Answer 2

Lies between the levels of ~C3- C6 vertebrae
Mobile
Slightly higher in newborns and
infants

Question 3

EPIGLOTTIS

Answer 3

Attached to the thyroid cartilage by the thyroepiglottic ligament
Attached to the hyoid bone by the hyoepiglottic ligament

Question 4

what makes up the thyroid cartilage

Answer 4

Left and right laminae
 Superior and inferior horns
• Superior horns attached to the hyoid
• Inferior horns articulate with the cricoid cartilage
 Superior thyroid notch
 Thyroid angle  laryngeal
prominence (Adam’s apple)
The oblique line, for muscle attachment

Question 5

CRICOID CARTILAGE

Answer 5

Shape of a signet ring with the lamina posteriorly
Articulates with the arytenoids and the thyroid
Note the “sloping shoulder” on the lamina for arytenoid articulation

Question 6

ARYTENOID CARTILAGE

Answer 6

Articulates with the sloping shoulders of the cricoid lamina and, superiorly, the corniculate cartilage

Question 7

Vocal process

Answer 7

Anteriorly, for attachment of the vocal

ligament

Question 8

Muscular process:

Answer 8

posteriorly for the attachment of posterior and lateral crico-arytenoid muscles

Question 9

THYRO-HYOID MEMBRANE

Answer 9

Extends between the upper edges of the thyroid laminae and superior horns and the body and greater horns of the hyoid
It is thickened anteriorly and posteriorly as the median and lateral thyro-hyoid ligaments

Pierced by superior laryngeal vessels and superior laryngeal nerve (internal branch)

Question 10

FIBRO-ELASTIC MEMBRANE

Answer 10

• Elastic connective tissue underneath the laryngeal mucous membrane stretches between laryngeal cartilages and form fibro-elastic membranes
• Fibro-elastic membranes are separated from each other by laryngeal ventricle
  • Superiorly quadrangular membrane• Inferiorly conus elasticus

Question 11

QUADRANGULAR MEMBRANE

Answer 11

Layer of submucosa
Extends between lateral aspects of the epiglottis, arytenoid and corniculate cartilages.
Edges: aryepiglottic fold, vestibular ligament (fold

Question 12

what makes up the vestibular fold

Answer 12

the ligament and the mucous membrane

Question 13

CONUS ELASTICUS

Answer 13

Also called cricovocal membrane
Blends anteriorly with the median cricothyroid ligament
- The median cricothyroid ligament is the site of emergency access to the airway (tracheotomy)

Question 14

VOCAL CORD

Answer 14

• Vocal cord controls laryngeal diameter for:
  − Speech
  − Coughing/sneezing
  − Raising the intra-abdominal pressure
• Lined with stratified squamous epithelium
  Muscles within and adjacent to the vocal folds narrow or widen the opening between them (rima glottis or glottidis), or alter their tension
  Vestibular cord (false vocal cord)

Question 15

LARYNGEAL CAVITY

Answer 15

1. The vestibule: between the laryngeal inlet and the vestibular folds
2. The laryngeal ventricle: Recess between the vestibular and vocal folds
   − Leads to the saccule, which provides lubricating mucus for the vocal folds.
3. The infraglottic cavity: between the vocal folds and the trachea

Question 16

Laryngeal inlet

Answer 16

bound by the aryepiglottic folds

Question 17

Rima glottis

Answer 17

is the opening between the vocal cords and muscular processes of the arytenoid

Question 18

role of the muscles in the larynx

Answer 18

Its position is controlled by muscles, which, in turn
– alter laryngeal diameters to allow the passage of air only
– control airflow for speech
– raise intra-abdominal pressure

Question 19

Extrinsic muscles laryngeal muscles

Answer 19

• Suprahyoid and infrahyoid muscles
• Arrange the position of the larynx as a whole
• Facilitate closing of the laryngeal inlet

Question 20

intrinsic muscles laryngeal muscles

Answer 20

• Extend between laryngeal cartilages
• Adjust the length or tension of the vocal ligaments
• Open and close the rimaglottis
• Control the inner dimensions of the vestibule
• Facilitate closing of the laryngeal inlet

Question 21

• Elevators of pharynx

Answer 21

• Salpingopharyngeus
• Palatopharyngeus
• Stylopharyngeus

Question 22

Elevators of larynx

Answer 22

• Stylohyoid
• Mylohyoid
• Geniohyoid
• Thyrohyoid
• Digastric

Question 23

Depressors of larynx:

Answer 23

• Sternothyroid • Thyrohyoid

* Sternohyoid

Question 24

INTRINSIC LARYNGEAL MUSCLES roles

Answer 24

1. Open/close the laryngeal inlet (aryepiglottic folds)
2. Open/close the rima glottis (and rima vestibuli) - arytenoid gliding and rotation
3. Lengthen the vocal folds - “rocking” at cricothyroid joints

Question 25

1. Close the laryngeal inlet

Answer 25

Elevation of the larynx and pharynx by extrinsic muscles from skull to larynx and pharynx - Salpingopharyngeus - Palatopharyngeus - Stylopharyngeus - Stylohyoid Ary-epiglottic muscle acts like a “purse-string” Superior fibers of thyro- arytenoid muscle (a.k.a. thyro-epiglottic muscle)

Question 26

open the laryngeal inlet

Answer 26

- Descent of larynx (and pharynx) by elastic recoil | - (Hyoepiglottic ligament)

Question 27

Open vocal folds or rima glottis

Answer 27

Posterior crico-arytenoid muscle | - the only muscle that opens the rima glottis

Question 28

Close vocal folds or rima glottis

Answer 28

- Inferior fibres of thyro-arytenoid - Lateral crico-arytenoid - Transverse arytenoid

Question 29

Lengthen the vocal foldsalter the tension

Answer 29

- The thyroid cartilage may be rocked forwards and backwards at the cricothyroid joint. - Crico-thyroid muscles lengthen, hence increase the tension of the vocal folds

Question 30

Alter the tension of vocal folds

Answer 30

``` Vocalis muscle (part of Thyro-arytenoid muscle) change the tension of the vocal ligaments - Increasing tension raises the pitch of the voice, while decreasing tension lowers it ```

Question 31

LARYNGOSCOPY

Answer 31

- Vocal folds are adducted - Air forced through vocal folds causes vibration - Cord length and tension are altered by cricothyroid, thyro- arytenoid and vocalis muscles - Vocal and vestibular folds are adducted - he airway is closed by lateral crico-arytenoid and transverse arytenoid such as the Valsalva manoeuvre

Question 32

SWALLOWING

Answer 32

During swallowing: − Laryngeal elevation − Closure of the laryngeal inlet by epiglottis As the larynx descends after swallowing the epiglottis springs back by hyoepiglottic ligament

Question 33

ARTERIAL SUPPLY

Answer 33

Superior laryngeal a. from Superior thyroid artery Inferior laryngeal a. from Inferior thyroid artery

Question 34

VENOUS DRAINAGE

Answer 34

Superior laryngeal v. to superior thyroid v. to jugular internal v. Inferior laryngeal v. to inferior thyroid v. to brachiocephalic v.

Question 35

what's at risk during a tracheostomy

Answer 35

The inferior thyroid veins

Question 36

LYMPHATIC DRAINAGE

Answer 36

Above vocal cord to superior deep cervical lymph nodes Below vocal cord to Prelaryngeal, pretracheal, inferior deep cervical and supraclavicular lymph nodes No lymphatic connection between vocal cords

Question 37

NEURAL SUPPLY

Answer 37

The superior laryngeal nerve, a branch of vagus – Internal branch (internal laryngeal nerve): • Sensation of the larynx down to just above the vocal folds • Accompanied by the superior laryngeal artery – External branch (external laryngeal nerve): • Supplies Cricothyroid muscle - Vagus recurrent laryngeal nerve inferior laryngeal nerve is accompanied by the inferior laryngeal artery - The recurrent laryngeal nerve supplies – all the intrinsic muscles of the larynx except cricothyroid – sensation to the vocal cords and larynx below