Anatomy of the Larynx

Question 1

What is the larynx?
Where is it?

Answer 1

• Cartilaginous structure anterior to
laryngopharynx
• Connects pharynx to trachea
• At the level of C3 - C6

Question 2

What are the functions of the larynx?

Answer 2

Functions:
1. Acts as a sphincter, separating the lower respiratory system from the alimentary system
2. Voice production

Question 3

Describe the laryngeal skeleton?

Answer 3

.
Consists of 9 cartilages joined by membranes and ligaments
• Three single cartilages:
1. Thyroid
2. Cricoid
3. Epiglottis
• Three paired cartilages:
1. Arytenoid
2. Corniculate
3. Cuneiform

Question 4

Describe the thyroid cartilage?

Answer 4

• Largest
• Two plate-like Laminae fuse to form laryngeal prominence
• has superior thyroid notch (adam’s apple)
• Superior horns attach to the hyoid bone by thyrohyoid membrane
• Inferior horn attaches to cricoid cartilge

Question 5

Describe the cricoid cartilage?

Answer 5

• Shaped like a signet ring (complete ring)
• The posterior part forms a lamina while the anterior part forms an arch
• Attaches the thyroid cartilage by median cricothyroid ligament and the trachea by cricotracheal ligament

Question 6

Describe the epiglottis cartilage (elastic)?

Answer 6

• forms the anterior superior wall and margin of larynx inlet.
• Attaches to thyroid cartilage by thyroepiglottic ligament.

Question 7

Describe the arytenoid cartilages?

Answer 7

Pairs of three sided pyramids
Articulate with superior border of the cricoid cartilage lamina

Question 8

Describe the corniculate and cuneiform cartilages?

Answer 8

• Small nodules in the posterior part of the aryepiglottic folds.

Question 9

What are the functions of vocal folds (true)?

Answer 9

1. Control sound production
2. Act as inspiratory sphincter

Question 10

Each vocal cord comprises of?

Answer 10

Each vocal fold has:
1 A vocal ligament - medial free edge of the lateral cricothyroid ligament (conus elasticus)
2. A vocalis (vocal) muscle - medial part of the thyroarytenoid muscle

Question 11

The glottis (vocal apparatus) comprises of?

Answer 11

1. Vocal folds and processes
2. The rima glottidis (aperture
   between vocal folds)

Question 12

Changes in the pitch of voice occurs due to variation in?

Answer 12

due to variation in:
1. tension and length of the vocal folds
2. width of the rima glottidis
3. intensity of expiry effort

Question 13

Describe vestibular folds (false)?

Answer 13

Consists of two thick folds of mucous membrane
• Extend between the thyroid and the arytenoid cartilages
1. Rima vestibule - space lateral to vestibular folds
2. Ventricle of the larynx - lateral identation between the vocal and vestibular folds

Question 14

What is the hyoepiglotic ligament?

Answer 14

Attaches the epiglottis to the hyoid bone.

Question 15

What is the thyrohyoid ligament?

Answer 15

• Extends from thyroid cartilage to medial surface of the hyoid bone

Question 16

Describe the laryngeal cavity and folds?

Answer 16

• Divided into three parts:
  1. Vestibule - superior to the vestibular folds
  2. The ventricle (laryngeal sinus) - between the vestibular and vocal folds
  3. Infraglottic cavity - from the vocal folds to the inferior of the cricoid cartilages

Question 17

The laryngeal muscles are divided into?

Answer 17

1. Extrinsic muscles
2. Intrinsic muscles

Question 18

Name extrinsic laryngeal muscles and their functions?

Answer 18

1. infrahyoid muscles - depresses hyoid bone and larynx
2. Suprahyoid muscles - elevate hyoid bond and larynx

Question 19

Name intrinsic laryngeal muscles and and their functions?

Answer 19

1. Principal adductors
   - lateral cricoarytenoid muscle
   - transverse arytenoid muscles
2. Abductors
   posterior cricoarytenoid muscles
   Note: adductors and abductors move the vocal folds to open and close the rima glottidis
3. Sphincters
   - Lateral cricooarytenoids (transverse and oblique)
4. Tensors:
   - cricothyroids
5. Relaxers:
   - thyroiarytenoid muscle .
6. Vocalis muscles

Question 20

State the vasculature and lymph drainage of the larynx?

Answer 20

1. Superior laryngeal artery - branches of superior thyroid arteries
2. Inferior laryngeal artery - branches of inferior thyroid arteries

Veins: accompany arteries:
1. Superior laryngeal vein
2. Inferior laryngeal vein

Lymph vessels:
> Superior deep cervical lymph nodes
> pretracheal or paratracheal lymph nodes
> inferior deep cervical lymph nodes

Question 21

State nerves to the larynx?

Answer 21

1. Superior laryngeal nerve
   branches into:
   i. Internal laryngeal nerve
   - sensory of the larynx
   ii. External laryngeal nerve
   - motor to the cricothyroid muscle
2. Inferior laryngeal nerve
   - continuation of recurrent laryngeal nerve
   - motor
   - supply most muscles of the larynx

Question 22

State consequences of fractures to the laryngeal skeleton?

Answer 22

• Submucous hemorrhage and edema
• Respiratory obstruction
• Hoarseness of the voice

Question 23

What is a laryngoscopy?

Answer 23

Procedure used to examine the interior of the larynx

Question 24

What is laryngitis?

Answer 24

Inflammation of the mucous membrane of the larynx

Question 25

What is laryngeal obstruction (choking)?

Answer 25

• Caused by Aspiration of Foreign Bodies

Question 26

What is the valsalva maneuver?

Answer 26

Any forced expiration effort against a closed airway

Question 27

What is a laryngotomy?

Answer 27

Operative opening of the larynx

Question 28

Describe the consequences of injury to the laryngeal nerves?

Answer 28

Cause paralysis of vocal folds
- hoarseness of voice

Question 29

Describe the ages changes of the larynx?

Answer 29

Grows steadily 3 - 12 years - no sex differences
At puberty: in males larynx cavity enlarges, vocal folds lengthen