Anatomy Of The Larynx

Question 1

What is the larynx suspended to?

Answer 1

Hyoid bone by the thyroid cartilage by the thryohyoid membrane

Question 2

What is the larynx?

Answer 2

Dilated, cartilganeous framework, superior most assembly of the upper airways. Acts as a sphincter mainly opened and closed by epiglottis. Starts from Nasopharynx and ends inferiorly as the trachea.

Question 3

Functions of the larynx

Answer 3

Conducts air moving from the nasopharynx to the bronchi and lungs
Important for ventilation of gases of the body
Allows air to be vocalised, allowing speech
Prevents substances from entering airways below via the epiglottis

Question 4

What visceral compartment of the neck is the larynx in and what fascia is it bounded by?

Answer 4

Ensheathed with the infrahyoid muscles to form the pre-tracheal plane of the neck
Bounded by pre-tracheal cervical fascia anteriorly
Bounded by buccopharyngeal fascia posteriorly

Question 5

What are the relations of the larynx?

Answer 5

Laterally: carotid sheaths
Anterolaterally: thyroid gland, infrahyoid muscle
Posteriorly: mucous membranes of the pharynx

Question 6

How does the cartilages, muscles, ligaments, mucosal membranes and hyoid bone relate to the function of the larynx?

Answer 6

Cartilages keep it in rigid form
Muscles act on cartilages to modify its aperture
Ligaments strapping for shape
Mucosal membranes and folds for lining and contribute to its air controlling mechanism
Hyoid bone provides superior attachment for raising or depressing the larynx.

Question 7

What are the cartilages of the larynx?

Answer 7

9 - 3 paired and 3 unpaired
3 paired: arytenoid, corniculate, cuneiform
3 unpaired: thyroid, cricoid, epiglottis

Question 8

Which cartilages are hyaline and which are not?

Answer 8

Epiglottis, thyroid, cricoid and arytenoids are hyaline
Corniculate and cuneiform are smaller, less important and are yellow elastic cartilages

Question 9

Anatomy of the thyroid cartilage

Answer 9

Has the laryngeal prominence (Adam’s apple)
Has superior and inferior thyroid horns allowing it to attach to the hyoid bone above and cricoid cartilage below

Question 10

How is the epiglottis attached to the larynx?

Answer 10

Attached posterior to the thyroid cartilage by the thyroepiglottic ligament.

Question 11

Describe the anatomy of the cricothyroid?

Answer 11

Only cartilage to completely encircle the airways.
2 articular facets on each side:
- superolateral surface for arytenoid cartilage
- lateral surface for medial surface of inferior horn of thyroid cartilage

Question 12

Arytenoid cartilages of larynx

Answer 12

Small paired cartilages. Form part of the larynx to which the vocal cords are attached. They tense the vocal cords and thus aid vocal cord movement. They allow for attachments of muscles, ligaments and mucosal folds.

Question 13

What are the parts to the internal cavity of the larynx?

Answer 13

Supraglottis, glottis, subglottis

Question 14

What is the supraglottis?

Answer 14

Vestibule of the larynx. Boundaries: interior surface of the epiglottis and vestibular folds (false cords)

Question 15

What is the glottis?

Answer 15

Compartment containing the vocal cords/folds.
Glottis = 2 vocal cords and the aperture between them, the rima glottidis

Question 16

How are the vocal cords moved?

Answer 16

By intrinsic muscles of the larynx

Question 17

What is adduction and abduction of vocal cords?

Answer 17

Adduction = movement of cords to the midline to close the glottis
Abduction = movements of the cords away from midline to open the glottis

Question 18

What is the subglottis?

Answer 18

Inferior to the glottis, down to the lower border of cricoid cartilage

Question 19

What innervates the mucosa of the interior of the larynx?

Answer 19

Supraglottic compartment mucosa (including vocal cords) is innervated by the internal laryngeal nerve
Subglottis compartment mucosa is innervated by the recurrent laryngeal nerve

Question 20

What are the false and true vocal cords?

Answer 20

Vestibular fold (false vocal cord)
Vocal ligament and vocalis muscle (true vocal cord)

Question 21

Layers of the vocal cord

Answer 21

Stratified squamous epithelium
Reinke’s space
Vocal ligament
Vocalis muscle

Question 22

Muscles causing Adduction and abduction

Answer 22

Adduction (closed) - lateral cricoarytenoid
Abduction (open) - posterior cricoarytenoid

Question 23

Extrinsic muscles of the larynx

Answer 23

Elevators: suprahyoid muscles
Depressors: infrahyoid muscles
Elevators: longitudinal pharynx muscles (stylopharyngeus, salpingopharyngeus, palatopharyngeus)

Question 24

What do extrinsic muscles of the larynx do?

Answer 24

Move the entire karynx

Question 25

What do intrinsic muscles of the larynx do?

Answer 25

Move the vocal cords

Question 26

What are the intrinsic muscles of the larynx

Answer 26

Cricothryoid, posterior and lateral cricoarytenoid muscles, arytenoid with its transverse and oblique fibres, thyroarytenoid and its thyroepiglottic components

Question 27

What muscles control the laryngeal inlet?

Answer 27

Oblique arytenoid Aryepiglottic muscle

Question 28

Arterial blood supply of the larynx

Answer 28

Superior laryngeal artery (from superior thyroid artery) Inferior laryngeal artery (from inferior thyroid artery)

Question 29

Venous blood supply to the larynx

Answer 29

Superior and inferior laryngeal veins (Arterial and venous blood supply accompany the SLN and RLN)

Question 30

What nerve supplies the intrinsic laryngeal muscles?

Answer 30

Recurrent laryngeal nerve supplies all the intrinsic laryngeal muscles except the cricothyroid, which is supplied by the external branch of the superior laryngeal nerve. Both are branches of the vagus nerve.

Question 31

Where does the recurrent laryngeal branch loop?

Answer 31

Right - under the subclavian artery Left - under the aortic arch It comes back up in the groove between the trachea and oesophagus.

Question 32

What might lesions of the recurrent laryngeal nerve cause?

Answer 32

Hoarseness of voice Recurrent laryngeal nerve palsy

Question 33

What does the superior laryngeal nerve split into?

Answer 33

Internal branch - pierces the thyroidhyoid membrane External branch - deep to superior thyroid artery

Question 34

What do abductors, adductors, tensors and relaxers do?

Answer 34

Abductors increase opening of the rima Adductors reduce opening of rima Tensors increase pitch of voice Relaxers lower pitch of voice