Larynx

Question 1

What is the larynx and where is it connected? (3)

Answer 1

• Composed of 9 cartilages connected by ligaments and membranes and contains vocal folds
• Located in the anterior neck at the level of the bodies of C3-C6 vertebrae
• Connects the inferior part of the pharynx with the trachea

Question 2

What are the functions of the larynx? (3)

Answer 2

o Valve routing air and food
- Upward and forward movements facilitate the closing of the laryngeal inlet and opening of the oesophagus
o Voice production
- Vocal ligament and intrinsic muscles
o Airway patency
- Serves as the sphincter of the lower respiratory tract

Question 3

Laryngeal Skeleton
* Consists of 3 single cartilages:

Answer 3

(thyroid, cricoid and epiglottic),
3 paired cartilages (arytenoid, corniculate and cuneiform), extrinsic and intrinsic membranes

Question 4

What are the 1. Thyroid cartilages? (2)

Answer 4

o Largest of the cartilages
o Superior border lies opposite C4 vertebra

Question 5

1. Thyroid cartilage:
   o Laminae:

Answer 5

• Two plate-like regions of the inferior 2/3 of the cartilage that fuse anteriorly in the median plane to form the laryngeal prominence (Adam’s apple)

Question 6

1. Thyroid cartilage:
   o Superior thyroid notch:

Answer 6

• V-shape superior to the laryngeal prominence where the laminae diverge

Question 7

1. Thyroid cartilage:
   o Inferior thyroid notch:

Answer 7

• Shallow indentation in the middle of the inferior border of the cartilage

Question 8

1. Thyroid cartilage:
   o Superior and inferior horns:

Answer 8

• Superior and inferior projections of the posterior border of each lamina

Question 9

1. Thyroid cartilage:
   o Median thyroid ligament:

Answer 9

• Thick part in the median part of the thyrohyoid membrane

Question 10

1. Thyroid cartilage:
   o Lateral thyrohyoid ligaments:

Answer 10

• Thick parts in the lateral parts of the thyrohyoid membrane

Question 11

1. Thyroid cartilage:
   o Cricothyroid joints: (2)

Answer 11

• Articulation between the inferior horns of the thyroid cartilage and the lateral surfaces of the cricoid cartilage
• Movements- rotation and gliding of the thyroid cartilage ® change in length of vocal folds

Question 12

What is the 2. Cricoid cartilage? (2)

Answer 12

o Smaller than thyroid cartilage but thicker and stronger
o Cricoid is the only complete ring of cartilage to encircle any part of the airway

Question 13

2. Cricoid cartilage
   Lamina: (3)

Answer 13

• Posterior part of cricoid
• Depressions for attachment of posterior
  cricoarytenoids
• Vertical ridge for attachment to oesophagus

Question 14

2. Cricoid cartilage
   o Arch:

Answer 14

• Anterior part of cricoid

Question 15

2. Cricoid cartilage
   o Median cricothyroid ligament:

Answer 15

• Attachment of the cricoid to the inferior margin of the thyroid cartilage

Question 16

What is the 3. Epiglottis? (5)

Answer 16

o Consists of elastic cartilage for flexibility
o Heart-shaped and covered with mucous membrane
o Located posterior to the root of the tongue and the hyoid and anterior to the laryngeal inlet
o Forms the superior part of the anterior wall and the superior margin of the inlet
o Has a broad, free superior end

Question 17

o Stalk of the epiglottis:

Answer 17

• Attached to the angle formed by the thyroid laminae

Question 18

What are the Extrinsic laryngeal membranes? (4)

Answer 18

Question 19

What is the 1. Arytenoid (paired cartilages)? (4)

Answer 19

o Paired, 3-sided pyramidal cartilages
o Articulate with the lateral parts of the superior border of the cricoid cartilage lamina
o Apex superiorly, vocal process anteriorly and muscular process laterally
o Apex- bears the corniculate cartilage and attaches to the aryepiglottic fold

Question 20

1. Arytenoid
   What is the o Vocal process?

Answer 20

o Vocal process- provides the posterior attachment for the vocal ligament

Question 21

1. Arytenoid
   What is the muscular process?

Answer 21

o Muscular process- lever to which the posterior and lateral cricoarytenoid muscles are attached

Question 22

What are cricoarytenoid joints?

Answer 22

-Located between the bases of the arytenoid cartilages and the superolateral surfaces of the lamina of the cricoid cartilage

Question 23

What do the Cricoarytenoid joints permit? (3)

Answer 23

• Permit the arytenoid cartilages
• to slide toward or away from one another
• to tilt anteriorly and posteriorly
• to rotate

Question 24

What is the 2. Corniculate? (2)

Answer 24

o Appears as a small nodule in the posterior part of the aryepiglottic fold
o Attaches to the apex of the arytenoid cartilage

Question 25

What is the 3. Cuneiform? (2)

Answer 25

o Appears as a small nodule in the posterior part of the aryepiglottic fold o Does not directly attach to other cartilages

Question 26

What are Intrinsic laryngeal membranes? (2)

Answer 26

1. Conus elasticus (cricovocal membrane) 2. Quadrangular membrane

Question 27

Fibroelastic membrane of the larynx 1. Conus elasticus (cricovocal membrane): * Inferior attachment:

Answer 27

o Arch of the cricoid cartilage

Question 28

Fibroelastic membrane of the larynx 1. Conus elasticus (cricovocal membrane): * Superior attachments: (2)

Answer 28

o Anterior- thyroid cartilage o Posterior- vocal processes of arytenoids

Question 29

1. Conus elasticus (cricovocal membrane) * Vocal ligament-

Answer 29

* Vocal ligament- thickened medial part of membrane under the vocal fold

Question 30

1. Conus elasticus (cricovocal membrane) * Median cricothyroid ligament-

Answer 30

* Median cricothyroid ligament- anterior thickening in the midline of the membrane

Question 31

What is the 2. Quadrangular membrane? (2)

Answer 31

* Runs between the lateral margin of the epiglottis and the anterolateral surface of the arytenoid cartilage * Attached to the corniculate cartilage

Question 32

* Vestibular ligament-

Answer 32

* Vestibular ligament- thickened free lower margin under the vestibular fold

Question 33

* Vestibular ligament- o Attached posteriorly to... o Attached anteriorly to...

Answer 33

o Attached posteriorly to the anterolateral surface of the arytenoid o Attached anteriorly to the thyroid angle just superior to the vocal ligament

Question 34

Cavity of the larynx: * Superior aperture: (2)

Answer 34

o Laryngeal inlet o Opens into the anterior aspect of the pharynx below the posterior tongue

Question 35

Cavity of the larynx: What are the boundaries of the superior aperture? (3)

Answer 35

- Anteriorly- mucosa covering the superior margin of the epiglottis - Laterally- aryepiglottic folds - Posteriorly- interarytenoid notch in the midline

Question 36

Cavity of the larynx: * Inferior aperture: (3)

Answer 36

o Continuous with the trachea o Completely encircled by the cricoid cartilage o Always open (unlike superior aperture which can be closed by the epiglottis)

Question 37

What are the regions of the cavity? (3)

Answer 37

1. Vestibule o Upper chamber o Between the laryngeal inlet and the vestibular folds (membrane enclosing vestibular ligaments) 2. Middle part o Between the vestibular folds above and vocal folds (membrane enclosing vocal ligaments) below 3. Infraglottic space o Inferior chamber o Between the vocal folds and inferior aperture

Question 38

* Laryngeal ventricles and saccules: o Mucosa of the middle cavity bulges ______ o Between the vestibular and _____ ligaments

Answer 38

laterally vocal

Question 39

What is the o Laryngeal ventricle?

Answer 39

o Laryngeal ventricle- trough shaped space produced by mucosal bulging

Question 40

What is the o Laryngeal saccule?

Answer 40

o Laryngeal saccule- tubular extension of each ventricle - Projects antero-superiorly between vestibular fold and thyroid cartilage - Contains numerous mucous glands to lubricate the vocal folds

Question 41

What is the * Rima vestibuli? (2)

Answer 41

o Triangular opening between the adjacent vestibular folds o Apex is anterior and base is formed by posterior wall of laryngeal cavity

Question 42

What is the Rima glottidis? (3)

Answer 42

o Inferior to the rima vestibuli and narrower o Triangular opening between the adjacent vocal folds o Base of the triangle is formed by interarytenoid fold (mucosa covering interarytenoid notch)

Question 43

* Both rima glottidis and rima vestibuli can be opened and closed by movement of _______.

Answer 43

cartilages

Question 44

What are the Intrinsic Laryngeal Muscles? (3)

Answer 44

* Adjust the tension in the vocal ligaments to open and close the rima glottidis * Control the inner dimensions of the vestibule and close the rima vestibuli * Facilitate closing of the laryngeal inlet

Question 45

What are the Intrinsic Laryngeal Muscles? (7)

Answer 45

Question 46

Intrinsic Laryngeal Muscles: Cricothyroid Origin: Insertion: Main Action: Innervation:

Answer 46

Question 47

Intrinsic Laryngeal Muscles: Posterior crico-arytenoid Origin: Insertion: Main Action: Innervation:

Answer 47

- Posterior surface of lamina of cricoid - Vocal process of arytenoid - Abduction and external rotation of arytenoid (opens rima glottidis) - Recurrent laryngeal br. of vagus n.

Question 48

Intrinsic Laryngeal Muscles: Lateral crico-arytenoid Origin: Insertion: Main Action: Innervation:

Answer 48

- Superior surface of arch of cricoid - Vocal process of arytenoid - Internal rotation of arytenoid (closes rima glottidis) - Recurrent laryngeal br. of vagus n.

Question 49

Intrinsic Laryngeal Muscles: Transverse arytenoid Origin: Insertion: Main Action: Innervation:

Answer 49

- Posterior surface of arytenoid - Posterior surface of opposite arytenoid - Adduction of arytenoids - Recurrent laryngeal br. of vagus n.

Question 50

Intrinsic Laryngeal Muscles: Oblique arytenoid Origin: Insertion: Main Action: Innervation:

Answer 50

- Muscular process of arytenoid - Apex of opposite arytenoid Aryepiglottic part- extends into aryepiglottic fold - Sphincter of laryngeal inlet - Recurrent laryngeal br. of vagus n.

Question 51

Intrinsic Laryngeal Muscles: Thyroarytenoid Origin: Insertion: Main Action: Innervation:

Answer 51

- Thyroid angle and cricothyroid ligament - Anterolateral part of arytenoid Lateral margin of epiglottis - Sphincter of vestibule and laryngeal inlet Relaxes vocal ligament - Recurrent laryngeal br. of vagus n.

Question 52

Intrinsic Laryngeal Muscles: Vocalis Origin: Insertion: Main Action: Innervation:

Answer 52

- Vocal process of arytenoid - Ipsilateral vocal ligament Thyroid angle - Adjusts tension (minutely) in vocal folds - Recurrent laryngeal br. of vagus n.

Question 53

Intrinsic Laryngeal Muscles: * Abductors- * Adductors- * Sphinters- * Tensors- * Relaxers-

Answer 53

* Abductors- posterior crico-arytenoids * Adductors- lateral crico-arytenoids, transverse and oblique arytenoids * Sphinters- adductors and aryepiglottic part of oblique arytenoids * Tensors- cricothyroid muscles * Relaxers- thyroarytenoid muscles

Question 54

What are the Arteries of the larynx? (2)

Answer 54

* Superior laryngeal artery * Inferior laryngeal artery

Question 55

What is the Superior laryngeal artery? (4)

Answer 55

o Branch of superior thyroid artery o Pierces thyrohyoid membrane o Supplies superior internal surface of larynx o Accompanied by superior laryngeal nerve

Question 56

What are the veins of the larynx? (2)

Answer 56

* Superior laryngeal vein o To superior thyroid v. to IJV * Inferior laryngeal vein o To inferior thyroid v. to left brachiocephalic v.

Question 57

Lymphatic drainage of the larynx * Above vocal folds:

Answer 57

o Superior deep cervical lymph nodes

Question 58

Lymphatic drainage of the larynx * Below vocal folds:

Answer 58

o Pretracheal or paratracheal lymph nodes to inferior deep cervical lymph nodes

Question 59

Innervation of the larynx:

Answer 59