Larynx Flashcards
1
Q
What is the larynx and where is it connected? (3)
A
- 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
2
Q
What are the functions of the larynx? (3)
A
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
3
Q
Laryngeal Skeleton
* Consists of 3 single cartilages:
A
(thyroid, cricoid and epiglottic),
3 paired cartilages (arytenoid, corniculate and cuneiform), extrinsic and intrinsic membranes
4
Q
What are the 1. Thyroid cartilages? (2)
A
o Largest of the cartilages
o Superior border lies opposite C4 vertebra
5
Q
- Thyroid cartilage:
o Laminae:
A
- 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)
6
Q
- Thyroid cartilage:
o Superior thyroid notch:
A
- V-shape superior to the laryngeal prominence where the laminae diverge
7
Q
- Thyroid cartilage:
o Inferior thyroid notch:
A
- Shallow indentation in the middle of the inferior border of the cartilage
8
Q
- Thyroid cartilage:
o Superior and inferior horns:
A
- Superior and inferior projections of the posterior border of each lamina
9
Q
- Thyroid cartilage:
o Median thyroid ligament:
A
- Thick part in the median part of the thyrohyoid membrane
10
Q
- Thyroid cartilage:
o Lateral thyrohyoid ligaments:
A
- Thick parts in the lateral parts of the thyrohyoid membrane
11
Q
- Thyroid cartilage:
o Cricothyroid joints: (2)
A
- 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
12
Q
What is the 2. Cricoid cartilage? (2)
A
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
13
Q
- Cricoid cartilage
Lamina: (3)
A
- Posterior part of cricoid
- Depressions for attachment of posterior
cricoarytenoids - Vertical ridge for attachment to oesophagus
14
Q
- Cricoid cartilage
o Arch:
A
- Anterior part of cricoid
15
Q
- Cricoid cartilage
o Median cricothyroid ligament:
A
- Attachment of the cricoid to the inferior margin of the thyroid cartilage
16
Q
What is the 3. Epiglottis? (5)
A
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
17
Q
o Stalk of the epiglottis:
A
- Attached to the angle formed by the thyroid laminae
18
Q
What are the Extrinsic laryngeal membranes? (4)
A
19
Q
What is the 1. Arytenoid (paired cartilages)? (4)
A
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
20
Q
- Arytenoid
What is the o Vocal process?
A
o Vocal process- provides the posterior attachment for the vocal ligament
21
Q
- Arytenoid
What is the muscular process?
A
o Muscular process- lever to which the posterior and lateral cricoarytenoid muscles are attached
22
Q
What are cricoarytenoid joints?
A
-Located between the bases of the arytenoid cartilages and the superolateral surfaces of the lamina of the cricoid cartilage
23
Q
What do the Cricoarytenoid joints permit? (3)
A
- Permit the arytenoid cartilages
- to slide toward or away from one another
- to tilt anteriorly and posteriorly
- to rotate
24
Q
What is the 2. Corniculate? (2)
A
o Appears as a small nodule in the posterior part of the aryepiglottic fold
o Attaches to the apex of the arytenoid cartilage
25
What is the 3. Cuneiform? (2)
o Appears as a small nodule in the posterior part of the aryepiglottic fold
o Does not directly attach to other cartilages
26
What are Intrinsic laryngeal membranes? (2)
1. Conus elasticus (cricovocal membrane)
2. Quadrangular membrane
27
Fibroelastic membrane of the larynx
1. Conus elasticus (cricovocal membrane):
* Inferior attachment:
o Arch of the cricoid cartilage
28
Fibroelastic membrane of the larynx
1. Conus elasticus (cricovocal membrane):
* Superior attachments: (2)
o Anterior- thyroid cartilage
o Posterior- vocal processes of arytenoids
29
1. Conus elasticus (cricovocal membrane)
* Vocal ligament-
* Vocal ligament- thickened medial part of membrane under the vocal fold
30
1. Conus elasticus (cricovocal membrane)
* Median cricothyroid ligament-
* Median cricothyroid ligament- anterior thickening in the midline of the membrane
31
What is the 2. Quadrangular membrane? (2)
* Runs between the lateral margin of the epiglottis and the anterolateral surface of the arytenoid cartilage
* Attached to the corniculate cartilage
32
* Vestibular ligament-
* Vestibular ligament- thickened free lower margin under the vestibular fold
33
* Vestibular ligament-
o Attached posteriorly to...
o Attached anteriorly to...
o Attached posteriorly to the anterolateral surface of the arytenoid
o Attached anteriorly to the thyroid angle just superior to the vocal ligament
34
Cavity of the larynx:
* Superior aperture: (2)
o Laryngeal inlet
o Opens into the anterior aspect of the pharynx below the posterior tongue
35
Cavity of the larynx:
What are the boundaries of the superior aperture? (3)
- Anteriorly- mucosa covering the superior margin of the epiglottis
- Laterally- aryepiglottic folds
- Posteriorly- interarytenoid notch in the midline
36
Cavity of the larynx:
* Inferior aperture: (3)
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)
37
What are the regions of the cavity? (3)
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
38
* Laryngeal ventricles and saccules:
o Mucosa of the middle cavity bulges ______
o Between the vestibular and _____ ligaments
laterally
vocal
39
What is the o Laryngeal ventricle?
o Laryngeal ventricle- trough shaped space produced by mucosal bulging
40
What is the o Laryngeal saccule?
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
41
What is the * Rima vestibuli? (2)
o Triangular opening between the adjacent vestibular folds
o Apex is anterior and base is formed by posterior wall of laryngeal cavity
42
What is the Rima glottidis? (3)
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)
43
* Both rima glottidis and rima vestibuli can be opened and closed by movement of _______.
cartilages
44
What are the Intrinsic Laryngeal Muscles? (3)
* 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
45
What are the Intrinsic Laryngeal Muscles? (7)
46
Intrinsic Laryngeal Muscles:
Cricothyroid
Origin:
Insertion:
Main Action:
Innervation:
47
Intrinsic Laryngeal Muscles:
Posterior crico-arytenoid
Origin:
Insertion:
Main Action:
Innervation:
- 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.
48
Intrinsic Laryngeal Muscles:
Lateral crico-arytenoid
Origin:
Insertion:
Main Action:
Innervation:
- Superior surface of arch of cricoid
- Vocal process of arytenoid
- Internal rotation of arytenoid (closes rima glottidis)
- Recurrent laryngeal br. of vagus n.
49
Intrinsic Laryngeal Muscles:
Transverse arytenoid
Origin:
Insertion:
Main Action:
Innervation:
- Posterior surface of arytenoid
- Posterior surface of opposite arytenoid
- Adduction of arytenoids
- Recurrent laryngeal br. of vagus n.
50
Intrinsic Laryngeal Muscles:
Oblique arytenoid
Origin:
Insertion:
Main Action:
Innervation:
- Muscular process of arytenoid
- Apex of opposite arytenoid
Aryepiglottic part- extends into aryepiglottic fold
- Sphincter of laryngeal inlet
- Recurrent laryngeal br. of vagus n.
51
Intrinsic Laryngeal Muscles:
Thyroarytenoid
Origin:
Insertion:
Main Action:
Innervation:
- 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.
52
Intrinsic Laryngeal Muscles:
Vocalis
Origin:
Insertion:
Main Action:
Innervation:
- Vocal process of arytenoid
- Ipsilateral vocal ligament
Thyroid angle
- Adjusts tension (minutely) in vocal folds
- Recurrent laryngeal br. of vagus n.
53
Intrinsic Laryngeal Muscles:
* Abductors-
* Adductors-
* Sphinters-
* Tensors-
* Relaxers-
* 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
54
What are the Arteries of the larynx? (2)
* Superior laryngeal artery
* Inferior laryngeal artery
55
What is the Superior laryngeal artery? (4)
o Branch of superior thyroid artery
o Pierces thyrohyoid membrane
o Supplies superior internal surface of larynx
o Accompanied by superior laryngeal nerve
56
What are the veins of the larynx? (2)
* Superior laryngeal vein
o To superior thyroid v. to IJV
* Inferior laryngeal vein
o To inferior thyroid v. to left brachiocephalic v.
57
Lymphatic drainage of the larynx
* Above vocal folds:
o Superior deep cervical lymph nodes
58
Lymphatic drainage of the larynx
* Below vocal folds:
o Pretracheal or paratracheal lymph nodes to inferior deep cervical lymph nodes
59
Innervation of the larynx:
