laryngeal anatomy Flashcards
(74 cards)
1
Q
larynx is a specialized tube or cavity sitting above trachea that contains a sphincter
A
larynx
2
Q
supraglottal cavity
A
region above VF
3
Q
subglottal cavity
A
region below VF
4
Q
laryngeal inlet
A
aditus
opening to pharynx
-inlet closed by epiglottis
5
Q
vestibule
A
space between inlet and false vocal folds
6
Q
ventricle
A
space between false vocal folds and true vocal folds
7
Q
structure of larynx: function 4 primary cartilaginous structures
A
for sound production
-and airway production
8
Q
structure of larynx:
1 important cartilage structure
A
epiglottis
-for protecting airway
9
Q
structure of larynx:
1 critical bone
A
hyoid bone
-for anchoring the larynx, protecting airway and moving the larynx up and down
10
Q
cricoid cartilage
A
lower most cartilage sitting atop trachea
- specialized tracheal ring fused together
- resembles a signet ring
- supports and articulates with the thyroid cartilage and arytenoid cartilages
11
Q
narrow anterior aspect of cricoid cartilage
A
called the arch
-provides clearance for the vocal folds
12
Q
posterior lamina of cricoid cartilage
A
provides surface for arytenoid cartilage
13
Q
on lateral surface of cricoid cartilage
A
articulator facets which is the site of cricothyroid joint (synovial)
14
Q
thyroid cartilage
A
largest cartilage fused at anterior midline and open posteriorly
- plates of arch course forward to form a thyroid angle
- oblique line on side of plates is site of muscle attachments
15
Q
thyroid is ____ in males and has a greater angle
A
larger
-sexual dimorphism
16
Q
lower cornu (horns) of thyroid cartilage
A
articulate with cricoid cartilage (joint)
17
Q
superior cornu
or thyroid cartilage
A
attaches to hyoid bone via thyrohyoid ligament (not joint)
18
Q
arytenoid cartilage
A
small paired cartilages with critical function
- rest on top of posterior cricoid
- apex is peak, topped by small corniculate cartilages
- base has concave surface for joint
19
Q
cricoarytenoid joint allows
A
rotation
-rocking and gliding of arytenoid cartilages
20
Q
vocal process
A
- anterior projection of arytenoid cartilage
- attachment for vocal folds
21
Q
muscular processes
A
- lateral projection of arytenoid cartilage
- attachment for muscles that adduct and abduct vocal folds
22
Q
epiglottis
A
large fused leaf-like structure
- arises from inner surface of thyroid cartilage below notch
- connective tissue from sides of epiglottis join to arytenoid cartilages via aryepiglottic folds
- has anterior connection to tongue
- glosso-epiglottic folds
- attaches to hyoid bone via hyoepiglottic ligament
23
Q
epiglottis extends ____ beyond ____ and ___ ____
A
upward, larynx, hyoid bone
24
Q
valleculue
A
formed from juncture of folds and tongue
25
hyoid bone
only bone in body that is not attached to another bone
- floating bone connected by muscles to other structures
- U-shaped with arch anterior - body of hyoid
- has greater horns (cornu) and lesser horns (cornu)
- greater cornu are posterior
- less cornu arise at junction of body and greater cornu - point upwards
26
pull hyoid and larynx downward
infra hyoid muscles
27
pull hyoid and larynx upward and forward
suprahyoids
28
cricothyroid joint
- junction of inferior cornu of thyroid cartilage and lateral arch of cricoid
- synovial joint allowing thyroid cartilage to rotate and move forwards/backwards
- this joint has primary importance in changing length of vocal folds
29
cricoarytenoid joint
- synovial joint with less mobility than cricothyroid
- concave inferior surface of arytenoid rests on convex surface of cricoid
- principal motions are gliding, rocking, and rotation
- rocking actions bring vocal processes together (adduct and abduct)
- rocking can abduct vocal processes away from each other
- gliding actions can pull arytenoids close to each other assisting in closure
30
laryngeal musculature
- each motion described previously allows for closure, opening and length changes of vocal folds
- motions accomplished by muscle contraction
31
two sets of laryngeal muscles
- intrinsic make connections between laryngeal cartilages
| - extrinsic connect laryngeal cartilages to other structures
32
intrinsic muscles
```
cricothyroid
posterior cricoarytenoid
lateral cricoarytenoid
thyroarytenoid
vocalis
interarytenoids: oblique and transverse
```
33
extrinsic muscles
sternothyroid
thyrohyoid
inferior pharyngeal constrictor
34
hyoid muscles
```
suprahyoid
-digastric (anterior and posterior bellies)
geniohyoid
mylohyoid
stylohyoid
genioglossus
infrahyoid
-sternohyoid (sternothyroid & thyrohyoid)
omohyoid
```
35
posterior cricoarytenoid
PCA
- intrinsic laryngeal muscle
- origin: posterior outer surface of cricoid arch
- insertion: muscular process of arytenoid
- fibers course upward and backward
- contraction pulls muscular process posteriorly
- rocks arytenoids away from each other
36
action of PCA
abduct vocal folds
-sole muscle that performs this action
importance during respiration and speech
-stabilizes arytenoid position
37
lateral cricoarytenoid
LCA
origin: superior lateral surface of cricoid
insertion: courses upwards and backwards to muscular process
* antagonist of PCA
38
interarytenoid muscles
IA
- connect the arytenoid cartilages across the midline
- transverse muscle is a single unpaired muscle spanning cartilages
- oblique interarytenoid muscle overlie transverse in X shape
- contraction of these muscles pulls arytenoids together
39
action of LCA
action: rocks muscular process inwards leading to vocal fold adduction
- can also adjust amount of compression between folds (medial compression)
40
action of IA
action: pulls arytenoids together which assists in closing vocal folds
41
vocal fold muscle
-inner or deep portion of vocal folds is occupied by a muscle
-main mass of folds
general name: thyroarytenoid
fan shaped muscle
inner surface of thyroid cart near arch to arytenoid vocal process
-bottom contributes to vocal fold while top diverges towards epiglottis
*forms thyroepiglottis
42
thyroarytenoid
- two separate muscles
- pulls arytenoids and thyroid closer
- result: shortens and relaxes vocal folds acting unopposed (almost NEVER happens)
- the muscle divisions appear to have opposing functions
43
two muscles of thyroarytenoid
-vocalis can tense VF when other intrinsic laryngeal muscles are increasing vocal fold tension and adduction
-thyromuscularis contraction can shorten and relax VFs
together these contribute to pitch control
44
cricothyroid
origin: arch of cricoid
insertion: inferior horn of thyroid - pars oblique
- contraction pulls thyroid towards cricoid
- increase distance between thyroid and arytenoids
- stretches and tenses vocal folds***
45
Vagus Nerve
CN X
- arises from nucleus ambigus in brainstem
- regulates cardiac rhythm
- called the wanderer because it wanders throughout body regulating function of many internal organs
46
emerges from medulla of brainstem
Vagus
- exits skull through jugular foramen
- runs between internal jugular vein and internal carotid giving off branches to pharynx, larynx and constrictors
- continues descending to reach cardiac, pulmonary and esophageal plexuses
47
superior laryngeal nerve
branches off from vagus
- splits inter external and internal branches
- external brach provides motor innervation to CT
- internal branch provides sensory innervation to entire layers excluding inferior surface of vocal folds
48
recurrent laryngeal nerve
RLN
- arises more distally
- loops back upwards to larynx
- right side emerges from vagus within neck and loops around subclavian artey
- left side branches off in chest and loops around aorta
- provides motor innervation to ALL the intrinsic laryngeal muscles
- carries sensory info from inferior surface of vocal folds and upper trachea
49
mucosal membranes and ligaments
external mucosal membrane refers to surface covering oral cavity, nasal cavity, larynx
- intrinsic membranes form the tough connective tissue and ligaments
- includes connective tissue connecting laryngeal cartilages
- not skin, but covers the internal passageways in the same way as skin
- essential to keep mucosa hydrated and healthy
- thickened membranes called ligaments even though they are NOT connecting bones
50
quadrangular membrane
paired membrane joined anteriorly
connects lateral margins of epiglottis to thyroid, corniculate and arytenoids
-fibers curve and descend around to posterior cartilages
-joins up with conus elasticus
superior lateral margins form thickened aryepiglottic folds
inferior portion forms ventricular ligaments overlying ventricular fold
51
conus elasticus
inferior portion
- connects thyroid, arytenoid, and cricoid carts
- name refers to cone shaped upper trachea ending at VFs
- forms anterior cricothyroid ligaments and lateral cricothyroid membrane
* free thickened margins from vocal ligaments*
- vocal ligament forms medial margin of VF
- vocal ligament permits highly specific vibration characteristics to VFs
52
extrinsic membrane
lining surface of larynx and epiglottis is the wet sticky surface called mucosal membrane
- most of if loosely covers underlying structures
- cells forming cover called columner epithelium
53
squamous epithelium & layers
5 specialized layers including surface membrane, vocal ligament, and muscle
only present for VFs
54
layer one
protective membranous layer that also retains moisture
- thin layers of cells called squamous epithelium
0. 1 mm
55
layer two
superficial lamina propria (SLP)
- tough stretchy elastic fibers
- tolerates extensive stretching
56
layer three
intermediate lamina propina of ILP
1-2mm
-tough stretchy tissue intermixed with SLP
-fibers run in AP direction so are cross-layered
-combination of directions increases strength
57
layer four
deep lamina propria or DLP
1-2mm
-tough collagen supportive fibers that resist stretching
58
layer five
muscular layer composed of thyroarytenoid
| -forms bulk of VF
59
extrinsic muscles/hyoid muscles
muscles move larynx up or down or stiffen its position
one attachment to laryngeal cartilages and to another structure
-sternohyoid
-thyrohyoid
-thyropharyngeus
-other muscles attach to hyoid bone but effectively move larynx
60
**coordinated synergistic function to stabilize or move larynx
- intrinsic muscles act at same time as extrinsic
- extrinsic groups broadly affect laryngeal position and provide stability
- intrinsics are producing fine changes in VF adduction
- muscle groups do NOT work against each other in normal function
61
thyrohyoid
INFRAHYOID
origin: thyroid cartilage
insertion: hyoid bone
innervation: ansa cervicalis
function: brings hyoid and thyroid closer
- elevates larynx when hyoid fixed
- depressed hyoid when larynx fixed
62
inferior pharyngeal constrictor
origin: thyroid lamina (external)
insertion: posterior pharyngeal raphe
innervation: Vagus
functon: constricts pharynx and elevates larynx
AKA thyropharyngeus
63
sternothyroid
INFRAHYOID
origin: manubrium
- insertion: oblique line of thyroid cartilage
innervation: CN XI and C1 & C2
function: depresses or fixates thyroid cartilage and larynx
64
extrinsic laryngeal muscles
thyrohyoid
inferior pharyngeal constrictor (thyropharyngeus)
sternothyroid
65
sternohyoid
INFRAHYOID
origin: manubrium
insertion: hyoid
innervation: ansa cervicalis
- together ST and SH can stabilize larynx in medial or depressed position
66
omohyoid
infrahyoid
origin:
superior: hyoid
inferior: scapula
insertion:
superior: inferior belly by intermediate tendon
inferior: superior belly
innervation: ansa cervicalis
function: contraction of superior belly pulls hyoid down
67
stylohyoid
suprahyoid
origin: styloid process of temporal bone
insertion: hyoid bone
innervation: CN VII facial nerve
function: elevates and retracts hyoid and larynx
68
digastric muscle
suprahyoid
origin: temporal bone & mandible
insertion: hyoid bone
innervation: CN VII facial nerve
function: depress mandible but elevate hyoid bone and base of tongue
69
mylohyoid
suprahyoid
origin: mandible
insertion: hyoid bone
innervation: CN V trigeminal nerve
function: pulls hyoid up and forward when mouth fixed
70
geniohyoid
suprahyoid
origin: mandible
insertion: hyoid
innervation: CN XII hypoglossal nerve
function: pull hyoid forward and up
71
hyoglossus
suprahyoid
origin: hyoid bone
insertion: tongue
innervation: CN XII hypoglossal nerve
function: elevates hyoid or pulls tongue back
72
genioglossus
suprahyoid
origin: hyoid bone
insertion: tongue
innervation: CN XII hypoglossal nerve
function: elevate and protrude tongue which pulls hyoid and larynx up and forward
73
VF function
protect airway during aspiration
- open during breathing and closed during swallowing
- coughing out foreign particles
- distinct and separate reflex actions
* vibrate to produce sound
74
cells covering medial portion of vocal folds, ventricular folds and parts of the epiglottis
stratified squamous epithelium
| -these cells are tightly bound to underlying tissue
