Sievert: Larynx, Nasal Cavity Flashcards
What is the opening of the larynx called?
the aditus
What happens around the laryngeal opening during swallowing?
the larynx gets pulled up
the tongue pushes back
the epiglottis gets pushed down closer to the posterior aspect of the cricoid cartilage
What is the area from the aditus to the vestibular folds?
the vestibule
What is the area between the true and false vocal folds?
the ventricle
What is the area below the true vocal folds?
the infraglottic cavity
*extends to the inferior end of the cricoid cartilage (below that is the tracheal rings)
What causes vibration of the true vocal folds? Is it the muscles?
Vibration of true vocal folds is not fascilitated by the muscles, but by air moving past the vocal folds. The air movement over them is what causes their vibration, while the muscles just determine the rate at which they vibrate.
What is this?
Large cartilagenous mass that is open posteriorly (filled with mucous linings)
thyroid cartilage
What are these?
Triangular shaped cartilages on top of the cricoid cartilages
arytenoids
What are two portions of the arytenoids? What is significant about each?
muscular process *has muscles attached to it that adduct or abduct the true vocal cords
vocal process *has a ligament to anterior border of the thyroid cartilage
What is this?
Most inferior ring of cartilage; forms a complete ring; taller posteriorly and shorter anteriorly
cricoid cartilage
What is the membrane between the cricoid and thyroid cartilages? What is significant about this membrane?
cricothyroid membrane; it has an elastic core and can enlarge or decrease in size depending on the position of the thyroid cartilage relative to the cricoid cartilage
What is this?
synovial joint that allows for tipping of the thyroid cartilage relative to the cricoid cartilage
cricothyroid joint
What axis of movement occurs at the cricothyroid joint?
transverse axis *allows the two cartilages to rock forward or backwards
There is a ligamentous structure coming off of the vocal process. What happens to this ligament if you rock the thyroid cartilage anteriorly? What happens to the ligament if you rock the thyroid cartilage posteriorly?
If you rock the thyroid cartilage forward, the ligament will get tight. If you rock it backwards, the ligament will get lax. *Allows for increase or decrease in tension of the vocal ligaments.
So what are the two synovial joints of the laryngeal cartilages?
- one between the cricoid and thyroid cartilages
2. one between the arytenoids and the cricoid
What is unique about the joint between the arytenoids and the cricoid cartilage?
it is a multiaxial joint; allows for rotation around the vertical axis and gliding movements medially and laterally *movement on both of these axes allows for adduction and abduction of the arytenoids
What does the thyrohyoid membrane connect? What passes through the hole in this membrane?!
hyoid bone and thyroid cartilage; internal branch of superior laryngeal nerve passes through
So what are the two extrinsic membranes of the larynx?
thyrohyoid membrane
cricothyroid membrane
What’s this?
Mucus lined membrane between epiglottis and artyenoid cartilages; helps keep food from going into the aditus (there are muscles associated w this membrane that act like a purse-string on the aditus and narrow it down)
quadrangular membrane
What does the superior free edge of the conus elasticus form? What does the inferior free edge of the quadrangular membrane form? What is the space between the two free edges?
true vocal fold and vocal ligament; false vocal fold; ventricle
What is this?
the vocal fold plus the slit (rima glottidis) between the two folds)
glottis
Synovial joints
Articulation between the inferior cornu of thyroid and the cricoid cartilage
Movement occurs around transverse axis
cricothyroid joint
Only laryngeal muscle not innervated by the recurrent
laryngeal nerve
cricothyroid muscle
What does the cricothyroid muscle do?
Rocker! When it contracts, it pulls the anterior border of the cricoid cartilage toward the thyroid cartilage, causing the arytenoids to move posteriorly and puts tension on the vocal ligaments which adducts them (brings them closer together!
Muscles that open the vocal ligaments (abduction) would have to be attached to what process of the arytenoid?
muscular process
What are the two movements of the arytenoids at the cricoarytenoid joint?
rotation on vertical axis
gliding movements on horizontal plane
*both of these actions abduct and adduct
What is the major ABDUCTOR of the vocal ligaments?
posterior cricoarytenoid
Where does the posterior cricoarytenoid come off of? Where does it attach? What does it do?
comes off the musclar process and attaches to the posterior midline of the cricoid cartilage; abducts
What does the lateral cricoarytenoid do? Where does it pass in relation to the cricoid cartilage?
ADDUCTS; passes anterior to cricoid cartilage
What does the transverse arytenoid muscle do? What does it pass between?
adducts; between the arytenoid cartilages
What does the oblique arytenoid muscle do?
pursestrings the aditus
What other muscle aids in pursestringing the aditus?
thyroepiglottic
What does the thyroarytenoid do? Where does it run?
from arytenoids to thyroid cartilage just under the true vocal folds; shortens vocal ligaments
What muscle is this?
Most important in helping to determine the pitch of your voice – selectively loosens or contracts small segments of the vocal ligament
vocalis
*ex: if your vocal ligament is very long, you’ll get a lower pitch, but when vocal ligament is shorter, higher pitch
Do you ever completely close off the larynx?
no, not even when muscles are purse-stringing
What muscles add and abduct on the vertical axis?
lateral (add) and posterior (ab) cricoarytenoid muscles