Larynx Flashcards
Over what vertebrae does the larynx relate?
What level are the thyroid and cricoid cartilages?
Posteriorly related to C3-C6 vertebral bodies
Thyroid - C4-C5
Cricoid - C6
What is the vestibule of the larynx?
The cavity superior to the vestibular folds up to the level of the epiglottis
What is the ventricle of the larynx?
The smallest cavity that extends laterally between the vestibular folds and the vocal folds
What is the infraglottic cavity of the larynx?
Cavity extending from vocal folds to inferior border of the cricoid cartilage. (Under that is the trachea)
What is the function of the thyroid + cricoid + arytenoids cartilages?
Change position and tension of the vocal folds to produce variations in voice pitch
What is the function of the epiglottic + 2 cuneiform + 2 corniculate caritlages?
Keep food + foreign bodies out of the larynx
How many laryngeal cartilages are there?
9: three paired, three unpaired
Unpaired: thyroid, cricoid, epiglottis
Paired: arytenoid, corniculate, cuneiform
What fuses to form the laryngeal prominence and what does it make?
The two thyroid lamina fuse anteriorly to make a single thyroid cartilage.
The angle of fusion is sharper in males = more prominent Adam’s apple
What is located posteriorly on the thyroid cartilage? What is their attachment?
Superior horns - attach to lateral thyroid ligaments / all around lamina to thyrohyoid membrane
Inferior horns - attach to cricoid on medial surface of horn
What muscles attach laterally on the thyroid cartilage?
Sternothyroid, thyrohyoid, inferior pharyngeal constrictor
What is the cricothyroid joint and what is its function?
It as the attachment of the cricoid cartilage via its lateral facets to the inferior horn of each thyroid lamina. Functions to allow thyroid cartilage to tilt on cricoid - thyroid cartilage rocks back and forth
What is the cricothyroid ligament?
Ligament attaching the two cartilages via inferior part of thyroid cartilage
What is the shape of the cricoid cartilage and what are its facets?
Singlet ring with thick part direct posteriorly. Has lateral facets for articular with inferior horn of thyroid cartilage, and superior facets for articulation with arytenoids. There is a definitive ridge posteriorly
Where do the arytenoid cartilages sit and what defines their three corners?
They are 3-sided pyramidal cartilages which sit atop the cricoid cartilage and are relatively smooth medially, and pitted laterally.
Apex - oriented superiorly and attaches to aryepiglottic fold, holds corniculate cartilage
Muscular process
Vocal process
What is the muscular process of the arytenoid cartilages?
Side attached to intrinsic laryngeal muscles, normally pointed posteriorly.
What is the vocal process of the arytenoid cartilages?
Side attached to the vocal ligaments, normally pointed anteriorly
What are the corniculate & cuneiform cartilages?
They are paired cartilages in the posterior region of the aryepiglotic folds, with the corniculate being directly atop the arytenoids and the cuneiform being slightly above it.
What is the purpose of the corniculate / cuneiform cartilages?
They help prevent food and foreign bodies from entering the larynx by stabilizing the structural integrity of the aryepiglotic folds whenever they are closed (so trachea can remain closed off)
What is the epiglottic cartilage and its function?
A single thin cartilage shaped like a leaf. Closes the laryngeal inlet (aditus) during swallowing
What are the two ligament attachments of the epiglottic cartilage?
- Thyroepiglottic ligament - inferior attachment, to inside of laryngeal prominence
- Hyoepiglottic ligament - anterior surface attaches upward to the hyoid bone (helps lift larynx during swallowing)
Where do the vocal ligaments extend?
Vocal process of arytenoids to the inside of laryngeal prominence (just below attachment of thyroepiglottic ligament)
What two ligaments extend from cricoid cartilage to vocal ligaments?
Median and lateral cricothyroid ligaments. Median is partially found behind laryngeal prominence
What is the conus elasticus?
The two cricothyroid ligaments + the vocal ligaments