Larynx Flashcards
What is the primary function of the larynx?
To act as a valve to prevent airway obstruction and protect the lower airway
What vertebral levels does the larynx span?
C4-C6
What structure marks the inferior end of the larynx?
Inferior margin of cricoid cartilage as it becomes trachea
Which region of the larynx are the vestibular folds in?
supraglottic, transglottic, infraglottic
transglottic.
The supraglottic space extends from the laryngeal inlet to the vestibular folds, but does not include them.
What marks the superior boundary of the infraglottic space?
the inferior margin of the vocal folds (the vocal folds themselves are in the transglottic space)
Where does innervation of the larynx above the vocal folds come from?
internal branch of superior laryngeal nerve off vagus
Where does innervation of the larynx below the vocal folds come from?
inferior laryngeal nerve, a branch of the recurrent laryngeal nerve off vagus
Contraction of the cricothyroid muscles would lead to what change in vocal pitch?
What nerve innervates these muscles?
Contraction of the cricothyroid muscles tilts the thyroid cartilage anteriorly and inferiorly, tightening and lengthening the vocal cords, generating a higher pitch
external branch of superior laryngeal nerve off vagus
What action do the lateral cricoarytenoid muscles have on the vocal cords?
They adduct them
What is the main action of the posterior cricoarytenoid muscles?
abduction of the vocal cords
What muscle is the primary antagonist of the cricothyroid muscles?
the thyroarytenoid muscles. It’s main function is to bring the thyroid cartilage closer to the arytenoids, shortening the vocal cords, generating a deeper pitch.
Also possibly vocalis
What is the rima glottidis?
The space between the opening of the true vocal cords and the arytenoid cartilage
What does the quadrangular membrane connect?
epiglottis to the vestibular ligament
What does the conus elasticus connect?
vocal ligament and the cricoid cartilage
What ligament lines the inferior margin of the true vocal cords? What does it connect to inferiorly
conus elasticus.
Inferiorly connects to cricoid cartilage
What is the rima vestibuli?
space between the vestibular ligaments
What CN predominantly innervates the larynx?
Vagus CN X
Does the transverse arytenoid muscle adduct or abduct the vocal cords?
It spans the gap between the two arytenoids, adducting them when it contracts, closing the rima glottidis
What structures pass between the inferior and middle constrictors to the larynx?
Internal branch of Superior laryngeal n, superior laryngeal a. and v.
What connects the thyroid cartilage to the cricoid along the midline of the body? What is this ligament called as it continues laterally and posteriorly?
median cricothyroid ligament.
Conus elasticus
Where are the laryngeal saccules located with respect to the ventricles? What is their function?
They are the anterosuperior continuation of the laryngeal ventricles. They house many secretory cells that create a fluid to lubricate the vocal cords
What innervates the inlet, vestibule, and ventricle/saccule regions of the larynx?
Internal branch of superior laryngeal nerve of CN X (Vagus)
What innervates the infraglottic space?
Inferior laryngeal nerve of CN X (Vagus)
What is the origin/insertion of the cricothyroid muscle?
origin: anterior and lateral aspects of arch of cricoid cartilage
Insert: inferior margin and inferior horn of thyroid cartilage
