Station 4: Larynx Flashcards
What are the major functions of the larynx?
Produces sound
Acts as a conduit of air from the laryngopharynx to the trachea
Closes off the airways during swallowing
What are the 3 paired cartilages of the larynx?
The Arytenoids, Corniculates, Cuneiforms
What are the 3 unpaired cartilages of the larynx?
Epiglottis, Thyroid, Cricoid
What is the aditus? What are its’ boundaries?
Aditus is the inlet to the larynx from the laryngopharynx.
Anteriorly: Free edge of the epiglottis
Laterally: Aryepiglottic folds
Posteriorly: Arytenoid cartilages, corniculate cartilages
What are the names of the subdivisions of the larynx? What are their boundaries?
Supraglottic cavity:
Extends from the aditus (superiorly) to the glottis (between the true vocal folds)
Infraglottic Cavity:
Extends from the glottic (superiorly) to the first tracheal ring at the end of the larynx (C6/7)
What are the names of the cavities 1) above the vestibular folds, 2) between the vestibular folds and the true vocal folds, 3) Below the true vocal folds?
1) Vestibule (of the supraglottic cavity)
2) The ventricle
3) Infraglottic cavity
What is the rima vestibuli?
The space between the vestibular folds (false vocal folds).
What is the Rima glottidis?
Space between the true vocal folds
What is the glottis?
The combination of the rima glottidis and the true vocal folds themselves
What are the true vocal folds attached to?
The arytenoid cartilages (posteriorly) and the thyroid cartilage (anteriorly)
What muscle is the true vocal fold composed of? and what is its epithelium?
Vocalis muscle (thyroarytenoid muscle). Edges of the true vocal folds are stratified squamous epithelium (as they open and close, thus get damaged more)
Which muscle adduct the true vocal folds?
Lateral Cricoarytenoids and Transverse Arytenoids
Which muscles abduct the vocal folds?
Posterior Cricoarytenoids
What function does the vocalis muscle serve?
Adjusts tension on the vocal folds
Lowering and Raising the pharynx - which muscles?
Suprahyoid and Infrahyoid muscles
What are the vocal fold’s resting position?
Abducted, to allow breathing
What does the cricothyroid muscle do?
Tilts thyroid anteriorly
What does the thyroarytenoid muscle do?
Shortens the vocal folds, decreasing tension, and lowering pitch
What does vocalis muscle do?
Limits the vibration of the vocal folds, affecting the pitch of the voice
What muscles help to narrow the laryngeal inlet to prevent food or drink entering the larynx?
Oblique Arytenoid, Aryepiglottic, Thyroepiglottic muscles
Which cranial neve supplies motor and sensory innervation to the larynx?
Which 2 specific branches of this nerve supply the larynx?
Vagus: CN X
The L & R Recurrent Laryngeal Nerves
Superior Laryngeal Nerve
All muscles supplied by the recurrent laryngeal nerve
Except cricothyroid which is innervated by the superior laryngeal nerve
Which nerves, and what areas of the larynx, provide sensory innervation?
Everything above the true vocal fold = superior laryngeal nerve
Everything below the true vocal fold = Recurrent Laryngeal nerve
Why are there two types of epithelia on the epiglottis? What are they?
The inferior portion of the epiglottis is respiratory epithelium.
The superior surface is stratified squamous.
This is because the superior surface comes in contact with swallowed food and liquid, as the epiglottis shuts over the larynx to prevent food entry into the larynx. As such, this surface is prone to abrasion from swallowed substances, thus has adapted a more ‘protective’ stratified squamous epithelium.
What type of gland(s) is present in the lamina propria of the respiratory mucosa?
Mucous secreting acini with serous demilunes
