Muscles of the larynx + pharynx Flashcards
What is the role of the Thyroarytenoid muscles?
Pull the arytenoids closer to thyroid cartilage.
What change occurs when the arytenoids are pulled closer to the thyroid cartilage?
Thickness + length of vocal folds
= thicker + shorter
= lower pitch
What is the role of the Vocalis muscles, and where are they located?
Vocalis - makes finer pitch adjustments by adjusting vocal fold thickness
Located on the thyroarytenoids
Which laryngeal muscle pair is the only abductor of the vocal folds?
Posterior Cricoarytenoids
What is the rima glottidis?
The space between the vocal cords also known as the glottis.
Which Cricoarytenoid pair rotates the arytenoids internally?
What does this result in?
Lateral
Adduction
Which Cricoarytenoid pair rotates the arytenoids outwardly?
What does this result in?
Posterior
Abduction
If the arytenoids rotate outwardly, what happens?
Vocal folds open
What is the name for the muscles that connect the arytenoids?
Interarytenoids
When the Interarytenoids contract, do they open or close the vocal folds?
Close
Which branch of the vagus nerve provides both sensory innervation to the laryngeal mucosa and motor innervation to the cricothyroid muscle?
Superior Laryngeal Nerve
If the Superior Laryngeal Nerve is damaged which functions may be impacted.
Loss of sensation
Loss of motor innervation to cricothyroid - reduced vocal fold movement
If sensation to the larynx is lost, what activities will be reduced or lost?
Gag/cough reflex
Swallow initiation
Damage to the Recurrent Laryngeal Nerve usually happens unilaterally, ipsilaterally or bilaterally?
Uni
If the Recurrent Laryngeal Nerve is damaged which muscles lose their functions?
All but the cricothyroid and interarytenoids.
(Inter = bilateral innervation so are weakened)
Which two laryngeal muscles oppose one another?
Cricoarytenoids
The Stylopharyngeus is innervated by which CN?
Glossopharyngeal
How many muscles of the pharynx are there?
6
3 Longitudinal
3 Circular
Name all the Circular/Interior pharyngeal muscles:
Medial
Superior
Inferior
Name all the Longitudinal/External pharyngeal muscles:
Styloppharyngeus
Salpingopharyngeus
Cricopharyngeus
Which Longitudinal muscle is innervated by CN 9 instead of 10?
Stylopharyngeus
If the Recurrent Laryngeal Nerve is damaged, why do the vocal folds tense?
The Superior Laryngeal Nerve is still active, so cricothyroid is still being innervated, but not opposed.
Can the Interarytenoids still adduct the vocal folds even if the Recurrent Laryngeal Nerve is damaged?
Yes
Interarytenoids = bilateral = some adduction
