The Larynx Flashcards
The larynx functions as a compound sphincter that closes the airway during swallowing and during _____ (as in coughing, lifting a heavy weight).
Valsalva’s maneuver
Note: don’t forget about phonation
What bones lies at vertebral lvl 3?
The hyoid bone
Where is the lower border of the larynx?
The cricoid cartilage
What structure can be found immediately below the thyroid gland?
The larynx
Where are the lesser cornua and greater cornua ?
Lesser: laterally
Greater: posteriorly
What ligament runs between the styloid process and the lesser horn of the hyoid?
The stylohyoid ligament
Where are the muscles attached on the hyoid?
Along the surface of the greater horn and body of the hyoid
The ____ membrane connects the hyoid bone to the thyroid cartilage.
Thyrohyoid
What membrane runs from the smooth medial surface of the hyoid bone to attach along
the upper border of the thyroid cartilage.
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The thyrohyoid membrane
What pierces the thyrohyoid membrane supero-laterally?
The superior laryngeal artery and nerve
Below the thyroid notch is the ____ (Adam’s apple) that, due to growth stimulated by testosterone, is more apparent in men than in women. The result is longer vocal cords that vibrate at a lower frequency.
laryngeal prominence
What membrane is below the vocal cords and relatively avascular, allowing it to be incised to provide an emergency airway?
The cricothyroid membrane (called a cricothyrotomy)
A pair of ____ cartilages articulate with the upper postero-lateral borders of the cricoid cartilage
arytenoid
Each arytenoid cartilages has a base, an apex, an anterior ______,
and a lateral muscular process for muscle attachments.
Vocal process
A small detached portion of the apex of the arytenoid cartilage is the?
Corniculate cartilage
The base of the arytenoids form a shallow ball and socket ______ articulation with the upper border of the cricoid.
diarthrodial
Note: it’s called the crico-arytenoid joint
What movement does the crico-arytenoid joint permit?
Allows the arytenoid cartilages to slide toward or away from one another, to tilt anteriorly and posteriorly, and to rotate
What is the crico-arytenoid joint important in?
Tensing, and relaxing the vocal folds
At what joints does movement of the larynx occur?
At the cricoarytenoid and cricothyroid joints.
Each of the paired vocal ligaments (cords) extends from ?
the vocal process of the arytenoid cartilage to the junction of the thyroid cartilages.
Each of the paired vestibular ligaments (cords) courses from the?
anterior surface
of the arytenoid to the base of the epiglottis near the midline and above the vocal
ligament.
What does greater tension of the vocal ligament cause?
Higher pitch voice
What muscle causes a higher pitched voice (tension on the vocal ligaments)
Cricothyroid muscle
What nerve innervates the cricothyroid muscle?
External branch of the superior laryngeal nerve of the vagus
What does paralysis of the cricothyroid muscle result in?
A monotone voice because pitch cannot be varied
What is the opening to the airway?
The rima glottis
What muscle produces actions that oppose those of the cricothyroid muscle?
The thyroarytenoid muscle
Note: it has two belies, an internus and externus
What muscle inserts anteriorly at the anterior commissure of the thyroid cartilage and postero-laterally on the lateral surface of the arytenoid.
The externus thyroarytenoid
What happens when the externus thyroarytenoid contract?
The vocal processes are shortened and there is a slight adduction
What muscle arises from the anterior commissure and inserts onto the vocal process of the arytenoid cartilage.
The internus thyroarytenoid
What happens during contraction of the internus thyroarytenoid muscle?
The vocal processes are shortened and thickened
Note: In isolation, this action serves to lower the resonant frequency (pitch) of the vocal folds.
What muscle is known as the vocalis?
The internus thyroarytenoid
What muscle serves to lower the resonant frequency (pitch) of the vocal folds?
The internus thyroarytenoid
Contraction of the _______ m raises the pitch of the voice, whereas that of the ____ m tends to lower the pitch.
Cricothyroid
vocalis (The internus thyroarytenoid)
What muscle arises from a broad insertion on the posterior face of the cricoid lamina.
The posterior cricoarytenoid
Contraction of the posterior cricoarytenoid displaces the muscular process posteriorly and caudally, while the vocal process moves upward and laterally. What is the result of this?
Abduction of the vocal processes outward (opens the rima glottis)
It can also tense the vocal ligament
What muscle is the only abductor of the vocal folds and is principally responsible for control of the glottic airway.
The posterior cricoarytenoid
What muscle is attached to the anterior part of the muscular process of the arytenoid medially and to the superior border of the cricoid cartilage laterally.
Lateral cricoarytenoid
Contraction of the lateral cricoarytenoid muscle results in movement of the muscular process anterolaterally while simultaneously forcing the vocal process downward and medially. What is the result of this?
Adduction and lengthening of the vocal folds
What muscle is the most powerful doctor of the vocal folds and important component of the Valsalva procedure?
The lateral cricoarytenoid
What is the valsalva procedure?
tightening of the abdominal and thoracic musculature when lifting a heavy object, child birth, defecation, etc.
Rapid and forceful contraction of what muscle (laryngospasm) can occur during endoscopic examination of the vocal cords and can be life threatening?
The lateral cricoarytenoid
The oblique fibers of the interarytenoids continue to the epiglottis as the _____ muscle that courses along the upper border of the quadrangular membrane
ary-epiglotticus muscle
How do the transverse fivers of the interarytenoid muscle rune?
Between the medial surface of the arytenoid cartilages
What happens when the interarytenoid muscles contract?
Arytenoid adduction and narrowing of the rima glottis
How can the interarytenoid muscle achieve whispering?
By opposing the other muscles so that the vocal cords are slight abducted
The anterior surface of the epiglottis is joined to the hyoid by what ligament?
The hyoepiglottic ligament
What creates the vestibular fold?
The fibro-elastic quadrangular membrane between the arytenoid cartilages and the epiglottis
The superior border of the vestibular fold covers the aryepiglottic ligament and muscle to create a?
Aryepiglottic fold that covers the cuneiform and corniculate cartliages
What forms the false vocal cords?
The horizontal part of the vestibular fold
The vocal ligament and the vocalis m are covered by a mucosa-lined membrane comprising the _____.
vocal fold
Note: It is the vocal fold that vibrates during speech, not the vocal ligament or cord.
When can air pass the rima glottis?
When the vocal folds are abducted
the vocal fold is the upper border of a larger fold that is called ?
the conus elasticus
What points connects the thyroid, cricoid, and arytenoid cartilages to one another?
The conus elasticus
What is the conus elasticus composed of?
Mainly yellow elastic tissue
What are the borders of the conus elasticus?
Sup: the vocal fold
Inferior: upper edge of cricoid
Anterior: thyroid cartilage and median cricothyroid ligament (lat portion) that attaches the cricoid and thyroid cartilages
What lies between the quadrangular membrane and the small thyroepiglottic muscle?
The saccule of the fusiform laryngeal sinus (ventricle of larynx)
Note: it extends superiorly from the anterior end of the sinus
Why can there be so many unique voices?
Because the crico-arytenoid joint has 3 degrees of freedom
By shortening the cords via the ____ muscle, the pitch is lowered.
Vocalis
By tensing the folds via the _____ m, the vibrations are strong and the pitch rises.
cricothyroid
______ is produced by the pharynx, oral region and nasal passages and is modified by the tongue, lips, and palatine musculature.
Resonance
The opening to the larynx is forcefully closed by the contraction of what
adductor muscles ?
the lateral crico-arytenoid, and the transverse and oblique arytenoid muscles.
What pulls the larynx toward the epiglottis?
The ary-epiglottic muscle
What 3 actions occur during swallowing to protect the larynx? (This is a reflex when god enters the laryngeal vestibule)
A- The opening to the larynx is forcefully closed by the contraction of the
adductor muscles - the lateral crico-arytenoid, and the transverse and oblique arytenoid muscles.
B The larynx is pulled toward the epiglottis by the paired ary-epiglottic
muscles.
C. The epiglottis-larrynx partially folds beneath the posterior 1/3 of the
tongue.
What provides sensory and autonomic innervation above the vocal folds.
The internal laryngeal nerve
What accompanies the internal laryngeal nerve?
The super laryngeal artery
What branch of the superior laryngeal nerve provides motor sensation to the cricothyroid muscle?
The external laryngeal nerve
What nerve travels with the superior thyroid artery and is in danger during thyroid surgery?
The external laryngeal nerve
What nerve supplies the muscles of the larynx and sensation below the vocal cords?
The inferior laryngeal nerve ( a branch of the recurrent laryngeal)
What nerve is a terminal branch of the recurrent laryngeal nerve that supplies the muscles of the larynx below the vocal cords?
Inferior laryngeal nerve
What nerve travels with the inferior laryngeal artery and passes behind the thyroid gland where it is at risk in thyroid surgery?
The inferior laryngeal nerve
Where are the lower motor neurons for all the muscles of the larynx, including the stylopharyngeus?
The nucleus ambiguous
What 1st order neurons does the superior (jugular) ganglion contain?
Those that mediate sensation (pain and touch)
Where do 1st order neurons from superior (jugular) ganglion synapse?
Pain: nucleus of the spinal tract
Touch: the pontine nucleus
What 1st order neurons does the inferior (nodose) ganglion contain?
Those for non-conscious information
Where do the 1st order neurons from the inferior (nodose) ganglion project to?
The solitary nucleus in the brainstem.
The nodose ganglion also contains (besides non-conscious) 1st order neurons whose peripheral axons convey ____ from the area of the epiglottis. The central axons of these neurons project to the _____ that is a specialized region of the solitary nucleus.
taste
taste center
What pathology of the vocal folds is characterized by small growths that are caused by overuse. Results in a raspy voice. Might require surgical removal.
Nodules
What pathology of the vocal folds is characterized by benign lesions that can produce a hoarse, breathy voice that tires easily. May require surgery.
Polyps
What pathology of the vocal folds is due to inadequate hydration of the vocal folds. A thick mucous prevents the folds from vibrating correctly.
Laryngitis (sicca)
