Larynx Flashcards
What does the larynx connect?
The lower part of the pharynx to the trachea
Name the functions of the larynx. (3)
1) Prevents the passage of food into the airway during swallowing
2) Regulates the flow of air into the lungs
3) Functions in vocalization
How long is the larynx in an adult?
5 cm long
Where does the larynx lie (what vertebral level)?
Between C3 and C6
Name the 6 cartilages of the larynx.
1) Thyroid
2) Cricoid
3) Epiglottic
4) Arytenoid
5) Corniculate
6) Cuneiform
What are the features of the thyroid cartilage? (7)
1) Superior Thyroid Notch
2) Inferior Thyroid Notch
3) Laryngeal prominence- anterior median elevation
4) Superior horn (attached to the greater horn of the hyoid bone)
5) Inferior horn (articulates with cricoid cartilage)
6) Laminae
7) Oblique line (located on external surface of lamina)
What muscles attach on the oblique line?
Inferior constrictor, sternothyroid, and thyrohyoid muscles
What are the parts of the cricoid cartilage? (2)
1) Narrow anterior arch
2) Broad posterior lamina
Which cartilage is the most inferior of the laryngeal cartilages?
Cricoid cartilage
Which cartilage lies behind the root of the tongue and body of the hyoid bone?
Epiglottic cartilage
How does the lower end of the epiglottic cartilage attach to the back of the laryngeal prominence of the thyroid cartilage?
Thyroepiglottic ligament
Which of the 6 laryngeal cartilages are paired?
Arytenoid, corniculate, and cuneiform
What are the parts of the arytenoid cartilages?
Vocal process and muscular process
What does the vocal process give attachment to?
The vocal ligament
What does the muscular process give attachment to?
Intrinsic muscles of the larynx
Which cartilages lies in the arytenoid cartilages and are closed within the aryepiglottic fold?
Corniculate cartilages
Which cartilages lie in the aryepiglottic folds anterior to the corniculate cartilages?
Cuneiform cartilages
Which cartilages have the ability to ossify and can be mistaken for a fracture on xray?
Corniculate and cuneiform cartilages
What are the two joints of the larynx and which types of joints are they?
Cricothyroid and cricoarytenoid joints
Synovial joints
Where is the cricothyroid joint located?
Between the side of the cricoid cartilage and the inferior horn of the thyroid cartilage
What type of movement does the cricothyroid joint permit?
Rotation of the thyroid cartilage around a horizontal axis
Where is the cricoarytenoid joint located?
Between the upper border of the cricoid cartilage and the base of the arytenoid cartilage
What type of movement does the cricoarytenoid joint permit?
Gliding and rotation of the arytenoid cartilage on the cricoid cartilage
Where does the thyrohyoid membrane extend from?
The thyroid cartilage to the hyoid bone
What is the thyrohyoid membrane pierced by on each side?
Internal laryngeal nerve and the superior laryngeal vessels
Where does the median cricothyroid ligament extend from?
The arch of the cricoid cartilage to the thyroid cartilage
Where does the vocal ligament extend from?
The thyroid cartilage in front to the vocal process of the arytenoid cartilage behind
What is the conus elasticus and where does it extend from?
A fibrocartilage membrane; extends upward from the cricoid cartilage to the vocal ligament
What does the quadrangular membrane connect?
The epiglottic cartilage to the arytenoid cartilage on each side
What does the superior margin of the quadrangular membrane form?
The aryepiglottic ligament within the aryepiglottic fold
What does the inferior margin of the quadrangular membrane form?
The vestibular ligament within the vestibular fold
Which two folds make up the larynx?
1) Vestibular Folds (False vocal cords)
2) Vocal Folds (True vocal cords)
Which two structures does the vocal folds contain?
Vocal ligament and vocalis muscle
What is the rima vestibuli?
The space between vestibular folds
What is the rima glottidis?
The space between the vocal folds. It is the narrowest part of the laryngeal cavity
What does the glottis include?
Rims glottidis and vocal folds
How many cavities is the larynx divided into by the vestibular and vocal folds?
1) Laryngeal Vestibule (extends from laryngeal inlet to the vestibular folds)
2) Laryngeal Ventricles (lie between the vestibular folds and vocal folds)
3) Infraglottic Cavity (extends from the vocal folds to the inferior border of the cricoid cartilage)
What is the small diverticulum within the laryngeal ventricle?
Laryngeal saccule
What is the function of the laryngeal saccule?
Contains glands that lubricate the vocal folds (oil can of vocal folds)
What is the clinical significance of the laryngeal saccule?
1) In hoarseness (partial aphonia) due to excessive singing or speaking, lubricant from laryngeal saccule is temporarily depleted
2) Laryngitis: inflammation of vocal fold
Name the extrinsic muscles that elevate the larynx as a whole. (6)
1) Thyrohyoid
2) Stylohyoid
3) Mylohyoid
4) Digastric
5) Stylopharyngeus
6) Palatopharyngeus
Name the extrinsic muscles that depress the larynx as a whole. (3)
1) Omohyoid
2) Sternohyoid
3) Sternothyroid
Origin of the cricothyroid muscle.
Cricoid cartilage
Insertion of the cricothyroid muscle.
Inferior horn and lower lamina of thyroid cartilage
Nerve of the cricothyroid muscle.
External laryngeal nerve
Function of the cricothyroid muscle.
Tilts thyroid cartilage downward or cricoid cartilage upward thereby tensing the vocal cords (raises pitch of voice)
Origin of the posterior cricoarytenoid muscle.
Posterior surface of lamina of cricoid cartilage
Insertion of the posterior cricoarytenoid muscle.
Muscular process of arytenoid cartilage
Nerve of the posterior cricoarytenoid muscle.
Recurrent laryngeal nerve
Function of the posterior cricoarytenoid muscle.
Abducts the vocal folds
What are the intrinsic muscles of the larynx involved in?
Speech
Origin of the lateral cricoarytenoid muscle.
Arch of cricoid cartilage
Insertion of the lateral cricoarytenoid muscle.
Muscular process of arytenoid cartilage
Nerve of the lateral cricoarytenoid muscle.
Recurrent laryngeal nerve
Function of the lateral cricoarytenoid muscle.
Adducts the vocal cords
Origin of the transverse arytenoid muscle.
Posterior surface of arytenoid cartilage
Insertion of the transverse arytenoid muscle.
Posterior surface of opposite arytenoid cartilage
Nerve of the transverse arytenoid muscle.
Recurrent laryngeal nerve
Function of the transverse arytenoid muscle.
Adducts the vocal folds (function in coughing)
Origin of the oblique arytenoid muscle.
Muscular process of arytenoid cartilage
Insertion of the oblique arytenoid muscle.
Apex of opposite arytenoid cartilage
Nerve of the oblique arytenoid muscle.
Recurrent laryngeal nerve
Function of the oblique arytenoid muscle.
Adducts the vocal folds (function in coughing)
Origin of the aryepiglottic muscle.
Apex of arytenoid cartilage
Insertion of the aryepiglottic muscle.
Side of epiglottic cartilage
Nerve of the aryepiglottic muscle.
Recurrent laryngeal nerve
Function of the aryepiglottic muscle.
Closes the laryngeal inlet
Origin of the thyroepiglottic muscle.
Inner surface of thyroid lamina
Insertion of the thyroepiglottic muscle.
Lateral margin of epiglottis
Nerve of the thyroepiglottic muscle.
Recurrent laryngeal nerve
Function of the thyroepiglottic muscle.
Opens the laryngeal inlet
Origin of the thyroarytenoid muscle.
Inner surface of thyroid lamina
Insertion of the thyroarytenoid muscle.
Arytenoid cartilage
Nerve of the thyroarytenoid muscle.
Recurrent laryngeal nerve
Function of the thyroarytenoid muscle.
Shortens and relaxes vocal folds by drawing the arytenoid cartilages forward (lowers pitch)
Origin of the vocalis muscle.
Inner surface of thyroid lamina
Insertion of the vocalis muscle.
Vocal process of arytenoid cartilage
Nerve of the vocalis muscle.
Recurrent laryngeal nerve
Function of the vocalis muscle.
Adjusts tension on the vocal cords during phonation (fine tuning of vocal cord)
Why are the vocal folds important in phonation?
They control the stream of air passing through the rima glottidis
What is altered during phonation and respiration by movements of the arytenoid cartilages?
Size and shape of the rima glottidis
During what action is the rima glottidis wide? Narrow and wedge shaped?
Inspiration
Expiration and phonation
What is voice dimorphism determined by?
1) Length of vocal cords
2) Size of resonating chamber
3) Thickness of vocal cords (responds to androgens)
What nerves innervates the larynx? (3)
1) Recurrent Laryngeal Nerve
2) Internal Laryngeal Nerve
3) External Laryngeal Nerve
Which nerve is the most important nerve of the larynx?
Recurrent Laryngeal Nerve
What structures does recurrent laryngeal nerve supply motor and sensory function to?
Motor: All of the intrinsic muscles of the larynx except cricothyroid
Sensory: Mucosa of the larynx below the vocal fold
What is the internal laryngeal nerve a branch of?
The superior laryngeal nerve
What structure receives sensory innervation from the internal laryngeal nerve?
Mucosa of the larynx above the vocal folds
Which nerve runs with the superior laryngeal artery and pierces the thyrohyoid membrane to enter the larynx?
Internal laryngeal nerve
What is the external laryngeal nerve a branch of?
The superior laryngeal nerve
Which muscles does the external laryngeal nerve supply motor innervation to?
Cricothyroid and inferior constrictor muscles
Which two arteries provide blood supply to the larynx?
Superior laryngeal artery from the superior thyroid artery and the inferior laryngeal artery from the inferior thyroid artery
