Text ch. 4 Anatomy of Phonation (Larynx) Flashcards
This laryngeal cartilage looks like a signet ring with the signet towards the back, sitting on the trachea.
Cricoid cartilage
The cricoid and thyroid cartilages articulate at the _____ ____.
cricothyroid
The thyroid cartilage articulates with the cricoid at the cricothyroid joint by means of paired processes that let it rock back and forth. What are the processes called?
Inferior horns of thyroid cartilage.
These paired cartilages ride on the high-backed upper surface of the signet ring shaped cricoid cartilage.
arytenoid cartilages
These cartilages are prominent landmarks in the aryepiglottic folds.
Corniculate cartilages.
These cartilages rest within the aryepiglottic folds and give them a degree of rigidity.
Cuneiform cartilages.
The thyroid cartilages articulates with the hyoid bone by means of paired processes called….?
Superior horn of thyroid cartilage
The cricothyroid joint allows the thyroid and cricoid cartilages to come closer together in the ____.
front
The arytenoid and cricoid cartilages also articulate with a joint that permits a wide range of arytenoid motion. True or false?
True
What are the bands of mucous membrane, connective tissue and thyrovocalis muscle that are slung between the arytenoid cartilages and thyroid cartilages?
Vocal folds
The extrinsic ligaments of the larynx provide attachment between the hyoid or trachea and what?
The cartilage of the larynx.
What stretches across the space between the greater cornu of the hyoid and the lateral thyroid cartilage?
Thyrohyoid membrane
This ligament is posterior to the thyrohyoid membrane and runs from the superior horn of the thyroid to the posterior tip of the greater cornu of the hyoid.
Lateral thyrohyoid ligament
If present, where are the triticial cartilages found?
Lateral thyrohyoid ligament
This ligament runs from the corpus hyoid to the upper border of the anterior thyroid.
Median thyrohyoid ligament
Which membranes and ligaments connect the thyroid cartilage with the hyoid bone and cover the space between them?
- Median thyrohyoid ligament
- Thyrohyoid membrane
- lateral thyrohyoid ligament
What attaches the trachea to the larynx?
cricotracheal ligament
What structure lies between the pharynx and trachea?
Larynx
At about what level is the larynx situation?
3rd to 6th cervical vertebrae
List 6 major functions of the larynx:
- Houses vocal folds and is principal structure for sound production
- Forms part of the respiratory system
- guards air passages while swallowing
- prevents foreign objects from enterint the lungs
- involved in throat clearing and coughing
- connects pharynx with trachea
List 6 major functions of the larynx:
- Houses vocal folds and is principal structure for sound production
- Forms part of the respiratory system
- guards air passages while swallowing
- prevents foreign objects from entering the lungs
- involved in throat clearing and coughing
- connects pharynx with trachea
The larynx is attached to external structures (hyoid bone and trachea) by what?
Extrinsic ligaments and membranes
The cartilages of the larynx are held together by what?
intrinsic ligaments and membranes
Name the extrinsic ligaments/membranes:
- Thryohyoid ligament (broad sheet)
- Lateral thyrohyoid ligament (thin, superior horn of thyroid to hyoid bone)
- Cricotracheal ligament
Name the intrinsic ligaments and membranes:
- Quadrangular membrane (connects epiglottis, thyroid cartilage and arytenoid/corniculate cartilages)
- Aryepiglottic fold (thickening of upper border of quadrangular membrane)
- Medial cricothyroid ligament (small, at midline b/n thyroid and crycoid cartilages)
- Lateral cricothyroid ligament (broader, lateral aspect b/n thyroid and crycoid cartilages)
Vocal ligaments (inner surfaces of arytenoid to midline of thyroid cartilage)
Which 3 ligaments make up the Conus Elasticus?
- Medial and lateral cricothyroid ligaments
* Vocal ligaments
Name the intrinsic ligaments and membranes:
- Quadrangular membrane (connects epiglottis, thyroid cartilage and arytenoid/corniculate cartilages)
- Aryepiglottic fold (thickening of upper border of quadrangular membrane)
- Medial cricothyroid ligament (small, at midline b/n thyroid and crycoid cartilages)
- Lateral cricothyroid ligament (broader, lateral aspect b/n thyroid/Vocal ligaments and crycoid cartilages)
Vocal ligaments (inner surfaces of arytenoid to midline of thyroid cartilage)
The Fibroelastic membrane of the larynx is composed of the upper _____ _______ and _______ _______ and the lower ______ _____ and the vocal ligament.
- quadrangular membranes
- aryepiglottic folds
- conus elasticus
The undergirding layer of connective tissue running from the arytenoids to the epiglottis and thyroid cartilage and forming the false vocal folds.
Quadrangular membrane.
Which muscles courses from the side of the epiglottis to the arytenoid apex and form the upper margin of the quadrangular membrane?
Aryepiglottic muscle
Which muscles courses from the side of the epiglottis to the arytenoid apex and form the upper margin of the quadrangular membrane, and laterally, the aryepiglottic folds?
Aryepiglottic muscle
What is the piriform sinus?
The space between the aryepiglottic fold and the thyroid cartilage.
Which two ligaments attach the epiglottis to the corpus hyoid and inner thyroid cartilage respectively?
- Hyoepiglottic ligament
2. Thyroepiglottic ligament
2 ligaments attaching the epiglottis to the tongue:
- Lateral glossoepiglottic ligament
2. Median glossoepiglottic ligament
The extrinsic laryngeal muscles include which 2 groups?
- Suprahyoid
* Infrahyoid
What is the space between the aryepiglottic fold and the thyroid cartilage called?
The pyriform sinus
The fibroelastic membrane of th larynx is composed of what?
Upper: quadrangular membrane and aryepiglottic folds
Lower: conus elasticus and vocal ligament
What courses down from the side of the epiglottis to to the arytenoid apex?
Aryepiglottic folds
The entry to the vestibule of the larynx from the pharynx above?
Aditus (aditus laryngis)
If thinking of the aditus as a ‘door’ to the larynx, what is the anterior boundary of the ‘frame’ and what are the lateral margins?
- Epiglottis
* aryepiglottic folds
What is the space between the aditus and the ventricular (vestibular, false vocal..) folds called?
Vestibule
What comprises the lateral walls of the vestibule?
the aryepiglottic folds
This begins at the margins of the true vocal folds and extends to the inferior border of the cricoid cartilage.
The conus elasticus
What kind of join is the cricothyroid joint?
Diarthrodial, pivoting joint - permits rotation of the two articulating structures (cricoid and thryroid cartilages)
Anterior midline of the thyroid cartilage where the laminae join.
Thyroid angle
Located at the superior-most point of the thyroid angle:
thyroid notch
Where on the thyroid do the vocal folds attach?
Just behind the notch of the thyroid (below, just, so they are attaching to cartilage).
Which cartilages provide the mechanical structure that permits onset and offset of voicing?
The paired arytenoid cartilages
What are the 2 processes of the arytenoid cartilages?
- Vocal process (project anteriorly towards the thyroid notch. These processes attach to the posterior portion of the vocal folds)
- Muscular process (lateral. Pt of attachment for muscles that adduct and abduct the vocal folds)
The sides of the epiglottis are joined with the arytenoid cartilages via the…?
Aryepiglottic folds.
Which 6 muscles attach to the corpus of the hyoid?
- Mylohyoid
- Sternohyoid
- Omohyoid
- Stylohyoid
- Genioglossus
- Geniohyoid
Name the only functionally mobile points of the larynx:
- Cricothyroid joint
2. Cricoarytenoid joint
What movement is permitted at the cricothyroid joint?
Rotation: thyroid cartilage can rock down in front
2. glide: the thyroid can glide forward and backward slightly, relative to the cricoid.
Which joint of the larynx provides the major adjustment for change in vocal pitch?
The Cricothyroid joint.
Which movements are permitted at the cricoarytenoid joints?
Rocking (inward), gliding (limited anterior-posterior gliding), rotation (a little, maybe)
The base of the arytenoid cartilage is ____ and the mating surface of the cricoid cartilage is _____.
- Concave
2. convex
Which joint provides the mechanism for vocal fold approximation and abduction?
the cricoarytenoid joint
What are intrinsic laryngeal muscles?
Muscles with both origin and insertion on laryngeal cartilages. Intrinsic muscles make fine adjustments of the vocal mechanism.
What are extrinsic laryngeal muscles?
Muscles with one attachement on a laryngeal cartilage and the other on a nonlaryngeal structure. Extrinsic muscles make major adjustments to the larynx, such as elevating or depressing it.
The suprahyoid muscles are extrinsic laryngeal muscles. How many are there? Name them:
4 * Digastric * Mylohyoid * Geniohyoid (make floor of mouth, superficial to deep) * Stylohyoid
The narrow muscle attaching to the inner surface of the mandible and they hyoid bone.
Geniohyoid
The fan shaped muscle spanning the floor of the mouth and attaching to the mandible and hyoid bone.
Mylohyoid
Muscle attaching to the styloid process and hyoid bone.
Stylohyoid
Anterior belly attaching to the hyoid bone and mandible. Posterior belly attaches to hyoid bone and mastoid process. The bellies join via a small tendon that passes through a fibrous look connected to the hyoid bone.
Digastric muscle
As a group, what do the suprahyoid muscles do?
Act as elevators of the hyoid bone and larynx.
Muscle attached to vocal process of arytenoid?
Thyrovocalis
Muscle attached to muscular process of arytenoid?
Thyromuscularis
How many laryngeal adductors are there? How many abductors?
3 Adductors
1 Abductor only
Name the intrinsic muscles of the larynx that fit under the heading “Adductors”
- Lateral cricoarytenoid
- Transverse arytenoid
- Oblique arytenoid
Name the intrinsic muscles of the larynx that fit under the heading “Abuctors”
- Posterior cricoarytenoid
the only one!
Name the intrinsic muscles of the larynx that fit under the heading “Tensors”.
- Thyrovocalis (medial thyroarytenoid)
* Cricothyroid (pars recta, pars oblique)
Name the intrinsic muscles of the larynx that fit under the heading “relaxers”
- Thyromuscularis (lateral thyroarytenoid)
Name the intrinsic muscles of the larynx that fit under the heading “Auxiaiary Musculature”
- Thyroepiglotticus (included because relevant to swallowing)
- Superior thyroarytenoid
- Thyroarytenoid
- Aryepiglotticus
What are the 2 classifications of extrinsic muscles of the larynx?
- Suprahyoid (stylohyoid, mylohyoid, geniohyoid, genioglossus, hyoglossus, inferior phaaryngeal constrictor, digastric muscle)
- Infrahyoid Muscles (Sternothyroid, sternohyoid, omohyoid, thyrohyoid)
Where are the origin and insertion points for the lateral cricoarytenoid muscle, what is its effect and innervation and what kind of (classification) muscle is it?
Origin: Superior-lateral surface of the cricoid (on the low down slow nearer the front) cartilage.
Course: Up and back
Insertion: Muscular process of the arytenoid cartilage.
Effect of contraction: muscular process drawn forward, rocking the arytenoid cartilage inward and downward, adducting the vocal folds (and perhaps lengthening them).
Classification: intrinsic, adductor
Innervation: CN X Vagus nerve
This muscle pulls the muscular process of the arytenoid forward, moving the vocal processes (therefore vocal folds) in towards each other. Movement is rocking the arytenoid inward and downward.
Massively important adductor. The only Abductor works in direction opposition to this muscle.
Lateral Cricoarytenoid
Posterior arytenoid is the direct antagonist
This unpaired muscle is a band of fibres spanning the posterior surface of both of the arytenoid cartilages (ie from posterior view, covering the entire back of the arytenoid cartilages).
Transverse Arytenoid Muscle (transverse interarytenoid muscle)
What is the function of the transverse arytenoid muscle and where does it orginate and insert?
Runs from the lateral margin of the posterior surface of one arytenoid cartilage to the same place on the other arytenoid cartilage. Function: to pull the two arytenoids closer together and to approximate the vocal folds. Provides addditional support for tight occlusion of vocal folds and is an important element of Medial Compression.
What is Medial Compression?
The degree of force that may be applied by the vocal folds at their point of contact. Increased medial compression is a function of increased force of adduction. CN X Vagus inervates the Transverse Arytenoid muscle which is vital in medial compression.
These paired muscles are immediately superficial to the unpaired transverse arytenoid muscle and perform a similar function.
Oblique Arytenoid Muscles (also: Oblique interarytenoid muscles)
These muscles originate at the posterior base of the muscular process of the arytenoid cartilage and course up and across to the opposite arytenoid, inserting at the apex. They cross over each other behind the arytenoid cartilages. They are innervated by CN X Vagus.
Oblique arytenoid Muscle.
These paired muscles work to pull the apex of the arytenoid cartilages medially, promoting adduction of the vocal folds, enforcing medial compression and rocking the arytenoid (and vocal folds) down and in. They also work in concert with the aryepiglottic muscle to pull the epiglottis to cover the aditus.
Oblique arytenoid muscles.
The sole abductor of the vocal folds is called the…?
Posterior Cricoarytenoid Muscle.
This muscle is the direct antagonist to the Lateral cricoarytenoid muscles.
Posterior Cricoarytenoid Muscles.
This muscle originates on the posterior cricoid lamina and projects up and out to insert into the posterior aspect of the muscular process. Contraction pulls the muscular process posteriorly, rocking the arytenoid cartilage out laterally and abducting the vocal folds.
Posterior Cricoarytenoid Muscle
The primary tensor of the vocal folds:
Cricothyroid muscle.
This muscle rocks the thyroid cartilage forward, relative to the cricoid cartilage, moving the attachment points of the vocal folds (onl the arytenoids and thyroid cartilage) away from each other.
Cricothyroid muscle
Origin and insertion points for Cricothyroid Muscle (2 headed)
Pars recta: Origininating on anterior surface of cricoid cartilage beneath arch, courses up and out.
Insertion: lower surface of thyroid lamina
Pars Oblique: Origininates on Cricoid cartilage anterior part, lateral to the pars recta, courses obliquely up. Insertion: juncture between thyroid laminae and inferior horns.
Pars recta and Pars oblique of Cricothyroid Muscle - different movements?
Pars recta: rocks anterior thyroid cartilage down towards cricoid cartilage. Cricoid also raises slightly to at the front. This moves point of attachment of vocal folds on inner thyroid away from attachment on vocal process of arytenoids, stretching the vocal cords.
Pars Oblique: Slide thyroid forward relative to cricoid, also stretching vocal folds.
What is the medial muscle of the vocal folds?
Thyrovocalis muscle.
This muscle originates from the inner surface of the thyroid cartilage near the thyroid notch and courses back to insert into the lateral surface of the vocal process of the arytenoid cartilage.
Thyrovocalis muscle (medial part of thyroarytenoid muscle)
What does contraction of the Thyrovocalis muscle do?
draws the thryoid and cricoid cartilages apart at the front, which makes the thyrovocalis an antagonist of the Cricothyroid muscle. Contraction of thyrovocalis balanced against the cricothyroid muscle contraction, tenses the vocal folds.
These 2 intrinstic laryngeal muscles are both classified as vocal fold tensors, even though they are antagonistic in their movement of the thyroid cartilage relative to the cricoid cartilage:
- Cricothyroid
* Thyrovocalis
Running immediately lateral to the thyrovocalis muscles, these paired muscles are considered vocal fold relaxers.
Thyromuscularis (lateral thyroarytenoid muscle)
This muscle originates on the inner surface of the thyroid cartilage, near the notch (lateral to origin of thyrovocalis). It runs back to insert into the arytenoid cartilage at the muscular process and base.
Thyromuscularis.
What does the thyroarytenoid muscle consist of?
*Thyrovocalis
*Thyromuscularis
paired muscles
Which nerve supplies both sensory and motor for all muscles of the larynx?
CN X Vagus nerve
This muscle is contintinuous with the thyroepiglotticus superiorly, but is not always present. It is assumed to relax the vocal folds.
Superior thyroarytenoid
This muscle arises from the superior aspect of the oblique arytenoid muscle and continues as the muscular component of the aryepiglottic fold as it courses to insert into the lateral epiglottis. This muscle helps protect the airway during swallowing by deflecting the epiglottis over the aditus.
Aryepiglottic muscle
This muscle runs from the inner surface of the thyroid at the angle and course back and up to insert in the lateral epiglottis. It dialates the airway.
Thyroepiglottic muscle.
