Anatomy of Phonation- section 2 Intrinsic Muscles Lecture 10/19/12 Flashcards
Which muscles make fine adjustments?
Intrinsic
What are characteristics of intrinsic muscles?
- they make fine adjustments
- they open, close, tense, and relax vocal folds
- categorized by their effects on shape of glottis and on vibratory behavior of vocal folds
- they always act in pairs
Where is the insertion and origin of the intrinsic muscles?
Laryngeal cartilages
What are intrinsic muscles responsible for?
Control of sound production
What two ways does the intrinsic muscles adjust the larynx?
- medial compression
- longitudinal tension
What is medial compression?
Force with which vocal folds brought together
What is longitudinal tension?
stretching force
What muscles are INSIDE the larynx?
Intrinsic muscles
What are the five major functions of the intrinsic muscles?
- Adduct
- Abduct
- Tense
- Relax
- Auxiliary Musculature (misc)
What are the characteristics of the extrinsic muscles?
- Laryngeal elevators and depressors
- make major adjustments
- elevate order and press the larynx
- one of its attachment is to structures outside the larynx
- responsible for support and fixation of larynx in neck
What does abductor means?
To take away. To separate
Adductors means?
To add. To bring together
What are the adductor muscles?
- lateral crioarytenoid
- oblique arytenoid
- transverse arytenoid
What is the lateral cricoarytenoid?
- helps bring the vocal folds together
- attached to the cricoid and the musculature process of the arytenoid
- causes muscular process to move forward and medially
- adducts vocal folds- rotates vocal process towards midline
- pg 190
What is the transverse arytenoid?
- unpaired muscle spanning the posterior surface of both the arytenoid cartilages.
- runs from the lateral margin of the posterior surface of one arytenoid to the corresponding surface of the other arytenoid
What is the function of the transverse arytenoid?
- to pull the two arytenoids closer.
- To approximate the vocal folds
- Provides support for closing of the vocal folds
- an important element of medial compression
What is the oblique arytenoid muscle?
Paired muscle
- superficial to the transverse arytenoid muscle
- X shaped
- Promotes adduction, enforces medial compression, and rocks the arytenoids (vocal folds) down and in
- Aids in pulling the epiglottis to cover the larynx.
do we use less muscles during abduction or adduction?
abduction because we use the vocal folds for phonation, the force of air forces the vocal folds apart and it doesn’t need any more help to pull them apart.
What is the only abductor muscle?
posterior cricoarytenoid
Where does the posterior cricoarytenoid originate?
Posterior cricoid lamina
True or False:
Fibers project up and out to insert into the posterior aspect of the muscular process of the arytenoid cartilage during abduction
True
Where is the posterior cricoarytenoid antagonistic (work together in opposite directions) to?
lateral cricoarytenoids
What is pars oblique?
Slides thyroid cartilage forward
What is pars recta?
- Reduces distance between cricoid arch and thyroid lamina- vocal folds lengthened and tensed
- contraction of the pars recta rocks the thyroid cartilage downward, which rotates upon the cricothyroid joint.
- rocking the thyroid cartilage forward stretches the vocal folds
- this action increases the distance between the posterior cricoid and thyroid cartilages
What is primary tensor?
Rocks the thyroid cartilage forward relative to the cricoid cartilage
what are the glottal tensors/ tensor muscles?
- Cricothyroid
- Pars rectus (recta)
- Pars oblique
- Thyrovocalis
What is pars oblique?
- Helps slide the thyroid forward
Which muscle is the mass of the vocal folds?
Thyrovocalis
What is Thyrovocalis (vocals)?
- Makes up main mass of vibrating vocal folds
- principle function is regulator of longitudinal tension
Characteristics of the Thyrovocalis?
- contraction draws the thyroid and cricoid cartilages father apart in front
- antagonistic to the cricothyroid muscle (which draws the thyroid and cricoid cartilages together)
- When not opposed by other muscles, relaxes vocal folds and may assist in closing glottis by drawing muscular process forward
- when opposed by other muscles, tense vocal folds
What is the thyromuscularis?
A paired muscle that is a relaxer
What are the auxiliary musculature?
- superior thyroarytenoid muscle
- thyroepiglottic
- aryepiglottic muscle
What are the 3 adductor muscles?
- lateral crioarytenoid
- transverse arytenoid
- oblique arytenoid
What are the intrinsic muscles?
- lateral cricoarytenoid
- transverse arytenoid
- oblique arytenoid
- posterior cricoarytenoid
- cricothyroid
- thyrovocalis
- thromuscularis
- superior thyroarytenoid muscle
- thyroepiglottis
- aryepiglottis
What is the relaxer muscle?
thyromuscularis
What are the auxiliary musculature?
- superior thyroarytenoid muscle
- thyroepiglottis
- aryepiglottis
What muscle is associated with pitch control?
Cricothyroid (w/ two heads)
- pars rectus - pars oblique
What does the thyromuscularis do?
- It is a paired muscle.
- Lateral to each thyrovocalis and with the vocalis make up the thyroarytenoid muscle .
What does the cricoarytenoid do?
adduct and lengthen the folds
