laryngeal muscles

Question 1

Membranous Glottis

Answer 1

3/5th of anterior portion

Question 2

Cartilaginous Glottis

Answer 2

remainder posterior 2/5ths

Question 3

Vestibule

Answer 3

Supraglottal region that begins inferiorly just above the ventricular folds to the opening of the larynx

Question 4

Subglottal Atrium

Answer 4

from vocal folds (just below glottis) and below-lined with cilia to help remove mucus accumulations and foreign matter from respiratory tract

Question 5

Valleculae

Answer 5

space between epiglottis and root of tongue

Question 6

Ventricle (Laryngeal Ventricle)

Answer 6

small supraglottis region between vocal folds and ventricular folds

Question 7

Ventricular Folds

Answer 7

aka False folds-soft and flaccid indentations-incapable of becoming tense-under normal circumstances do not vibrate during phonation-false glottis is larger than actual glottis

Question 8

Intrinsic muscles

Answer 8

muscles that have both attachments inside the larynx

Question 9

Cricothyroid muscles

Answer 9

• bilateral pairs of mms fibers that span superiolaterally between the cricoid and thyroid cartilages
• pars recta (VERTICAL)
• pars oblique (ANGLED)
• pulls thyroid down toward cricoid
• ELONGATES VFs
• major pitch regulator

Question 10

Pars Recta

Answer 10

VERTICAL mms fibers

• rocks thyroid anteriorly and inferiorly (forward and down), closer to cricoid
• inferior border of thyroid

Question 11

Pars Oblique

Answer 11

• ANGLED
• inferior horn of thyroid
• pulls thyroid anteriorly

Question 12

Cricothyroid muscles overall action

Answer 12

• rock cricoid and thyroid closer to the other
• lengthens VFs, thus increasing tension and decreasing mass
• affecting pitchincrease length and tension of VFs

Question 13

Posterior Cricoarytenoid (PCA)

Answer 13

ONLY VF ABDUCTOR

-large fan shaped muscle located on the dorsal surface of the cricoid

Question 14

PCA origin

Answer 14

posterior cricoid lamina

Question 15

PCA insert

Answer 15

muscular process of arytenoid

Question 16

PCA action

Answer 16

abducts the arytenoids, thus abducting the VFs

*only Vf abductor of larynx

Question 17

Lateral Cricoarytenoid (LCA)

Answer 17

small muscle, yet very important for vocalization

Question 18

LCA origin

Answer 18

lateral portion of the cricoid cartilage

Question 19

LCA insert

Answer 19

posterosuperior (back and up) course to the lateral half of the muscular process of the arytenoid cartilage

Question 20

LCA action

Answer 20

ADDUCTION, or bringing the VFs together

• antagonist to PCA
• involved in medial compression-the force exerted to close VFs
• closes membranous glottis

Question 21

Interarytenoids (IA)

Answer 21

between the arytenoids

• includes oblique arytenoid and the transverse arytenoid muscles
• closes cartilaginous glottis

Question 22

OIA action

Answer 22

adduct VFs
agonist (works with) to LCA
-runs across diagonally

Question 23

TIA action

Answer 23

powerful VF adductor, draw apexes together

-runs laterally

Question 24

Thryoarytenoid (TA)

Answer 24

extends anterior-posteriorly (front to back) to make up the muscle mass of the vocal folds (true vocal folds) composed of medial and lateral parts

Question 25

Medial TA (vocalis)

Answer 25

inserts to vocal process

Question 26

Lateral TA (muscularis)

Answer 26

inserts to muscular process

Question 27

TA action

Answer 27

decreases distance between the thyroid and arytenoid cartilages, thus shortening VFs - acts as a regulator of longitudinal tension - PITCH - when unopposed by other mm's, TA relaxes VFs - when opposed by other mm's, increase in tension of VFs

Question 28

Cover of VFs

Answer 28

epithelium and superficial layer of lamina propria

Question 29

Transition of VFs

Answer 29

immediate and deep layers of lamina propriaalso make up vocal ligament

Question 30

Body of VFs

Answer 30

throarytenoid muscles

Question 31

Extrinsic Laryngeal Muscles (strap muscles)

Answer 31

muscles that have 1 attachment to structures outside of the larynx-primarily responsible for the support of the larynx and for fixing it in position

Question 32

Infrahyoids

Answer 32

- point of attachment outside of larynx is below hyoid bone - when mm's contract, they pull the larynx down - origin is inferior to insertion - 4 - sternohyoid, sternothyroid, omohyoid, thryohyoid

Question 33

suprahyoids

Answer 33

- attachment outside larynx is above hyoid bone - when mm's contract, pull larynx and hyoid up - origin is superior to insertion - important for swallowing - digastric, stylohyoid, mylohyoid (mandible), geniohyoid (tongue)

Question 34

skeletal muscles

Answer 34

- under voluntary control - made up of individual mms fibers - uniquely it can contract - moves structure to which it attaches

Question 35

type 1 mms fibers

Answer 35

- aka slow twitch - slow contraction time, 10-30 twitches/sec - sustain mms construction for long time w/o fatigue - marathon runner, smaller, run 4 hours

Question 36

type 2a mms fibers

Answer 36

- fast twitch - higher fire rate, 30-70/sec - fatigue quicker - large amount of force for brief amount of time

Question 37

type 2x mms fibers

Answer 37

- twice as fast contraction as type 2a | - relatively fatigue resistant (not as much as type 1)

Question 38

type 1 and 2 laryngeal mms

Answer 38

- mms involved in glottal closure has a high proportion of type 2 fibers and are FAST contracting (must be fast for like sustenance) - mms involved in respiration (slow process) and pitch change (lasts over several words and phrases) has more type 1 fibers and are SLOWER contracting