head & neck VII: larynx

3 primary fxns of the larynx

1. as a sphincter at the air inlet passage

2. maintain patency of the airway

3. voice production

the larynx is located posteriorly to the bodies of vertebrae __

C3 to C6

the larynx is located laterally to the

carotid sheaths

4 laryngeal cartilages

1. thyroid

2. cricoid

3. arytenoid

4. epiglottic

adam’s apple def

the laryngeal prominence where the two laminae of the thyroid cartilage meet

the thyroid cartilage is open ___ (direction)

posteriorly

the lateral surface of the cricoid cartilage has a facet for articulation with the

inferior horn of the thyroid cartilage

the superior and inferior horns of the thyroid cartilage attach to the

hyoid bone (superior) and cricoid cartilage (inferior)

the upper surface of the cricoid lamina articulates with the base of the

arytenoid cartilage

the only laryngeal cartilage that completely encircles the airway

cricoid cartilage

arytenoid cartilage 2 processes

vocal process

muscular process

the front of the epiglottic cartilage is attached to the

hyoid bone

the stalk of the epiglottic cartilage is attached to the

thyroid cartilage

the sides of the epiglottic cartilage is attached to the

arytenoid cartilages (via aryepiglottic folds)

thyrohyoid membrane fxn

suspends larynx from hyoid bone

the thyrohyoid membrane is pierced by the (3)

superior laryngeal artery

superior laryngeal vein

internal laryngeal nerve

quadrangular membrane location

bw the lateral portions of the arytenoid and epiglottic cartilages

quadrangular membrane free inferior border forms the

paired vestibular ligaments that form the false vocal folds

quadrangular membrane superior edges form the

aryepiglottic folds

anterior portion of conus elasticus connects the

cricoid and thyroid cartilages

free superior border of conus elasticus forms the

vocal ligament

identify 1

epiglottic cartilage

identify 3

arytenoid cartilage

identify 4

hyoid bone

identify 5

thyrohyoid cartilage

identify 6

thyroid cartilage

identify 7

cricoid cartilage

identify 8

trachea

boundaries of laryngeal inlet

in front: epiglottis

laterally: aryepiglottic folds

posterior: mucosa between arytenoids

vestibule of the laryngeal cavity boundaries

inlet to vestibular folds

ventricle of the laryngeal cavity boundaries

bw vestibular and vocal folds

infraglottic cavity of the laryngeal cavity boundaries

bw vocal ligament to lower border of cricoid cartilage

3 sections of the laryngeal cavity

vestibule, ventricle, infraepiglottic cavity

rima glottidis def

opening bw the vocal folds

glottis def

rima glottidis plus the vocal folds

vestibular folds fxn

protect the glottis and infraglottic cavity

the __ contains mucus-secreting glands that lubricate the vocal folds

ventricle

elevator muscles of the larynx

suprahyoid muscles

stylopharyngeus

salpingopharyngues

palatopharyngeus

depressor muscles of the larynx

strap (infrahyoid) muscles

laryngeal sphincter muscles

oblique arytenoid, transverse arytenoid

oblique arytenoid origin + insert

origin: muscular process of arytenoid

insert: apex of opposite arynteoid, then into aryepiglottic folds

oblique arytenoid fxn

adducts arytenoids; adduct aryepiglottic folds

transverse arytenoid origin + insert

origin: back + medial surface of arytenoid

insert: back + medial surface of opposite arytenoid

transverse arytenoid fxn

adducts arytenoid cartilages to close posterior part of rima glottidis

lateral cricoarytenoid origin + insert

origin: lateral part of cricoid arch

insert: back to muscular process of arytenoids

lateral cricoarytenoid fxn

adducts vocal fold

posterior cricoarytenoid origin + insert

origin: back of cricoid lamina

insert: laterally, to muscular process of arytenoid

posterior cricoarytenoid fxn

abducts vocal fold and arytenoid cartilage

identify 1

arytenoid cartilage

identify 2

posterior cricoarytenoid

identify 3

epiglottis

identify 4

thyroid cartilage

identify 5

oblique arytenoid

identify 6

transverse arytenoid

identify 7

cricoid cartilage

identify 8

arytenoid cartilage

identify 9

thyroarytenoid

identify 10

lateral cricoarytenoid

cricothyroid origin + insert

origin: side of cricoid arch

insert: back to lamina, inferior horn of thyroid cartilage

cricothyroid fxn

pulls thyroid cartilage forward, tilts cricoid lamina posteriorly

stretches vocal ligament to raise pitch of voice

thyroarytenoid origin + insert

origin: inner surface of thyroid cartilage near angle

insert: anterior surface + vocal process of arytenoid

thyroarytenoid fxn

stiffens vocal ligament via isometric contrdaction

creates more resistance → produce loud sounds even when vocal folds are abducted

vocalis muscle location + fxn

fibers of thyroarytenoid parallel to the vocal ligament

makes minute adjustments in tension during speech

motor innerv of larynx

recurrent (inferior) laryngeal nerve except cricothyroid (external laryngeal)

sensory innerv of larynx

mucosa upward of vocal folds = internal laryngeal

mucosa below vocal folds = recurrent laryngeal

blood supply of larynx

superior laryngeal artery (from superior thyroid artery)

inferior laryngeal artery (from inferior thyroid artery)

4 functions of larynx

1. swallowing

2. coughing, sneezing

3. micturition, defectation, parturition

4. voice production