G55: Larynx Flashcards
Larynx function
produce voice, connect pharynx to trachea, respiratory system, patency of airway
Level of larynx
C3-C6
Cartilages that make up the larynx
thyroid, cricoid, epiglottic,(unpaired) arytenoid, corniculate, cuneiform (paired)
Thyroid cartilage
large, hyaline cartilage, 2 lamina fused, laryngeal prominence, thyroid notch, superior horn attached to hyoid, inferior horn articulates with cricoid
Cricoid cartilage
hyaline cartilage; ONLY complete ring, narrow in front, wide in back, articulate with inferior horns of thyroid cartilage and arytenoid cartilages
Epiglottic cartilage
Elastic, behind root of tongue, attached to thyroid cartilage and hyoid bone
What ligament attaches the epiglottic cartilage and thyroid cartilage?
Thyroepiglottic ligament
What ligament attaches the epiglottic cartilage and hyoid bone?
Hyoepiglottic ligament
Arytenoid cartilage
Hyaline, pyramidal, base articulate with cricoid, apex points posterior and medially, 2 processes - vocal and muscular
Vocal process of arytenoid cartilage
projects into interior of the larynx, pointing toward thyroid cartilage, vocal ligament attaches here
Muscular process of arytenoid cartilage
projects laterally, process is short and blunt attachment site for posterior cricoarytenoid and lateral cricoarytenoid
Corniculate cartilage
elastic, on apex of arytenoid
Cuneiform cartilage
elastic, aryepiglottic folds
Thyrohyoid membrane
runs between hyoid bone and thyroid cartilage; pierced by SUPERIOR LARYNGEAL A and INTERNAL LARYNGEAL N
Quadrangular membrane
from lateral margin of epiglottis to arytenoid cartilage; upper edge - aryepiglottic fold, lower edge under vestibular fold
Median cricothyroid ligament:
elastic tissue connecting cricoid cartilage and thyroid cartilage
Vocal ligament
vocal process of arytenoid cartilage to posterior surface of thyroid cartilage
cricovocal membrane
attached to vocal ligament superiorly and cricoid cartilage inferiorly and laterally
Conus elasticus
median cricothyroid ligament + cricovocal membreane (ILL-DEFINED)
Cricothyroid joint
inferior horn of thyroid and criocoid; rotary and gliding motion
Cricoarytenoid joint
base of arytenoid cartilage and posterior surface of cricoid cartilage; gliding and rotation movements
Extrinsic muscles of larynx
attach on outer surface, move whole larynx
ELEVATORS OF larynx
THYROHYOID, STYLOPHARYNGEUS, PALATOPHARYNGEUS AND SUPRAHYOID via thyrohyoid membrane
DEPRESSORS OF larynx
STERNOTHYROID, OMOHYOID, STERNOHYOID
Cricothyroid attachments
cricoid to inferior horn of thyroid cartilage
Cricothyroid Action
tenses and elongates vocal ligament (tilts thyroid anterior)
Cricothyroid innervation
external branch of Superior laryngeal n
Posterior cricoarytenoid attachment
posterior cricoid to MUSCULAR process of arytenoid
Posterior cricoarytenoid action
opens rima glottidis (abducts vocal folds)
Posterior cricoarytenoid innervation
recurrent (inferior) laryngeal n.
Lateral cricoarytenoid attachment
lateral side of cricoid to muscular process of arytenoid
Lateral cricoarytenoid action
closes rima glottidis (adducts vocal folds)
Lateral cricoarytenoid innervation
recurrent (inferior) laryngeal n.
Arytenoid attachment
posterior sufaces of adjacent arytenoid cartilage
Arytenoid action
closes rima glottidis (arytenoid approximate)
Arytenoid innervation
recurrent (inferior) laryngeal n.
Thyroarytenoid attachment
inner surface of thyroid cartilage inserts on base of arytenoid cartilage (medial portion inserts on vocal process
Thyroarytenoid action
decreases tension on vocal ligament by drawing thyroid and arytenoid closer together
Two muscles of the thyroarytenoid m
vocalis: thyroid to vocal process of arytenoid
thyroepiglottic m: prolonged fibers of thyroarytenoid along the aryepiglottic fold
Action of Vocalis
produce high tones, increase tension in part
Laryngeal aditus
superior opening into larynx from pharynx
Vestibule
immediate opening between epiglottis and aryepiglottic folds
Vestibular folds
upper fold; thick ridge of mucosa
Vocal folds
lower fold; enclose vocal ligaments and part of arytenoid cartilage
Ventricle
lies between to vestibular and vocal folds
Rima Vestibuli
opening between the vestibular folds
Rima glottidis
opening between the vocal folds
Glottis
Rima glottidis + vocal folds (and parts of the arytenoid cartilage)
Infraglottic cavity
space below vocal folds; continuous inferiorly with trachea
Innervation to larynx
Branches of Vagus - internal laryngeal and recurrent laryngeal
Internal laryngeal n
branch of superior laryngeal n. supplies sensory above the vocal folds; pierces the thyrohyoid membrane
Motor innervation to the cricothyroid m
external branch of superior laryngeal m
When does the recurrent laryngeal become the inferior laryngeal?
level of superior to cricothyroid joint
All other intrinsic muscles of the larynx are innervated by…
recurrent laryngeal n
What structures need you be worried about in a tonsillectomy?
facial a/v and glossopharyngeal
What structures may be damaged by thyroid surgery?
recurrent laryngeal n.
unilateral section of recurrent laryngeal will cause
hoarseness
bilateral section of recurrent laryngeal will cause
suffocation, cricothyroid closes rima glottidis and its innervated by internal laryngeal (unopposed action)
Blood supply to larynx
Superior laryngeal a from the superior thyroid a (external carotid) courses with internal laryngeal n.
Inferior laryngeal a from inferior thyroid a (thyrocervical trunk) courses with recurrent laryngeal (anastomosis)