Larynx Flashcards
3 Regions of Larynx
Vestibule, Ventricle, Infraglottic
Epiglottic Cartilage
- Single cartilage posterior to tongue & hyoid bone
- Attaches to posterior angle of thyroid cartilage
- Directs food posteriorly toward the esophagus
- Protects opening of larynx
- Elastic cartilage
Thyroid Cartilage
• 2 lamina unite anteriorly, Single cart.
• Stem of epiglottic cartilage attaches
posteriorly
• Anterior ends of vocal ligaments converge below epiglottis
• Inferior thyroid cartilage horns articulate with cricoid cartilage
• Lies between C4 & C6
• Hyaline cartilage
Cricoid Cartilage
- Single cartilage shaped like a signet ring (sm. ant. arch & large post. lamina)
- ONLY complete ring of cartilage of larynx
- Firmly attached to trachea inferiorly
- Lies at C6
- Hyaline cartilage
Arytenoid Cartilage
- Paired small moveable pyramidal shaped cartilages
- Lower surface articulates with cricoid cartilage
- Composed of both vocal & muscular processes
- Vocal processes attach to vocal ligaments anteriorly
- Hyaline cartilage
Corniculate Cartilage
• Paired, minor cartilage • Small horn-shaped cartilages • Rest on apices of arytenoid cartilages • Lie in aryepiglottic fold • Elastic cartilage
Cuneiform Cartilage
• Paired, minor cartilage • Small nodular cartilages • Rest on corniculate cartilages • Lie in aryepiglottic fold • Elastic cartilage
Cricothyroid joints
• Synovial joints between cricoid & thyroid cartilages
• Held together by cricothyroid ligaments
• Anterior & Posterior tilting of thyroid cartilage
• Inferior laryngeal nn. run just posterior to joints
— Increases tension (lengthening) of vocal cords
Larynx: Folds & Cords
• Elevations of mucous membrane = folds
• Vestibular folds – cover vestibular ligaments (false vocal cords)
– Found just superior to vocal folds
• Vocal folds – cover vocal ligaments (true
vocal cords)
– Extend from thyroid angle to arytenoid cartilages
Larynx: Internal Spaces
• Aditus – superior opening (inlet)
• Vestibule – area superior to vestibular
folds (false vocal cords)
• Ventricle – area between vestibular folds & vocal folds
• Infraglottic cavity – area inferior to vocal folds (true vocal cords)
Clinical Notes: Aspiration of Foreign Bodies
• Food, etc. may enter aditus & lodge in vestibule
• Blockage may seal off larynx & produce muscle spasms
• Vocal cords then close – no air passes
• Death results in ~5 min. if larynx not
opened
• May require Heimlich maneuver or cricothyrotomy
Musculature of Larynx
- Cricothyroid = tension. High pitches
- Posterior Crico-arytenoid = open glottis, only one that opens
- Transverse Arytenoid = internal of ^, attach to arytenoid cartilages, adduct vocal ligaments
- Oblique Arytenoid = border is top of transverse aryenoid, close by adduction
- Lateral Crico-arytenoid = deep to cricothyroid, adduct, originate in superior border of cricoid cartilage, insert to muscular process of arytenoid cartilage
- Thyroarytenoid = shortening of ligaments by removing tension (UNIQUE)
Clinical Notes: Laryngospasm
• Posterior cryoarytenoid mm. vital in maintaining open airway
• Laryngospasm is spasmodic closure of glottis
• Life-threatening as breathing becomes impossible
• Spasm of laryngeal mm. may occur from number of causes
– Irritating chemicals, pharmaceutical side effects,
etc.
Larynx: Arterial Supply
• Superior Laryngeal a. – supplies upper larynx
– Br. of Superior Thyroid a. (runs with Internal Laryngeal n.)
• Inferior Laryngeal a. – supplies lower larynx – Br. of Inferior Thyroid a. (runs with Inferior
Laryngeal n.)
• Accompanying veins provide venous drainage
Larynx: Innervation (CN X)
- Superior Laryngeal n. – gives rise to internal & external nn.
- Internal Laryngeal n. – pierces thyrohyoid membrane
- External Laryngeal n. – runs superficial to cricothyroid m.
- Recurrent Laryngeal n. – circles aorta or subclavian a.
- Inferior Laryngeal n. – runs posterior to cricothyroid joint
