LARYNX REVIEW: LOCATION HYOID BONE STERNOCLEIDO- MASTOID MUSCLE LARYNGEAL PROMINENCE OF THYROID CARTILAGE = ADAM'S APPLE - LEVEL C4 THRYOID GLAND Larynx Functions - produces sound regulates opening to trachea, respiratory system CLINICAL - OBSTRUCTION OF LARYNX CAN PRODUCE SUFFOCATION TRACHEA

LARYNX: IMAGING CADAVER SECTION CT SECTION LARYNX LARYNX PHARYNX + ESOPHAGUS COMMON CAROTID A., IJV BODIES OF CERVICAL VERTEBRAE CLINICAL: PALPATE CAROTID BIFURCATION LATERAL TO LARYNGEAL PROMINENCE - NERVES TO LARYNX CAN BE DAMAGED DURING CERVICAL DISC REPAIR

LARYNX REVIEW: CARTILAGES ARYTENOID - 2 pyramidal shaped cartilages above lamina of cricoid Sup. Horn Corniculate Cartilages Arytenoid Laryngeal prominence = Adam's apple lamina Cricoid Inf. Horn THYROID CARTILAGE - shield shaped has Sup. and Inf. Horns Laryngeal prominence CRICOID = signet ring - complete ring of cartilage - narrow Arch ant., broad Lamina post.

LARYNX REVIEW: SYNOVIAL JOINTS THYROID and CRICOID ARYTENOID and CRICOID SLIDING SYNOVIAL JOINT BETWEEN ARYTENOID AND CRICOID ROTATION HINGE JOINT TILT JOINTS PERMIT ROTATION AND SLIDING: - OPEN OR CLOSE LARYNX (ABDUCT OR ADDUCT VOCAL LIGAMENTS) JOINTS PERMIT TILTING OF THYROID-CRICOID: - CHANGE PITCH OF SOUND (TENSE OR RELAX VOCAL LIGAMENTS)

SOUND PRODUCTION: CONUS ELASTICUS CONUS ELASTICUS -= INTERNAL ELASTIC MEMBRANE ATTACHED TO CRIOCID; UPPER FREE EDGES = VOCAL LIGAMENTS VOCAL LIGAMENTS EXTEND FROM ARYTENOID TO THYROID, ACROSS TWO JOINTS top view VOCAL LIGAMENTS = FREE EDGE OF CONUS CONUS ELASTICUS RIMA GLOTTIDIS = opening

CHANGE PITCH BY TILTING AT HINGE JOINT – Thyroid cartilage tilts down; cricoid tilts up Tilting - STRETCHES vocal ligaments ARYTENOID THYROID HINGE JOINT HINGE JOINT CRICOID STRETCH vocal ligament INCREASE PITCH - CRICOTHYROID RELAX vocal ligament DECREASE PITCH - THYROARYTENOID

MUSCLES OF LARYNX Tilting - STRETCHES vocal ligaments HINGE JOINT STRETCH vocal ligament INCREASE PITCH - CRICOTHYROID CRICOTHYROID M. - Tenses Vocal Ligament Increasing Pitch

MUSCLES OF LARYNX NOT SEE THYROARYTENOID THYROID HINGE JOINT THYROARYTENOID MUSCLES - adjacent to vocal ligament - Relaxes Vocal Ligaments Decreases pitch CRICOID RELAX vocal ligament DECREASE PITCH - THYROARYTENOID

OPEN CLOSE CLOSE OPEN AND CLOSE RIMA GLOTTIDIS BY ROTATING/SLIDING ARYTENOIDS - Rotate laterally opens; Rotate medially or slide closes OPEN CLOSE CLOSE ROTATE LATERALLY ROTATE MEDIALLY SLIDE POSTERIOR CRICO-ARYTENOID LATERAL CRICO-ARYTENOID ARYTENOIDEUS REST POSITION Larynx open for deep breathing; close for speech; completely close to raise abdominal pressure (Valsalva maneuver)

MUSCLES OF LARYNX ARYTENOIDEUS 5) ARYTENOID (Transverse and oblique arytenoid) - Adduct vocal folds 4) LATERAL CRICO- ARYTENOID - Adduct vocal folds 3) POSTERIOR CRICO-ARYTENOID – Abducts vocal fold Adduct closes rima glottidis Abduct opens rima glottidis POSTERIOR CRICO-ARYTENOID LATERAL CRICO-ARYTENOID

LARYNGOSCOPE VIEW OF LARYNX Post. Corniculate cartilage Vocal Folds (true vocal folds) Pyriform recess Cuneiform cartilage Vestibular Folds (false vocal folds) Epiglottis Tongue Ant. NOSE VIEW FOR INTUBATION

CORONAL SECTION VESTIBULE - inlet above false vocal folds VESTIBULAR (FALSE VOCAL) FOLDS - overlie vestibular ligaments (lower edge of Quadrangular membrane) VOCAL (TRUE VOCAL) FOLDS - overlie vocal ligaments (upper edge of Conus elasticus) Quadrangular membrane VENTRICLE - lateral outpocketing Conus elasticus CLINICAL - MUCOSA SWELLS IN ANAPHYLAXIS; OBSTRUCTION CAN RESULT FROM SWELLING AT VESTIBULAR (FALSE VOCAL FOLDS)

NERVES OF LARYNX – Branches of Vagus 1) Superior Laryngeal N. a) Internal Laryngeal N. Visceral Sensory (GVA) to Larynx Above (true vocal folds) b) External Laryngeal N. Branchial motor (SVE) to Cricothyroid 2) Recurrent Laryngeal n. - Visceral Sensory (GVA) to Larynx Below True Vocal Folds - Branchial motor (SVE) to all other Muscles of Larynx SUP. LARYNG. N. Int. Laryng. N. Ext. Laryng. N. RECURRENT LARYNG. N. Clinical - damage to Recurrent Laryngeal nerve in Thyroid surgery

NERVES OF LARYNX – Branches of Vagus SUPERIOR LARYNGEAL NERVE SUPERIOR LARYNGEAL NERVE - pierces thyrohyoid membrane LEFT RECURRENT LARYNGEAL NERVE - passes under Arch of Aorta RIGHT RECURRENT LARYNGEAL NERVE - passes under Subclavian Artery

OBSTRUCTION OF LARYNX: CRICOTHYROTOMY Cricothyroid Membrane CLINICAL - IN OBSTRUCTION OF LARYNX, EMERGENCY OPENING MADE IN CRICOTHYROID MEMBRANE (CRICOTHYROTOMY); AVOIDS BLLEDING THAT CAN OCCUR IN TRACHEOTOMY (FROM INFERIOR THYROID VEINS)

Good luck!