The Larynx The Larynx

R. Shane Tubbs, MS, PA-C, PhDR. Shane Tubbs, MS, PA-C, PhD

9 Cartilages9 Cartilages

3 unpaired: epiglottis, thyroid, cricoid3 unpaired: epiglottis, thyroid, cricoid3 paired: arytenoid, corniculate, 3 paired: arytenoid, corniculate,

cuneiformcuneiform

CartilagesCartilagesThyroid: (shield), C4-C5 hyaline, 90Thyroid: (shield), C4-C5 hyaline, 90oo male; male;

120120oo female (subpubic) female (subpubic)Cricoid: C6, hyaline, only complete ring Cricoid: C6, hyaline, only complete ring

therefore can compress the esophagustherefore can compress the esophagusTriticealTriticealEpiglottis: extends to C3, elastic Epiglottis: extends to C3, elastic Cuneiform: elastic, does not contact other Cuneiform: elastic, does not contact other

cartilagescartilagesCorniculate: limited function in man, elastic Corniculate: limited function in man, elastic Arytenoid: ½ elastic ½ hyalineArytenoid: ½ elastic ½ hyalineBy ~age 65 thyroid, cricoid and ½ By ~age 65 thyroid, cricoid and ½

arytenoid are ossifiedarytenoid are ossified

Quadrangular Quadrangular membrane: membrane: submucosal sheet of submucosal sheet of connective tissueconnective tissue

Its free inferior margin Its free inferior margin = vestibular fold= vestibular fold

Its free superior Its free superior margin = aryepiglottic margin = aryepiglottic foldfold

Conus elasticus: Conus elasticus:

(cricothyroid (cricothyroid membrane and membrane and vocal ligament)vocal ligament)

Three Three regions: regions: vestibule vestibule (superior to (superior to false folds), false folds), ventricle ventricle (between (between false above false above true), true), infraglottic infraglottic (folds to (folds to cricoid)cricoid)

Rima (slit) Rima (slit) glottidis glottidis between true between true foldsfolds

Saccule Saccule (appendix)(appendix)

Larynx InnervationLarynx Innervation

MusclesMuscles

Extrinsic: suprahyoid and infrahyoidExtrinsic: suprahyoid and infrahyoid Intrinsic:Intrinsic:

Most Most ImportantImportant Muscle in the Muscle in the Body?Body?

The EarThe Ear

Auricle (Pinna)Auricle (Pinna)

EAM InnervationEAM Innervation

Anterior: auriculotemporal nerveAnterior: auriculotemporal nerve

Posterior: CN X with some CN IX/CN Posterior: CN X with some CN IX/CN VIIVII

Reflexes: bradycardic, cough, emesisReflexes: bradycardic, cough, emesis

Dentally referred otalgia Dentally referred otalgia

EAMEAMLength: adults 2-3 cm, children ~1 cmLength: adults 2-3 cm, children ~1 cm

Medial 2/3 bony; lateral part elastic Medial 2/3 bony; lateral part elastic cartilagecartilage

Lined with skin, Meibomian glandsLined with skin, Meibomian glands

Superficial parotid lymph node just Superficial parotid lymph node just anterior to opening of EAManterior to opening of EAM

External: auriculotemporal, X, ?VII, ?External: auriculotemporal, X, ?VII, ?IXIX

Internal: tympanic plexus, VII (chorda Internal: tympanic plexus, VII (chorda tympani)tympani)

Middle Ear FeaturesMiddle Ear Features

Ossicles (covered with mucous Ossicles (covered with mucous membrane not periosteum)membrane not periosteum)

Stapedius and tensor tympaniStapedius and tensor tympani

Chorda tympaniChorda tympani

Tympanic plexusTympanic plexus

Middle EarMiddle Ear

Roof: Roof: tegmen tegmen tympanitympani

Lateral: Lateral: tympanic tympanic membranemembrane

Medial: Medial: inner ear inner ear (promontor(promontory of y of cochlea; cochlea; aka aka labyrinthine labyrinthine wall), facial wall), facial nervenerve

Posterior Posterior wall = wall = aditusaditus

Anterior Anterior wall = ET, wall = ET, canal of canal of tensor tensor tympani, tympani, ICAICA

IJ (superior IJ (superior bulb) in floor bulb) in floor of middle of middle earear

ICA in ICA in anterior wall anterior wall of middle of middle earear

StapediusStapedius

Inserts into the Inserts into the neck of stapesneck of stapes

FunctionFunction

Tensor TympaniTensor Tympani

Chorda TympaniChorda Tympani

5 mm superior to 5 mm superior to SM foramen enters SM foramen enters posterior iterposterior iter

From posterior iter From posterior iter into middle earinto middle ear

Enters anterior iter Enters anterior iter then leaves via then leaves via petrotympanic petrotympanic fissure fissure

Eustachian TubeEustachian TubePosterolateral 1/3 is bonyPosterolateral 1/3 is bony

Innervation: tympanic plexus and Innervation: tympanic plexus and fibers from pterygopalatine ganglionfibers from pterygopalatine ganglion

Inner EarInner Ear

Bony LabyrinthBony Labyrinth

CochleaCochlea

Semicircular Semicircular canalscanals

Membranous LabyrinthMembranous Labyrinth

Cochlear ductCochlear duct

Semicircular ductsSemicircular ducts

Utricle and saccule (within vestibule)Utricle and saccule (within vestibule)