Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
NECK PARTII • • • • LARYNX TRACHEA PHARYNX ESOPHAGUS THELARYNX THELARYNX-GENERALINFORMATION • Larynx:connec%onbetweenthepharynxandthetrachea • Preventsforeignbodiesfromenteringtheairways • Designedfortheproduc%onofsound(phona%on) • Shorterinwomenandchildren • Formedby9car%lages:3pairedand3unpaired • LocatedinthemidlineoppositetheC3-C6cervicalvertebrae Thesuperiorborderofthethyroidcar%lage:C3-C4junc<on Theinferiorendofthelarynx:C6vertebra THELARYNX RELATIONSOFTHELARYNX •Anterolateral-infrahyoidmuscles,platysma •Lateral-lobesofthethyroidgland,caro%dsheath •Posterior-itformstheanteriorwallofthelaryngopharynx •Superior-baseoftongueandvallecula •Inferior-trachea Theinfrahyoidmuscles: • sternohyoidandomohyoidliesuperficiallyand • sternothyroidandthyrohyoidliemoredeeply Thecaro<dsheath: • thecaro<darteriesmedially • theIJVlaterally • thevagusnerveposteriorly THELARYNX ThelarynxissuspendedfromthehyoidboneaboveandaLachedto thetracheabelowbymembranesandligaments. Thehyoidbonealsoprovidessupportforthethyrohyoidmembrane. THELARYNGEALSKELETON Theskeletalframeworkofthelarynxisformedbyaseriesofcar%lages interconnectedbyligamentsandfibrousmembranes,andmovedbya numberofmuscles THELARYNX ThereareTHREESINGLECARTILAGES: • thyroid • epigloOs • cricoidcar%lages andTHREEPAIREDCARTILAGES: • arytenoid • corniculate • cuneiformcar%lages THELARYNX–THESKELETON THYROIDCARTILAGE isthelargestofthelaryngealcar%lages. ItisformedbyarightandalePlamina,whicharewidelyseparated posteriorly,butconvergeandjoinanteriorly. Themostsuperiorpointofthesiteoffusionbetweenthetwobroad flatlaminaeprojectsforwardasthelaryngealprominence(Adam's apple). Theanglebetweenthetwolaminaeismoreacuteinmen(90°) thaninwomen(120°)sothelaryngealprominenceismoreapparentin menthanwomen. Justsuperiortothelaryngealprominence,thesuperiorthyroidnotch separatesthetwolaminaeastheydivergelaterally. Thereisalessdis%nctinferiorthyroidnotchinthemidlinealongthe baseofthethyroidcar%lage. THELARYNX–THESKELETON THYROIDCARTILAGE Theposteriormarginofeachlaminaofthethyroidcar%lageis elongatedtoformasuperiorhornandaninferiorhorn: ▪Themedialsurfaceoftheinferiorhornhasafacetforar%cula%on withthecricoidcar<lage. ▪Thesuperiorhornisconnectedbyalateralthyrohyoidligamentto theposteriorendofthegreaterhornofthehyoidbone. THELARYNX–THESKELETON EPIGLOTTIS TheepigloOsisaleaf-shapedcar%lageaLachedbyitsstemtothe posterioraspectofthethyroidcar%lageattheangle projectsposterosuperiorlyfromitsaLachmenttothethyroidcar%lage TheaLachmentisviathethyro-epigloUcligamentinthemidline approximatelymidwaybetweenthelaryngealprominenceandthe inferiorthyroidnotch. Normally,theepigloOsdivertsfoodandliquidsawayfromthe laryngealinletandintothelateralfoodchannels. Itisnotessen%alforrespira%onorphona%on. THELARYNX–THESKELETON CRICOIDCARTILAGE Thecricoidcar%lageisthemostinferiorofthelaryngealcar%lagesand completelyencirclestheairway Itisshapedlikeasignetringwithabroadlaminaofcricoidcar<lage posteriortotheairwayandamuchnarrowerarchofcricoidcar<lage circlinganteriorly. Thecricoidcar%lagehastwoar<cularfacetsoneachsidefor ar%cula%onwithotherlaryngealcar%lages: ▪Onefacetisontheslopingsuperolateralsurfaceofthelaminaand ar%culateswiththebaseofanarytenoidcar%lage. ▪Theotherfacetisonthelateralsurfaceofthelaminanearitsbase andisforar%cula%onwiththemedialsurfaceoftheinferiorhornof thethyroidcar%lage. THELARYNX–THESKELETON ARYTENOIDCARTILAGES Thetwoarytenoidcar%lagesarepyramid-shapedcar%lageswiththree surfaces,abaseofarytenoidcar<lageandanapexofarytenoid car<lage Thebaseisconcaveandar%culateswiththeslopingar%cularfaceton thesuperolateralsurfaceofthelaminaofcricoidcar%lage. Theapexar%culateswithacorniculatecar%lage. Themedialsurfaceofeachcar%lagefacestheother. THELARYNX–THESKELETON ARYTENOIDCARTILAGES Theanterolateralsurfacehastwodepressions,separatedbyaridge, formuscle(vocalis)andligament(ves%bularligament)aLachment. ARYTENOIDCARTILAGES Theanteriorangleofthebaseiselongatedintoavocalprocessto whichthevocalligamentisaLached. ARYTENOIDCARTILAGES Thelateralangleissimilarlyelongatedintoamuscularprocessfor aLachmentoftheposteriorandlateralcrico-arytenoidmuscles. THELARYNX–THESKELETON CORNICULATE Thecorniculatecar%lagesaretwosmallconicalcar%lageswhosebases ar%culatewiththeapicesofthearytenoidcar%lages. Theirapicesprojectposteromediallytowardeachother. CUNEIFORM Thesetwosmallclub-shapedcar%lageslieanteriortothecorniculate car%lagesandaresuspendedinthepartofthefibro-elas<cmembrane ofthelarynxthataLachesthearytenoidcar%lagestothelateral marginoftheepigloOs. THELARYNX–THELIGAMENTS EXTRINSICLIGAMENTS: • Thyrohyoidmembrane • Hyo-epigloOcligament • Cricotrachealligament INTRINSICLIGAMENTS: • Fibro-elas%cmembraneofthelarynx • Cricothyroidligament(cricovocalmembrane,cricothyroid membrane) • Quadrangularmembrane THELARYNX–THELIGAMENTS THYROHYOIDMEMBRANE Thethyrohyoidmembraneisatoughfibro-elas%cligamentthatspans betweenthesuperiormarginofthethyroidcar%lagebelowandthe hyoidboneabove. THYROHYOIDMEMBRANE Anapertureinthelateralpartofthethyrohyoidmembraneoneach sideisforthesuperiorlaryngealartery,theinternalbranchofthe superiorlaryngealnerveandlympha%cs. Theposteriorbordersofthethyrohyoidmembranearethickenedto formthelateralthyrohyoidligaments Themembraneisalsothickenedanteriorlyinthemidlinetoform themedianthyrohyoidligament THELARYNX–THELIGAMENTS HYO-EPIGLOTTICLIGAMENT Thehyo-epigloUcligamentextendsfromthemidlineoftheepigloOs, anterosuperiorlytothebodyofthehyoidbone. CRICOTRACHEALLIGAMENT Thecricotrachealligamentrunsfromthelowerborderofthecricoid car%lagetotheadjacentupperborderofthefirsttrachealcar%lage. THELARYNX–THELIGAMENTS FIBRO-ELASTICMEMBRANEOFTHELARYNX Thefibro-elas<cmembraneofthelarynxlinkstogetherthelaryngeal car%lagesandcompletesthearchitecturalframeworkofthelaryngeal cavity. FIBRO-ELASTICMEMBRANEOFTHELARYNX Itiscomposedoftwoparts: • alowercricothyroidligament • anupperquadrangularmembrane. THELARYNX–THELIGAMENTS CRICOTHYROIDLIGAMENT(CRICOVOCALMEMBRANE, CRICOTHYROIDMEMBRANE) ThecricothyroidligamentisaLachedtothearchofcricoidcar%lage andextendssuperiorlytoendinafreeuppermarginwithinthespace enclosedbythethyroidcar%lage. Oneachside,thisupperfreemarginaLaches: ▪anteriorlytothethyroidcar%lage,and ▪posteriorlytothevocalprocessesofthearytenoidcar%lages. ThefreemarginbetweenthesetwopointsofaLachmentisthickened toformthevocalligament,whichisunderthevocalfold(truevocal cord)ofthelarynx. Thecricothyroidligamentisalsothickenedanteriorlyinthemidlineto formadis%nctmediancricothyroidligament THELARYNX–THELIGAMENTS CRICOTHYROIDLIGAMENT(CRICOVOCALMEMBRANE, CRICOTHYROIDMEMBRANE) Themediancricothyroidligamentspansthedistancebetweenthe archofcricoidcar%lageandtheinferiorthyroidnotchandadjacent deepsurfaceofthethyroidcar%lageuptotheaLachmentofthevocal ligaments. THELARYNX–THELIGAMENTS QUADRANGULARMEMBRANE Thequadrangularmembraneoneachsiderunsbetweenthelateral marginoftheepigloOsandtheanterolateralsurfaceofthearytenoid car%lageonthesameside. ItisalsoaLachedtothecorniculatecar%lage,whichar%culateswith theapexofarytenoidcar%lage. Eachquadrangularmembranehasafreeuppermargin,betweenthe topoftheepigloOsandthecorniculatecar%lage,andafreelower margin. Thefreelowermarginisthickenedtoformtheves<bularligament undertheves<bularfold(falsevocalcord)ofthelarynx. Oneachside,theves%bularligamentofthequadrangularmembraneisseparated fromthevocalligamentofthecricothyroidligament belowbyagap. THELARYNX–THELARYNGEALJOINTS CRICOTHYROIDJOINTS Thejointbetweentheinferiorhornsofthethyroidcar%lageandthe cricoidcar%lageissynovialjoint. Eachissurroundedbyacapsuleandisreinforcedbyassociated ligaments.Thecricothyroidjointsenablethethyroidcar%lagetomove forwardand%ltdownwardonthecricoidcar%lage Thecricothyroidjointsenablethethyroidcar%lagetomoveforward and%ltdownwardonthecricoidcar%lage THELARYNX–THELARYNGEALJOINTS CRICO-ARYTENOIDJOINTS Thecrico-arytenoidjointsbetweenar%cularfacetsonthesuperolateral surfacesofthecricoidcar%lageandthebasesofthearytenoid car%lagesenablethearytenoidcar%lagestoslideawayortowardeach otherandtorotatesothatthevocalprocessespivoteithertowardor awayfromthemidline.Thesemovementsabductandadductthevocal ligaments. THELARYNX CAVITYOFTHELARYNX Thecentralcavityofthelarynxistubularandlinedbymucosa. Thesuperiorapertureofthecavity(laryngealinlet)opensintothe anterioraspectofthepharynxjustbelowandposteriortothetongue: ▪Itsanteriorborderisformedbymucosacoveringthesuperiormargin oftheepigloOs. ▪Itslateralbordersareformedbymucosalfolds(aryepigloUcfolds), whichenclosethesuperiormarginsofthequadrangularmembranes andadjacentsoP%ssues. ▪Itsposteriorborderinthemidlineisformedbyamucosalfoldthat formsadepression(interarytenoidnotch)betweenthetwo corniculatetubercles. THELARYNX DIVISIONINTOTHREEMAJORREGIONS Twopairsofmucosalfolds,theves%bularandvocalfolds,which projectmediallyfromthelateralwallsofthelaryngealcavity,constrict itanddivideitintothreemajorregions: • theves<bule • amiddlechamber • theinfragloUccavity ▪Theves<buleistheupperchamberofthelaryngealcavitybetween thelaryngealinletandtheves%bularfolds,whichenclosethe ves%bularligamentsandassociatedsoP%ssues. ▪Themiddlepartofthelaryngealcavityisverythinandisbetweenthe ves%bularfoldsaboveandthevocalfoldsbelow. ▪TheinfragloUcspaceisthemostinferiorchamberofthelaryngeal cavityandisbetweenthevocalfolds(whichenclosethevocal ligamentsandrelatedsoP%ssues)andtheinferioropeningofthe larynx. THELARYNX Laryngealventricle: recessesextendinglaterallyfromthemiddlepartofthelaryngeal cavitybetweenves%bularandvocalfolds. Laryngealsaccule Thelaryngealsacculeisablindpocketopeningintoeachventriclethat islinedwithmucosalglands.Mucussecretedintothesaccules lubricatesthevocalfolds. THELARYNX THERIMAVESTIBULI Whenviewedfromabovethereisatriangularopening(therima ves<buli)betweenthetwoadjacentves%bularfoldsattheentranceto themiddlechamberofthelaryngealcavity. THERIMAGLOTTIDIS Inferiortotheves%bularfolds,thevocalfolds(truevocalcords)and adjacentmucosa-coveredpartsofthearytenoidcar%lagesformthe lateralwallsofasimilar,butnarrowertriangularopening(therima gloUdisbetweenthetwoadjacentvocalfolds) THEGLOTTIS ThegloUs(thevocalapparatusofthelarynx)makesupthevocalfolds andprocesses,togetherwiththerimagloOdis,theaperturebetween thevocalfolds THELARYNX–THEMUSCLES THELARYNGEALMUSCLES Thelaryngealmusclesaredividedinto: • Extrinsiclaryngealmuscles • Intrinsiclaryngealmuscles THELARYNX–THEMUSCLES THELARYNGEALMUSCLES-EXTRINSIC Extrinsiclaryngealmusclesmovethelarynxasawhole. Theinfrahyoidmusclesaredepressorsofthehyoidandlarynx, whereasthesuprahyoidmusclesareelevatorsofthehyoidandlarynx. Thelarynxiselevatedbythe: • thyrohyoid • stylohyoid • mylohyoid • digastric • stylopharyngeus • palatopharyngeusmuscles • • • • Thelarynxisdepressedbythe: omohyoid sternohyoid sternothyroidmuscles THELARYNX–THEMUSCLES THELARYNGEALMUSCLES-INTRINSIC Theintrinsicmusclesofthelarynx: • adjusttensioninthevocalligaments, • openandclosetherimagloOdis, • controltheinnerdimensionsoftheves%bule, • closetherimaves%buli,and • facilitateclosingofthelaryngealinlet. Allbutoneoftheintrinsicmusclesaresuppliedbytheinferior laryngealnerve,branchoftherecurrentlaryngealnerve,(CNX). Thecricothyroidmuscleisinnervatedbythesuperiorlaryngealnerve. Thecricothyroidissuppliedbytheexternallaryngealnerve,oneofthe twoterminalbranchesofthesuperiorlaryngealnerve(frominferior vagalganglionoftheCNX). THELARYNX–THEMUSCLES THELARYNGEALMUSCLES-INTRINSIC Theac%onsoftheintrinsiclaryngealmusclesare: • adductorsandabductors, • sphincters, • tensorsandrelaxers. Adductorsandabductors:Thesemusclesmovethevocalfoldstoopen andclosetherimagloOdis. Theprincipaladductorsarethelateralcrico-arytenoidmuscles,which pullthemuscularprocessesanteriorly,rota%ngthearytenoidcar%lages sothattheirvocalprocessesswingmedially. Theabductorsaretheposteriorcrico-arytenoidmuscles,whichpullthe muscularprocessesposteriorly,rota%ngthevocalprocesseslaterally andthuswideningtherimagloOdis. THELARYNX–THEMUSCLES THELARYNGEALMUSCLES-INTRINSIC Sphincters:Thecombinedac%onsofmostofthemusclesofthe laryngealinletresultinasphinctericac%onthatclosesthelaryngeal inletasaprotec%vemechanismduringswallowing. Tensors:Theprincipaltensorsarethecricothyroidmuscles,which%lt orpulltheprominenceorangleofthethyroidcar%lageanteriorlyand inferiorlytowardthearchofthecricoidcar%lage. Relaxers:Theprincipalmusclesinthisgrouparethethyroarytenoid muscles,whichpullthearytenoidcar%lagesanteriorly,towardthe thyroidangle(prominence),therebyrelaxingthevocalligamentsto lowerthepitchofthevoice. THELARYNX–THEMUSCLES INNERVATION:THE RECURRENTLARYNGEAL NERVE THELARYNGEALMUSCLES-INTRINSIC Thevocalismuscleslie: • medialtothethyro-arytenoidmuscles • lateraltothevocalligamentswithinthevocalfolds. Thevocalismusclesproduceminuteadjustmentsofthevocal ligaments,selec%velytensingandrelaxingtheanteriorandposterior parts,respec%vely,ofthevocalfoldsduringanimatedspeechand singing. THELARYNX ARTERIESOFLARYNX Thelaryngealarteries,branchesofthesuperiorandinferiorthyroid arteries,supplythelarynx. Thesuperiorlaryngealartery(branchofthesuperiorthyroidartery fromexternalcaro%dartery)accompaniestheinternalbranchofthe superiorlaryngealnervethroughthethyrohyoidmembraneand branchestosupplytheinternalsurfaceofthelarynx. Thecricothyroidartery,asmallbranchofthesuperiorthyroidartery, suppliesthecricothyroidmuscle. Theinferiorlaryngealartery(branchoftheinferiorthyroidartery fromthyrocervicaltrunkofthesubclavianartery)accompaniesthe inferiorlaryngealnerve(terminalpartoftherecurrentlaryngeal nerve)andsuppliesthemucousmembraneandmusclesintheinferior partofthelarynx THELARYNX IMA(inferiormiddleartery)THYROIDARTERY Athyroidimaarteryarisesfromtheaor%carchorbrachiocephalic arteryandcoursestotheinferiorpor%onoftheisthmusorinferior thyroidpoles. Thyroidimaarteryisofsurgicalimportance;itcancause complica%onssuchasseverebleedinginsurgeryofthethorax, trachea,thyroidorparathyroidglands.Knowledgeofoccurrenceof thearteryisespeciallyimportantduringtracheostomyand thyroidectomy. THELARYNX VEINSOFLARYNX Veinsdrainingthelarynxaccompanythearteries: ▪Superiorlaryngealveinsdrainintosuperiorthyroidveins,whichin turndrainintotheinternaljugularveins ▪Inferiorlaryngealveinsdrainintoinferiorthyroidveins,whichdrain intothelePbrachiocephalicvein. THELARYNX LYMPHATICSOFLARYNX Lympha%csdrainregionsaboveandbelowthevocalfolds: ▪Thoseabovethevocalfoldsfollowthesuperiorlaryngealarteryand terminateinsuperiordeepcervicalnodesassociatedwiththe bifurca%onofthecommoncaro%dartery. ▪Thosebelowthevocalfoldsdrainintoinferiordeepcervicalnodes associatedwiththeinferiorthyroidarteryorwithnodesassociated withthefrontofthecricothyroidligamentoruppertrachea. ThegloOsisverypoorlyendowedwithlympha%cvessels;some95%of malignanttumoursconfinedtothegloOswillpresentonlywitha changeinvoiceorairwayobstruc%on,butwillnotshowsignsofspread toadjacentlymphnodesatpresenta%on. THELARYNX NERVESOFLARYNX Thenervesofthelarynxare: • thesuperiorlaryngealnerveand • theinferiorlaryngealnerve branchesofthevagusnerves(CNX). Thelarynxisinnervatedby: • theinternalandexternalbranchesofthesuperiorlaryngealnerve, • therecurrentlaryngealnerveand • sympathe<cnerves THELARYNX NERVESOFLARYNX Thesuperiorlaryngealnervearisesfromtheinferiorvagalganglionat thesuperiorendofthecaro%dtriangle. Branchesofthesuperiorlaryngealnerve: • internal • external laryngealnerves. Conven%onally,theinternallaryngealnerveisdescribedassensory, theexternallaryngealnerveasmotor, andtherecurrentlaryngealnerveasmixed. THELARYNX NERVESOFLARYNX Theinternallaryngealnerve,thelargeroftheterminalbranchesof thesuperiorlaryngealnerve,piercesthethyrohyoidmembranewith thesuperiorlaryngealartery,supplyingsensoryfiberstothe laryngealmucousmembraneofthe laryngealves%buleandmiddlelaryngealcavity,includingthe superiorsurfaceofthevocalfolds. Theexternallaryngealnerve,thesmallerterminalbranchofthe superiorlaryngealnerve,descendsposteriortothesternothyroid muscleincompanywiththesuperiorthyroidartery. Theinferiorlaryngealnerve,thecon%nua%onoftherecurrent laryngealnerve(abranchofthevagusnerve)entersthelarynxby passingdeeptotheinferiorborderoftheinferiorpharyngeal constrictorandmedialtothelaminaofthethyroidcar%lage. THELARYNX NERVESOFLARYNX Becausetheinferiorlaryngealnervesuppliesalltheintrinsicmuscles exceptthecricothyroid,theinferiorlaryngealnerveistheprimary motornerveofthelarynx. Thesuperiorlaryngealnerve(branchoftheinferiorvagalganglion) innervatesthecricothyroidmuscle,whichtensesthevocalcord,and innervatesmucosaabovethevocalfold. Theinferiorlaryngealnerve(branchoftherecurrentlaryngealnerve) innervatesallofthemusclesofthelarynxexceptforthecricothyroid andmucosabelowthevocalfold. AUTONOMICINNERVATIONOFLARYNX Parasympathe<csecretomotorfibresrunwithboththesuperiorand therecurrentlaryngealnervestomucousglands. Postganglionicsympathe<cfibresruntothelarynxwithexternal caro%dplexus;theyoriginateinthesuperiorandmiddlecervical ganglia. THETRACHEA Thetrachea,extendingfromthelarynxintothethorax,terminates inferiorlyasitdividesintorightandlePmainbronchi. Thetrachealcar<lageskeepthetracheapatent;theyaredeficient posteriorlywherethetracheaisadjacenttotheesophagus. Theposteriorgapsinthetrachealringsarespannedbytheinvoluntary trachealismuscle,smoothmuscleconnec%ngtheendsoftherings. Theposteriorwallofthetracheaisflat Thetracheaextendsfromtheinferiorendofthelarynxatthelevelof theC6vertebra.ItendsatthelevelofthesternalangleortheT4–T5 disc. THETRACHEA Lateraltothetracheaarethe commoncaro%darteriesand thelobesofthethyroidgland. Thebrachiocephalictrunk isrelatedtotherightside ofthetracheaintheroot oftheneck. Devia%onofthetracheafromthemidline,apparentsuperficiallyor radiographically,oPensignalsthepresenceofapathologicalprocess. THEPHARYNX Thepharynxisafibromusculartubethatconnectsthenasalcavity, oralcavity,andlarynx. Thepharynxissubdividedintothe: • nasopharynx • oropharynx • laryngopharynx Responsibleforproperlyconduc%ngfoodtotheesophagusandairto thelungs Composedof: •Threeconstrictormuscles •Threelongitudinalmuscles •Car%laginouspartofthe pharyngotympanictube •SoPpalate THEPHARYNX Basedontheseanteriorrela%onshipsthepharynxissubdividedinto threeregions,thenasopharynx,oropharynx,andlaryngopharynx: ▪Theposteriorapertures(choanae)ofthenasalcavi%esopeninto thenasopharynx. ▪Theposterioropeningoftheoralcavity(oropharyngealisthmus) opensintotheoropharynx. ▪Thesuperiorapertureofthelarynx(laryngealinlet)opensinto thelaryngopharynx. THEPHARYNX THENASOPHARYNX–THEBOUNDARIES • Roof-fornix • Floor-soPpalate • Anterior-choanaeofthenasalcavity • Posterior-mucosacoveringsuperiorconstrictor • Lateral-mucosacoveringsuperiorconstrictor Os<umoftheauditorytubeopensintothenasopharynx. Theauditorytubeallowsspreadofinfec%onsbetweenthemiddleear andthenasopharynx. Thepharyngealtonsil(adenoid)isonthesuperiorwallofthe nasopharynx. THEPHARYNX THEOROPHARYNX TheoropharynxliesbetweenthesoPpalateandthe%pofthe epigloOs. THEOROPHARYNX–THEBOUNDARIES • Superior-nasopharynx • Inferior-posterior1/3ofthetongue • Anterior-palatoglossalfoldoftheoralcavity • Posterior-mucosacoveringthesuperiorandmiddleconstrictor mm. • Lateral-mucosacoveringthesuperiorandmiddleconstrictors Pala<netonsilsarelocatedintheoropharynxbetweenthe palatoglossalandpalatopharyngealfolds EpigloUcvalleculaisthedepressionimmediatelyposteriortotheroot ofthetongue THEPHARYNX THELARYNGOPHARYNX–THEBOUNDARIES • Superior-oropharynx • Anterior-larynxandepigloOs • Posterior-mucosacoveringmiddleandinferiorconstrictormm. • Lateral-mucosacoveringmiddleandinferiorconstrictors Thepiriformfossa(recess)isasmalldepressionlocatedonthelateral wallofthelaryngopharyngealcavityoneithersideoftheentranceto thelarynx Thepiriformfossa(recess)isapoten%alloca%onforobjectsto becomelodged Branchesoftheinternallaryngealandrecurrentlaryngealnerveslie deeptothemucousmembraneofthepiriformfossaandare vulnerabletoinjurywhenaforeignbodylodgesinthefossa. THEPHARYNX THELARYNGOPHARYNX Anteriorly,itcommunicateswiththelarynxthroughthelaryngealinlet (aditus). Thepharynxisseparatedfromtheposteriorlyposi%onedvertebral columnbyathinretropharyngealspacecontaininglooseconnec%ve %ssue. THEPHARYNX THEMUSCLESOFTHEPHARYNX Themusclesofthepharynxareorganizedintotwogroupsbasedon theorienta%onofmusclefibers. Theconstrictormuscleshavefibersorientedinacirculardirec%on rela%vetothepharyngealwall,whereasthelongitudinalmuscleshave fibersorientedver%cally. THEMUSCLESOFTHEPHARYNX: • theconstrictormuscles • thelongitudinalmuscles THEPHARYNX THECONSTRICTORMUSCLESOFTHEPHARYNX Theexternalcircularlayerofpharyngealmusclesconsistsofthree pharyngealconstrictors: • superior, • middle, • inferior. Posteriorly,theconstrictormusclesfromeachsidearejoinedtogether bythepharyngealraphe Anteriorly,thesemusclesaLachtobonesandligamentsrelatedtothe lateralmarginsofthenasalandoralcavi%esandthelarynx. Whentheconstrictormusclescontractsequen%allyfromtopto boLom,asinswallowing,theymoveabolusoffoodthroughthe pharynxandintotheesophagus. Alloftheconstrictorsareinnervatedbythepharyngealbranch ofthevagusnerve[CNX]. THEPHARYNX THELONGITUDINALMUSCLESOFTHEPHARYNX Theinternallongitudinalmusclesarenamedaccordingtotheir origins: • palatopharyngeus • stylopharyngeus • salpingopharyngeus Thestylopharyngeusfromthestyloidprocessofthetemporalbone Thesalpingopharyngeus,fromthecar%laginouspartofthe pharyngotympanictube(salpinxisGreekfor“tube”) ThepalatopharyngeusfromthesoPpalate(thepalatopharyngeal archposteriortothepala%netonsil). THEPHARYNX THELONGITUDINALMUSCLESOFTHEPHARYNX • Stylopharyngeus-glossopharyngealnerve[IX] • Salpingopharyngeus-vagusnerve[X] • Palatopharyngeus-vagusnerve[X] Thelongitudinalmuscleselevatethepharyngealwall,orduring swallowing,pullthepharyngealwallupandoverabolusoffood beingmovedthroughthepharynxandintotheesophagus. THEPHARYNX THEFASCIAOFTHEPHARYNX Thepharyngealfasciaisseparatedintotwolayers,whichsandwich thepharyngealmusclesbetweenthem: ▪Athinlayer(buccopharyngealfascia)coatstheoutsideofthe muscularpartofthewallandisacomponentofthepretracheal layerofcervicalfascia ▪Amuchthickerlayer(pharyngobasilarfascia)linestheinner surface. THEPHARYNX GAPSINTHEPHARYNGEALWALL Gapsbetweenmusclesofthepharyngealwallprovideimportant routesformusclesandneurovascular%ssues GAPSINTHEPHARYNGEALWALL Oneofthelargestandmostimportantaperturesinthepharyngeal wallisbetweenthesuperiorandmiddleconstrictormusclesofthe pharynxandtheposteriorborderofthemylohyoidmuscle,which formsthefloorofthemouth Theoropharyngealtriangle allowsmuscles,nerves,andvesselstopassbetweenregionslateral tothepharyngealwallandtheoralcavity,par%cularlytothe tongue. THEPHARYNX GAPSINTHEPHARYNGEALWALL Thegapbetweenthemiddleandinferiorconstrictormusclesallows theinternallaryngealvesselsandnerveaccesstotheapertureinthe thyrohyoidmembranetoenterthelarynx. Therecurrentlaryngealnervesandaccompanyinginferiorlaryngeal vesselsenterthelarynxposteriortotheinferiorhornofthethyroid car%lagedeeptotheinferiormarginoftheinferiorconstrictor muscle. THEPHARYNX THECONTENTSOFTHEGAPSINTHEPHARYNGEALWALL Superiortothesuperiorpharyngealconstrictor: • thelevatorvelipala<ni, • pharyngotympanictube,and • ascendingpala<neartery passthroughagapbetweenthesuperiorpharyngealconstrictor andthecranium.Itisherethatthepharyngobasilarfasciablends withthebuccopharyngealfasciatoform,withthemucous membrane,thethinwallofthepharyngealrecess. THEPHARYNX THECONTENTSOFTHEGAPSINTHEPHARYNGEALWALL Agapbetweenthesuperiorandmiddlepharyngealconstrictors formsapassagewaythatallows: • thestylopharyngeus, • glossopharyngealnerve,and • stylohyoidligament topasstotheinternalaspectofthepharyngealwall THEPHARYNX THECONTENTSOFTHEGAPSINTHEPHARYNGEALWALL Agapbetweenthemiddleandinferiorpharyngealconstrictors allows: • theinternallaryngealnerveand • superiorlaryngealarteryandvein topasstothelarynx. THEPHARYNX THECONTENTSOFTHEGAPSINTHEPHARYNGEALWALL Agapinferiortotheinferiorpharyngealconstrictorallows: • therecurrentlaryngealnerveand • inferiorlaryngealartery topasssuperiorlyintothelarynx. THEPHARYNX ARTERIES Bloodsupplytothepharynxisbybranchesoftheexternalcaro%d artery: • ascendingpharyngeal, • superiorthyroid, • lingual, • facial, • maxillaryarteries. VEINS Venousdrainageofthepharynxisthroughthepharyngealplexuson theposterioraspectofthepharynx. Blooddrainsfromheretotheinternaljugularvein. THEPHARYNX LYMPHATICS Lympha%cdrainageistotheretropharyngealanddeepcervicalnodes. NERVES Sensoryandmotorinnerva%ontothepharynxoriginatesfromthe pharyngealplexusontheposterioraspectofthepharyngeal constrictors. Thisplexusisformedbypharyngealbranchesofthevagus[X]and glossopharyngeal[IX]nervesandbypostganglionicsympathe<c nervefibersfromthesuperiorcervicalganglion. THEPHARYNX Thepharyngealplexusisformedby: ▪thepharyngealbranchofthevagusnerve[X], ▪branchesfromtheexternallaryngealnervefromthesuperior laryngealbranchofthevagusnerve[X],and ▪pharyngealbranchesoftheglossopharyngealnerve[IX]. Motorfibersintheplexusarederivedfromthecranialpartofthe accessorynerve[XI],whichrunswiththevagusnerve[X]andsupplies allmusclesofthepharynx,larynx,andsoPpalateexceptforthe tensorvelipala%niandstylopharyngeusmuscles,whichare innervatedbythetrigeminal[V]andglossopharyngeal[IX]nerves, respec%vely. THEPHARYNX NERVES Sensoryinnerva<onofthepharynxisfromtheglossopharyngeal nerve[IX]. Themaxillary[V2]andvagus[X]nervesalsocarrysensa%onfroma smallpartofthepharynx. THEPHARYNX SENSORYINNERVATIONOFTHEPHARYNX Eachsubdivisionofthepharynxhasadifferentsensoryinnerva%on: ▪Thenasopharynxisinnervatedbyapharyngealbranchofthe maxillarynerve[V2]thatoriginatesinthepterygopala%nefossaand passesthroughthepalatovaginalcanalinthesphenoidbonetoreach theroofofthepharynx. ▪Theoropharynxisinnervatedbytheglossopharyngealnerve[IX]via thepharyngealplexus. ▪Thelaryngopharynxisinnervatedbythevagusnerve[X]viathe internalbranchofthesuperiorlaryngealartery. THEESOPHAGUS Theesophagusisamusculartubethatconnectsthepharynx tothestomach.Itbeginsintheneckwhereitiscon%nuous withthelaryngopharynxatthepharyngo-esophagealjunc<on. Theesophagusconsistsofstriated(voluntary)muscleinitsupper third,smooth(involuntary)muscleinitslowerthird,andamixtureof striatedandsmoothmuscleinbetween. Ontherightoftheesophagusistherightlobeofthethyroidglandand therightcaro%dsheathanditscontents. Therecurrentlaryngealnerveslieinornearthetracheo-esophageal groovesbetweenthetracheaandtheesophagus Thecervicalpartoftheesophagusissuppliedbythebranchesofthe inferiorthyroidarteries. THEESOPHAGUS Thecervicalesophagusreceives: • soma<cfibersviabranchesfromtherecurrentlaryngealnerves • vasomotorfibersfromthecervicalsympathe%ctrunksthroughthe plexusaroundtheinferiorthyroidartery Themotorfibersofthephrenicnervesupplythediaphragm THELYMPHATICOFTHENECK Mostsuperficial%ssuesintheneckaredrainedbylympha%cvessels thatenterthesuperficialcervicallymphnodes,whicharelocated alongthecourseoftheEJV. Lymphfromthesenodes,likelymphfromalloftheheadandneck, drainsintoinferiordeepcervicallymphnodes. Mostlymphfromthesixtoeightlymphnodesthendrainsintothe supraclaviculargroupofnodes,whichaccompanythecervicodorsal trunk. ThemaingroupofdeepcervicalnodesformsachainalongtheIJV, mostlyundercoveroftheSCM THELYMPHATICOFTHENECK Efferentlympha%cvesselsfromthedeepcervicalnodesjointoform thejugularlympha<ctrunks,whichusuallyjointhethoracicduct Thethoracicductpassessuperiorlythroughthesuperiorthoracic aperturealongthelePborderoftheesophagus. Itarcheslaterallyintherootoftheneck,posteriortothecaro%d sheathandanteriortothesympathe%ctrunkandvertebraland subclavianarteries Thethoracicductentersthelebbrachiocephalicveinatthejunc%on ofthesubclavianandIJVs(lebvenousangle).