THENECKPARTI
BONESANDJOINTSOFTHENECKMUSCLESOFTHENECK–SCM
CAROTIDTRIANGLEENDOCRINELAYEROFTHECERVICALVISCERA
Theneckhasfourmajorcompartments,whichareenclosedbyanoutermusculofascialcollar:• Thevertebralcompartmentcontainsthecervicalvertebraeand
associatedposturalmuscles.• Thevisceralcompartmentcontainsimportantglands(thyroid,
parathyroid,andthymus),andpartsoftherespiratoryanddigesRvetractsthatpassbetweentheheadandthorax.
• Thetwovascularcompartments,oneoneachside,containthemajorbloodvesselsandthevagusnerve.
THENECKTHENECK
TheanteriorporRonoftheneckcontainsthemajorvisceralstructuresbetweentheheadandthethorax:• pharynx• larynx• trachea• esophagus• thyroidandparathyroidglands
THENECKTHENECK
Theskeletonoftheneckisformedby:• thecervicalvertebrae,• hyoidbone,• manubriumofthesternum,• clavicles
THENECKTHENECK–THECERVICALVERTEBRAE
Thesevencervicalvertebraehavetransverseforamina(forthevertebralarteriestopassthrough)withintheir
transverseprocesses
THECERVICALVERTEBRAETHENECK–THECERVICALVERTEBRAE
VERTEBRALARTERIESThesevesselsentertheforamentransversarium
ofthe6thcervicalvertebra,emergingabovethe1st
cervicalvertebratoenterthesuboccipitaltriangle
ThemostdisRncRvefeatureofeachcervicalvertebraistheovalforamentransversarium(transverseforamen)inthe
transverseprocess.
Thereare7cervicalvertebrae:• the4typicalcervicalvertebraeC3–C6• the3atypicalcervicalvertebrae(C1,C2,andC7)
THENECK–THECERVICALVERTEBRAE
THECERVICALVERTEBRAE
ThefourtypicalcervicalvertebraeC3–C6havethefollowingcharacterisRcs:• Thevertebralbodyissmallandlongerfromsidetosidethan
anteroposteriorly;thesuperiorsurfaceisconcave,andtheinferiorsurfaceisconvex.
• Thevertebralforamenislargeandtriangular.• Thetransverseprocessesofallcervicalvertebrae(typicalor
atypical)includeforaminatransversariaforthevertebralvessels(thevertebralveinsand,exceptforvertebraC7,thevertebralarteries).
• Theirspinousprocessesareshortandbifid.
Thevertebralarteriesandtheiraccompanyingveinspassthroughthetransverseforamina,exceptthoseinC7,whichtransmitonlysmallaccessoryveins.
THENECK–THECERVICALVERTEBRAE
THECERVICALVERTEBRAE
Thefirst(C1,atlas),second(C2,axis)andseventh(C7,vertebraprominens)cervicalvertebraeareatypical.VertebraeC3–C6arethetypicalcervicalvertebrae.
Therearethreeatypicalcervicalvertebrae(C1,C2,andC7):• TheC1vertebraoratlas:aring-like,kidney-shapedbonelackinga
spinousprocessorbodyandconsisRngoftwolateralmassesconnectedbyanteriorandposteriorarches.ItsconcavesuperiorarRcularfacetsreceivetheoccipitalcondyles.
• TheC2vertebraoraxis:apeg-likedens(odontoidprocess)projectssuperiorlyfromitsbody.
• Thevertebraprominens(C7):so-namedbecauseofitslongspinousprocess,whichisnotbifid.Itstransverseprocessesarelarge,butitsforaminatransversariaaresmall.
THENECK–THECERVICALVERTEBRAE
THECERVICALVERTEBRAE
ThehyoidisuniqueamongbonesforitsisolaPonfromtheremainderoftheskeleton.
THENECK–THEHYOIDBONE
THEHYOIDBONE
Itissuspendedfromthestyloidprocessesofthetemporalbonesbythestylohyoidligaments
andisfirmlyboundtothethyroidcarPlage.
FuncRonally,thehyoidservesasana_achment
foranteriorneckmusclesandaproptokeeptheairwayopen.
ThehyoidliesintheanteriorpartoftheneckattheleveloftheC3
vertebra.
ThebodyofthehyoidEachendofitsbodyisunitedtoagreaterhornthatprojectsposterosuperiorlyandlaterallyfromthebody.EachlesserhornisasmallbonyprojecRon.
THENECK–THEHYOIDBONE
THEHYOIDBONEC3-levelofbodyofhyoid
FRACTUREOFHYOIDBONEItoccursinpeoplewhoaremanuallystrangledbycompressionofthethroat.ThisresultsindepressionofthebodyofthehyoidontothethyroidcarPlage.InabilitytoelevatethehyoidandmoveitanteriorlybeneaththetonguemakesswallowingandmaintenanceoftheseparaRonofthealimentaryandrespiratorytractsdifficultandmayresultinaspiraPonpneumonia.
Thehyoidboneissuspendedfromthestyloidprocessesbythestylohyoidligamentsandgivesa_achmentto• thesuprahyoidmusclesand• theinfrahyoidmuscles.
THENECK–THEHYOIDBONE
THEHYOIDBONE
Thesuprahyoidmusclesraisethehyoidbonetowardastabilizedmandibleduringswallowing.
Thesuprahyoidregioncontains4muscles:• Mylohyoid(V3)• Digastric(V3+VII)• Stylohyoid(VII)• Geniohyoid(C1-C2)
TheinfrahyoidmusclesdepressthehyoidboneandlarynxduringswallowingandvocalizaRon.
THENECK–THEHYOIDBONE
THEHYOIDBONE
Theinfrahyoidregioncontains4musclescommonlycalledstrapmuscles:• Omohyoid• Sternohyoid• Sternothyroid• Thyrohyoid
INNERVATION:cervical
plexus(C1–C3)
Theinfrahyoidmusclesareorganizedsothat:• sternohyoidandomohyoidliesuperficiallyand• sternothyroidandthyrohyoidliemoredeeply
THENECK–THEHYOIDBONE
THESUPRAHYOIDANDINFRAHYOIDREGIONSThesuprahyoidregioncontains4muscles:• Mylohyoid(V3)• Digastric(V3+VII)• Stylohyoid(VII)• Geniohyoid(C1viahypoglossalnerve(CNXII))Theinfrahyoidregioncontains4musclescommonlycalledstrapmuscles:• Omohyoid• Sternohyoid• Sternothyroid• Thyrohyoid
cervicalplexus(C1–C3)
Digastric Anteriorbelly:mylohyoidnerve,V3 Posteriorbelly:facialnerve,CNVII
Mylohyoid Mylohyoidnerve,V3 Stylohyoid Facialnerve,CNVII
THENECK–THEHYOIDBONE
THEHYOIDMUSCLES
Thecervicalplexus,composedoftheventralramiofC1-C4,innervatesmostoftheneckmusclesandprovidessensory
innervaRontotheanteriorandlateralneck
THENECK–THECERVICALPLEXUS
THECERVICALPLEXUSThecervicalplexus,composedoftheventralramiofC1-C4,innervatesmostoftheneckmusclesandprovidessensory
innervaRontotheanteriorandlateralneck.
The(spinal)accessorynerve(CNXI)exitsthejugularforamenandcrossestheposteriortriangle,
innervaRngtheSCMandtrapeziusmuscles
THENECK–THECERVICALPLEXUS
THECERVICALPLEXUSAddiRonalinnervaRonincludes:• Themylohyoidnerve(CNV3)innervatesthemylohyoidmuscle
andanteriorbellyofthedigastricmusclebeneaththechin.• Thefacialnerve(CNVII)innervatestheplatysmamusclethrough
itscervicalbranchandposteriorbellyofthedigastricmuscle.• Theglossopharyngealnerve(CNIX)suppliesthecaroRdbodyand
sinus(visceralsensory).• Thevagusnerve(CNX)suppliesthelarynxthroughitssuperior
andrecurrent(inferior)laryngealnerves.• Thehypoglossalnerve(CNXII)loopsthroughtheneckto
innervatethetongue.
ThefasciaoftheneckismulRlayeredandenclosesthemuscles,glands,andneurovascularstructures.
TherelaRonshipsbetweenthedifferentfasciallayersdeterminehowinfecPonandcancerspreadintheneck.
THENECK–THEFACIAOFTHENECK
THEFACIAOFTHENECK
FACIAOFTHENECK• THECERVICALSUBCUTANEOUSTISSUE• THEPLATYSMA
• THEDEEPCERVICALFASCIA• THEINVESTINGLAYEROFDEEPCERVICALFASCIA• THEPRETRACHEALLAYEROFDEEPCERVICALFASCIA• THEPREVERTEBRALLAYEROFDEEPCERVICALFASCIA
TheneckissurroundedbythecervicalsubcutaneousPssue/thesuperficialcervicalfascia
thatliesdeeptotheskinandinveststheplatysmamuscle.
THENECK–THEFACIAOFTHENECK
THECERVICALSUBCUTANEOUSTISSUE
ThecervicalsubcutaneousPssue/thesuperficialcervicalfascialiesbetweenthedermisoftheskinandtheinvesRnglayerofdeep
cervicalfascia
Itcontainscutaneousnerves,bloodandlymphaRcvessels,superficiallymphnodes,andvariableamountsoffat.
Anterolaterally,itcontainstheplatysma.
Theplatysmacoverstheanterolateralaspectoftheneck.Itderivedfrommesenchymeinthe2ndpharyngealarchoftheembryo,issuppliedbycervicalbranchofthefacialnerve,CNVII
FACIAOFTHENECK• THECERVICALSUBCUTANEOUSTISSUE• THEPLATYSMA
• THEDEEPCERVICALFASCIA• THEINVESTINGLAYEROFDEEPCERVICALFASCIA• THEPRETRACHEALLAYEROFDEEPCERVICALFASCIA• THEPREVERTEBRALLAYEROFDEEPCERVICALFASCIA
Thedeepcervicalfasciaconsistsofthreefasciallayers(sheaths):• invesPng,whichsurroundsallstructuresintheneck• pretracheal,whichenclosesthevisceraoftheneck• prevertebral,whichsurroundsthevertebralcolumnandthedeep
musclesassociatedwiththeback
THENECK–THEFACIAOFTHENECK
THEDEEPCERVICALFACIA
Thedeepcervicalfasciasubdividestheneckinto• vascular(caroPdsheath)• vertebral• visceralcompartments
Thisarrangementallowsmovementbetweenadjacentstructuresandcompartmentsandfacilitatesthesurgicalapproachtospecificareas.Theylimitthespreadofabscesses(collecRonsofpus)resulRngfrom
infecRons.
FACIAOFTHENECK• THECERVICALSUBCUTANEOUSTISSUE• THEPLATYSMA
• THEDEEPCERVICALFASCIA• THEINVESTINGLAYEROFDEEPCERVICALFASCIA• THEPRETRACHEALLAYEROFDEEPCERVICALFASCIA• THEPREVERTEBRALLAYEROFDEEPCERVICALFASCIA
Themostsuperficialdeepfasciallayer.CompletelysurroundstheenRreneckdeeptotheskinandsubcutaneousRssue.
THENECK–THEFACIAOFTHENECK
THEINVESTINGLAYEROFTHEDEEPCERVICALFACIA
TheinvesPnglayerofcervicalfasciaencirclesallstructuresoftheneckbyinvesRngthesternocleidomastoidandtrapeziusmuscles,thefascialroofsoftheanteriorandposteriorcervicaltriangles,andtheparoRdandsubmandibularsalivaryglands.
• splitsagaintosurroundthesternocleidomastoidmuscle,
THENECK–THEFACIAOFTHENECK
THEINVESTINGLAYEROFTHEDEEPCERVICALFACIA• A_achingposteriorlytotheligamentumnuchae
andthespinousprocessoftheCVIIvertebra,• thisfasciallayersplitsasitpassesforwardtoenclosethetrapezius
muscle,• reunitesintoasinglelayerasitformstheroofoftheposterior
triangle,
• andreunitesagaintojoinitstwinfromtheotherside.
Superiorly,theinvesRng(orsuperficial)layerofdeepcervicalfasciaa_achestothe:• Superiornuchallinesoftheoccipitalbone• Mastoidprocessesofthetemporalbones• ZygomaRcarches• Inferiorborderofthemandible• Hyoidbone• Spinousprocessesofthecervicalvertebrae
THENECK–THEFACIAOFTHENECK
THEINVESTINGLAYEROFTHEDEEPCERVICALFACIA
Justinferiortoitsa_achmenttothemandible,thefasciasplitstoenclosethesubmandibulargland;Posteriortothemandible,itsplitstoformthefibrouscapsuleoftheparoRdgland.
Inferiorly,theinvesRnglayerofdeepcervicalfasciaa_achestothemanubrium,clavicles,andacromionsandspinesofthescapula.
FACIAOFTHENECK• THECERVICALSUBCUTANEOUSTISSUE• THEPLATYSMA
• THEDEEPCERVICALFASCIA• THEINVESTINGLAYEROFDEEPCERVICALFASCIA• THEPRETRACHEALLAYEROFDEEPCERVICALFASCIA• THEPREVERTEBRALLAYEROFDEEPCERVICALFASCIA
Itislimitedtotheanteriorpartoftheneck.Itextendsinferiorlyfromthehyoidintothethorax,whereitblendswiththefibrouspericardiumcoveringtheheart.
THENECK–THEFACIAOFTHENECK
THEPRETRACHEALLAYEROFDEEPCERVICALFASCIA
Thepretracheallayeroffasciaincludesathinmuscularpart,whichenclosestheinfrahyoidmuscles,andavisceralpart,whichenclosesthethyroidgland,trachea,andesophagus
ItisconRnuousposteriorlyandsuperiorlywiththebuccopharyngealfasciaofthepharynx.
Thebuccopharyngealfasciaextendsfromthebaseoftheskullandenvelopsthebuccinatormuscleandpharyngealconstrictors
FACIAOFTHENECK• THECERVICALSUBCUTANEOUSTISSUE• THEPLATYSMA
• THEDEEPCERVICALFASCIA• THEINVESTINGLAYEROFDEEPCERVICALFASCIA• THEPRETRACHEALLAYEROFDEEPCERVICALFASCIA• THEPREVERTEBRALLAYEROFDEEPCERVICAL
FASCIA
Theprevertebrallayerofdeepcervicalfasciaformsatubularsheathforthevertebralcolumnandthemusclesassociatedwithit.
THENECK–THEFACIAOFTHENECK
THEPREVERTEBRALLAYEROFDEEPCERVICALFASCIA
Theprevertebrallayerofdeepfasciaisfixedtothecranialbasesuperiorly.
Inferiorly,itblendswiththeendothoracicfasciaperipherally
TheprevertebralfasciainananterolateralposiRonextendsfromtheanteriorandmiddlescalenemusclestosurroundthebrachialplexusandsubclavianarteryasthesestructurespassintotheaxilla.Thisfascialextensionistheaxillarysheath
ThecaroPdsheathisacolumnoffasciathatsurroundsthecommoncaroRdartery,theinternalcaroRdartery,theinternaljugularvein,andthevagusnerveasthesestructurespassthroughtheneck
ThecaroPdsheathcontainsthe:• CommonandinternalcaroRdarteries• Internaljugularvein• Vagusnerve(CNX)• Somedeepcervicallymphnodes• CaroRdsinusnerve• SympatheRcnervefibers(caroRdperiarterialplexuses)
THENECK–THEFACIAOFTHENECK
THEPREVERTEBRALLAYEROFDEEPCERVICALFASCIA
Theretropharyngealspaceisthelargestandmostimportantinterfascialspaceintheneck.
TheretropharyngealspaceisapotenPalspacethatconsistsoflooseconnecRveRssuebetweenthevisceralpartoftheprevertebrallayerofdeepcervicalfasciaandthebuccopharyngealfasciasurroundingthepharynxsuperficially.
SUPERFICIALSTRUCTURESOFTHENECK• CERVICALREGIONS/TRIANGLESANDCONTENTS• CUTANEOUSANDSUPERFICIALMUSCLESOFNECK• ARTERIESINCERVICALREGION• VEINSINCERVICALREGION• NERVESINCERVICALREGION• LYMPHNODESINCERVICALREGION
Theneckisdividedintofourmajorregionsbasedontheusuallyvisibleand/orpalpablebordersofthelargeandrelaRvelysuperficialSCMandtrapeziusmuscles:• Sternocleidomastoidregion• Posteriorcervicalregion• Lateralcervicalregion(posteriortriangle)• Anteriorcervicalregion(anteriortriangle)
THENECK–THECERVICALREGIONS
THECERVICALTRIANGLES
Theneckisdividedinto:• Sternocleidomastoidregion• Posteriorcervicalregion• Lateralcervicalregion(posteriortriangle)• Anteriorcervicalregion(anteriortriangle)
Theneckisdividedinto:• Sternocleidomastoidregion• Posteriorcervicalregion• Lateralcervicalregion(posteriortriangle)• Anteriorcervicalregion(anteriortriangle)
THENECK–THECERVICALREGIONS
THECERVICALTRIANGLES
THENECK–THECERVICALREGIONS
THESTERNOCLEIDOMASTOIDREGIONTheSCMvisiblydivideseachsideoftheneckintotheanteriorandlateralcervicalregions(anteriorandposteriortriangles).
MAINCONTENT:• sternocleidomastoidmuscle• superiorpartofexternaljugularvein• greaterauricularnerve• transversecervicalnerve
Thetwoheads(clavicleandsternal)oftheSCMareseparatedinferiorlybyaspace,visiblesuperficiallyasasmalltriangular
depression,thelessersupraclavicularfossa.
THENECK–THECERVICALREGIONS
THESTERNOCLEIDOMASTOIDREGION
• inferiorpartofinternaljugularveinMAINCONTENTOFTHELESSERSUPRACLAVICULARFOSSA
Thesuperiora_achmentoftheSCMisthemastoidprocessofthetemporalboneandthesuperiornuchallineoftheoccipitalbone.
INNERVATIONOFtheSCMs:• Spinalaccessorynerve(CNXI,motor)• C2andC3nerves(painandpropriocepRon)
THENECK–THECERVICALREGIONS
THESTERNOCLEIDOMASTOIDREGIONAcRngbilaterally,theSCMscanflextheneck.
AcRngunilaterally,theSCMlaterallyflexestheneck(bendsthenecksideways)androtatestheheadsotheearapproachestheshoulderoftheipsilateral(same)sidewhilerotaRngtheheadsothatthechinisturnedtowardthecontralateral(opposite)sideandelevates.
TotesttheSCM:theheadisturnedtotheoppositesideagainstresistance(handagainstchin).
THENECK–THECERVICALREGIONS
THEPOSTERIORCERVICALREGIONBORDERSofthesuboccipitaltriangle:•ObliquuscapiRssuperior•ObliquuscapiRsinferior•RectuscapiRsposteriormajor
• trapeziusmuscle• cutaneousbranchesofposteriorramiofcervicalspinalnerves
suboccipitalregionortriangleliesdeeptosuperiorpartofthisregion
MAINCONTENTS:
INNERVATIONOFTHETAPEZIUS:Spinalaccessoryn.alsoreceivessomebranchesfromC2andC3,thoughttobepropriocepRve
Ifthetrapeziusisparalyzed,theshoulderdroops
THENECK–THECERVICALREGIONS
THELATERALCERVICALREGIONThelateralcervicalregion(posteriortriangle)isbounded:• anteriorlybytheposteriorborderoftheSCM• posteriorlybytheanteriorborderofthetrapezius• inferiorlybythemiddlethirdoftheclaviclebetweenthetrapezius
andtheSCM• byanapex,wheretheSCMandtrapeziusmeetonthesuperior
nuchallineoftheoccipitalbone• byaroof,formedbytheinvesRnglayerofdeepcervicalfascia• byafloor,formedbymusclescoveredbytheprevertebrallayerof
deepcervicalfascia
THENECK–THECERVICALREGIONS
THELATERALCERVICALREGIONThelateralcervicalregionisdividedinto:• alargeOCCIPITALTRIANGLEsuperiorlyand• asmallOMOCLAVICULARTRIANGLEinferiorlybytheinferiorbelly
oftheomohyoid
TheOCCIPITALTRIANGLEissocalledbecausetheoccipitalarteryappearsinitsapex.Themostimportantnervecrossingtheoccipitaltriangleisthespinalaccessorynerve(CNXI).
• partofexternaljugularvein(EJV)• posteriorbranchesofcervicalplexusofnerves• spinalaccessorynerve(CNXI)• trunksofbrachialplexus• cervicodorsaltrunk• cervicallymphnodes
MAINCONTENTSOFTHEOCCIPITALTRIANGLE:
THENECK–THECERVICALREGIONS
THELATERALCERVICALREGION
• subclavianartery(thirdpart)• partofsubclavianvein(someRmes)• suprascapularartery• supraclavicularlymphnodes
MAINCONTENTSOFTHEOMOCLAVICULAR(SUBCLAVIAN)TRIANGLE:
TheinferiorpartoftheEJVcrossesthistrianglesuperficially;thesubclavianarteryliesdeepinit
THENECK–THECERVICALREGIONS
THEANTERIORCERVICALREGIONTheanteriorcervicalregion(anteriortriangle)hasthefollowing:• ananteriorboundaryformedbythemedianlineoftheneck• aposteriorboundaryformedbytheanteriorborderoftheSCM• asuperiorboundaryformedbytheinferiorborderofthemandible• anapexlocatedatthejugularnotchinthemanubrium• aroofformedbysubcutaneousRssuecontainingtheplatysma• afloorformedbythepharynx,larynx,andthyroidgland
THENECK–THECERVICALREGIONS
THEANTERIORCERVICALREGIONTHEANTERIORCERVICALREGION(ANTERIORTRIANGLE):• submandibular(digastric)triangle• submentaltriangle• caroRdtriangle• muscular(omotracheal)triangle
THENECK–THECERVICALREGIONS
THEANTERIORCERVICALREGIONTHESUBMANDIBULAR(DIGASTRIC)TRIANGLEMAINCONTENTS:• submandibularglandalmostfillstriangle• submandibularlymphnodes• hypoglossalnerve• mylohyoidnerve• partsoffacialarteryandvein
THESUBMENTALTRIANGLEMAINCONTENTS:• submentallymphnodesand• smallveinsthatunitetoformanteriorjugularvein
THENECK–THECERVICALREGIONS
THEANTERIORCERVICALREGIONTHECAROTIDTRIANGLEThecaroRdtriangleisavascularareaboundedby:• thesuperiorbellyoftheomohyoid,• theposteriorbellyofthedigastric,• theanteriorborderoftheSCM
TheneurovascularstructuresinthecaroRdtrianglearesurroundedbythecaroPdsheath:• thecaroPdarteriesmedially• theIJVlaterally• thevagusnerveposteriorly
THENECK–THECERVICALREGIONS
THEANTERIORCERVICALREGIONTHECAROTIDTRIANGLEMAINCONTENTS:• caroRdsheathcontainingcommoncaroRdarteryanditsbranches
TheneurovascularstructuresinthecaroRdtrianglearesurroundedbythecaroPdsheath:• thecaroPdarteriesmedially• theIJVlaterally• thevagusnerveposteriorly
THENECK–THECERVICALREGIONS
THEANTERIORCERVICALREGIONTHECAROTIDTRIANGLEMAINCONTENTS:• caroRdsheathcontainingcommoncaroRdarteryanditsbranches• internaljugularveinanditstributaries• vagusnerve• externalcaroRdarteryandsomeofitsbranches• hypoglossalnerveandsuperiorrootofansacervicalis• spinalaccessorynerve(CNXI)• thyroidgland,• larynx,andpharynx• deepcervicallymphnodes• branchesofcervicalplexus
THENECK–THECERVICALREGIONS
THEANTERIORCERVICALREGIONTHECAROTIDTRIANGLEThecaroRdtriangleisavascularareaboundedby:• thesuperiorbellyoftheomohyoid,• theposteriorbellyofthedigastric,• theanteriorborderoftheSCM
THEMUSCULAR(OMOTRACHEAL)TRIANGLEMAINCONTENTS:• sternothyroidandsternohyoidmuscles• thyroidandparathyroidglands
THECUTANEOUSANDSUPERFICIALMUSCLESOFNECKPlatysma-cervicalbranchoffacialnerve(CNVII)Sternocleidomastoid(SCM)-spinalaccessorynerve(CNXI,motor);C2andC3nerves(painandpropriocepRon)Trapezius-spinalaccessorynerve(CNXI;motor);C2andC3nerves(painandpropriocepRon)
THENECK–THEMUSCLESOFTHENECK
THEMUSCLESINLATERALCERVICALREGION• spleniuscapiRs• levatorscapulae• anteriorscalene• middlescalene• posteriorscalene
Thesuprahyoidregioncontains4muscles:• Mylohyoid-nervetomylohyoid,CNV3• Digastric-anteriorbellyCNV3;posteriorbellyCNVII• Stylohyoid-CNVII• Geniohyoid–C1viahypoglossalnerveCNXIITheinfrahyoidregioncontains4musclescommonlycalledstrapmuscles:• Omohyoid-C1–C3byabranchofansacervicalis• Sternohyoid-C1–C3byabranchofansacervicalis• Sternothyroid-C2andC3byabranchofansacervicalis• Thyrohyoid-C1viahypoglossalnerve(CNXII)
THENECK–THEMUSCLESOFTHENECK
THEMUSCLESINANTERIORCERVICALREGION
THENECK–THEARTERIESOFTHENECK
THELATERALCERVICALREGIONThearteriesinthelateralcervicalregioninclude:• thelateralbranchesofthethyrocervicaltrunk• thethirdpartofthesubclavianartery• partoftheoccipitalartery
Thethirdpartofthesubclavianarterysuppliesbloodtotheupperlimb.Itishiddenintheinferiorpartofthelateralcervicalregion,posterosuperiortothesubclavianvein.
Thethirdpartofthearteryisthelongestandmostsuperficialpart.Itliesonthe1strib,anditspulsaRonscanbefeltbyapplyingdeeppressureintheomoclaviculartriangle.
THENECK–THEARTERIESOFTHENECK
THEANTERIORCERVICALREGIONThecommoncaroPdarterydividesinto:• theinternalcaroRdartery• theexternalcaroRdartery
ThecaroPdsinus,aslightdilaRonoftheproximalpartoftheinternalcaroRdartery.Innervatedprincipallybytheglossopharyngealnerve(CNIX)throughthecaroRdsinusnerveaswellasbythevagusnerve(CNX),itisabaroreceptor(pressoreceptor)thatreactstochangesinarterialbloodpressure.
ThecaroPdbody:asmall,reddishbrownovoidmassofRssueinlifethatliesonthemedial(deep)sideofthebifurcaRonofthecommoncaroRdartery.SuppliedmainlybythecaroRdsinusnerve(CNIX)andbyCNX,itisachemoreceptorthatmonitorsthelevelofoxygenintheblood
• C3-C4JUNCTION• SUPERIORBORDEROF
THYROIDCARTILAGE
THENECK–THEARTERIESOFTHENECK
THEANTERIORCERVICALREGIONSuperiorly,thecommoncaroPdisreplaced
bytheinternalcaroPdartery.
TheinternalcaroPdarteryhasNOBRANCHESintheneck.TheexternalcaroRdhasseveral.
TherightcommoncaroPdarterybeginsatthebifurcaRonofthebrachiocephalictrunk.Therightsubclavianarteryistheotherbranchofthisbrachiocephalictrunk.
Fromthearchoftheaorta,theleccommoncaroPdarteryascendsintotheneck.
THENECK–THEARTERIESOFTHENECK
THEANTERIORCERVICALREGIONTheinternalcaroPdarteriesaredirectconRnuaRonsofthecommoncaroRdssuperiortotheoriginoftheexternalcaroRdartery,atthelevelofthesuperiorborderofthethyroidcarRlage.
C3-C4JUNCTIONlevelofupperborderofthyroidcarRlageandbifurcaRonofcommon
caroRdartery.
TheexternalcaroPdarteriessupplymoststructuresexternaltothecranium.TheorbitandthepartoftheforeheadandscalpsuppliedbythesupraorbitalarteryarethemajorexcepRons.
THENECK–THEARTERIESOFTHENECK
THEANTERIORCERVICALREGIONTheexternalcaroPdarteries-sixarteriesarisefromtheexternalcaroRdartery:• ascendingpharyngealartery• occipitalartery• posteriorauricularartery• superiorthyroidartery• lingualartery• facialartery• maxillaryartery(T)• superficialtemporala.(T)
Theinferiorthyroidisabranchof
thesubclavianartery.
THENECK–THEARTERIESOFTHENECK
THEANTERIORCERVICALREGIONTheascendingpharyngealarterysendsbranchestothepharynx,prevertebralmuscles,middleear,andcranialmeninges.
Theoccipitalarteryendsbydividingintonumerousbranchesintheposteriorpartofthescalp.Theposteriorauriculararterysuppliestheadjacentmuscles;paroRdgland;facialnerve;andstructuresinthetemporalbone,auricle,andscalp.Thesuperiorthyroidarterygivesoffbranchestothyroidgland,theinfrahyoidmusclesandtheSCMandgivesrisetothesuperiorlaryngealartery,supplyingthelarynx.
Thelingualarterydividesintothedeeplingualandsublingualarteries.
TheexternalcaroPdarteriesisdividingintotwoterminalbranches:• themaxillaryartery• thesuperficialtemporalartery
THENECK–THEARTERIESOFTHENECK
THEANTERIORCERVICALREGIONThesubclavianartery:• rightfromthebrachiocephalictrunk• lecfromtheaorRcarch
Thesubclavianarterysuppliesbloodtotheupperlimb.1. medialpart2. posteriorpart3. lateralpart
Thesubclavianartery–branches:1. thyrocervicaltrunk
a.inferiorthyroidb.ascendingcervicalc.suprascapular
2.costocervicaltrunk
THENECK–THEVEINSOFTHENECK
THELATERALCERVICALREGIONTheexternaljugularvein(EJV)beginsneartheangleofthemandiblebytheunionoftheposteriordivisionoftheretromandibularveinwiththeposteriorauricularvein.
Theexternaljugularvein(EJV)descendstotheinferiorpartofthelateralcervicalregionandterminatesinthesubclavianvein
Thesubclavianveinuniteswiththeinternaljugularvein(IJV)toformthebrachiocephalicvein.
MostveinsintheanteriorcervicalregionaretributariesoftheIJV,typicallythelargestveinintheneck.
TheIJVdrainsbloodfromthebrain,anteriorface,cervicalviscera,anddeepmusclesoftheneck.
THENECK–THEVEINSOFTHENECK
THEANTERIORCERVICALREGION
TheIJVcommencesatthejugularforamenintheposteriorcranialfossaasthedirectconRnuaRonofthesigmoidsinus
FromadilaRonatitsorigin,thesuperiorbulboftheIJV,theveindescendsinthecaroRdsheath
TheinferiorendoftheIJVdilatestoformtheinferiorbulboftheIJV.ThisbulbhasabicuspidvalvethatpermitsbloodtoflowtowardtheheartwhileprevenRngbackflowintothevein.
THENECK–THEVISCERAOFTHENECK
THETHYROIDGLANDDevelopmentofthethyroidglandbeginsintheflooroftheembryonicpharynxatthesiteindicatedbyasmallpit,theforamencecum,inthedorsumofthepostnataltongue.
Thedevelopingglandrelocatesfromthetongueintotheneck,passinganteriortothehyoidandthyroidcarRlagestoreachitsfinalposiRonanterolateraltothesuperiorpartofthetrachea.
DuringthisrelocaRon,thethyroidglandisa_achedtotheforamencecumbythethyroglossalduct.
THENECK–THEVISCERAOFTHENECK
THETHYROIDGLANDThethyroidglandliesdeeptothesternothyroidandsternohyoidmuscles,locatedanteriorlyintheneckattheleveloftheC5–T1vertebrae.Itconsistsprimarilyofrightandlellobes,anterolateraltothelarynxandtrachea.
Thethyroidglandissurroundedbyathinfibrouscapsule
ThehighlyvascularthyroidglandissuppliedbythesuperiorandinferiorthyroidarteriesUsuallythefirstbranchesoftheexternalcaroRdarteries,thesuperiorthyroidarteriesdivideintoanteriorandposteriorbranchessupplyingmainlytheanterosuperioraspectofthegland.
Theinferiorthyroidarteries,thelargestbranchesofthethyrocervicaltrunksarisingfromthesubclavianarteries.
THENECK–THEVISCERAOFTHENECK
THETHYROIDGLANDThelymphaRcvesselsofthethyroidglandrunintheinterlobularconnecRveRssue
ThevesselspassiniRallytoprelaryngeal,pretracheal,andparatracheallymphnodes.
NERVESOFTHYROIDGLANDThesefibersarevasomotor,notsecretomotor.TheycauseconstricRonofbloodvessels.EndocrinesecreRonfromthethyroidglandishormonallyregulatedbythepituitarygland.