the thorax - imulimul.pl/system/files/thorax - bones joints muscles.pdfthe ribs ribs are curved,...

THORACICWALLBREAST

THETHORAX

THETHORAX

•  THORACICWALL

•  BREAST

THETHORAX

THORACICWALL

THETHORAX

Thepartofthebodybetweentheneckandabdomen.Thethoraciccage(ribcage),withthehorizontalbarsformedbyribsandcostalcar;lages,isalsosupportedbythever>calsternum(breastbone)andthoracicvertebrae

THETHORAX-BONES&JOINTS

Thethoracicskeletonincludes:•  12pairsofribsandassociatedcostalcar>lages,•  12thoracicvertebraeandtheintervertebral(IV)discsinterposed

betweenthem,•  andthesternum.

THERIBS

Ribsarecurved,flatbonesthatformmostofthethoraciccage


Therearethreetypesofribsthatcanbeclassifiedastypicaloratypical:•  true(vertebrosternal)ribs(1st–7thribs)•  false(vertebrochondral)ribs(8th,9th,andusually10thribs)•  floa;ng(vertebral,free)ribs(11th,12th,andsome>mes10thribs)

THERIBS

Therearethreetypesofribsthatcanbeclassifiedastypicaloratypical:•  true(vertebrosternal)ribs(1st–7thribs):theyaWachdirectlytothesternumthroughtheirowncostalcar>lages.•  false(vertebrochondral)ribs(8th,9th,andusually10thribs):theircar>lagesareconnectedtothecar>lageoftheribabovethem;thustheirconnec>onwiththesternumisindirect.•  floa;ng(vertebral,free)ribs(11th,12th,andsome;mes10thribs):therudimentarycar>lagesoftheseribsdonotconnectevenindirectlywiththesternum;insteadtheyendintheposteriorabdominalmusculature.


THERIBS THETHORAX-BONES&JOINTS

Typicalribs(3rd–9th)havethefollowingcomponents:•Head:hastwofacets,oneforar>cula>onwiththenumericallycorrespondingvertebraandonefacetforthevertebrasuperiortoit.•Neck:connectstheheadoftheribwiththebodyatthelevelofthetubercle.•Tubercle:ar>culateswiththecorrespondingtransverseprocessofthevertebra,•Body(sha[):thin,flat,andcurved.

Typicalribs(3rd–9th)havethefollowingcomponents:•Head•Neck•Tubercle•Body


ATYPICALRIBS(1st,2nd,and10th–12th)aredissimilar:•  the1stribisthebroadest(i.e.,itsbodyiswidestandnearly

horizontal),shortest,andmostsharplycurved

•  the1stribhasasinglefacetonitsheadforar>cula>onwiththeT1vertebraonly

•  the1stribhastwotransverselydirectedgroovescrossingitssuperiorsurfaceforthesubclavianvessels

•  the1stribhasthegroovesseparatedbyascalenetubercleandridge,towhichtheanteriorscalenemuscleisaWached.


Atypicalribs(1st,2nd,and10th–12th)aredissimilar:•  the2ndribishasathinner,lesscurvedbody•  hastwofacetsforar>cula>onwiththebodiesoftheT1andT2

vertebrae

Atypicalribs(1st,2nd,and10th–12th)aredissimilar:•  The10th–12thribs,likethe1strib,haveonlyonefacetontheirheadsandar;culatewithasinglevertebra.

Atypicalribs(1st,2nd,and10th–12th)aredissimilar:•The11thand12thribsareshortandhavenoneckortubercle.

THECOSTALCARTILAGES THETHORAX-BONES&JOINTS

Costalcar;lagesprolongtheribsanteriorlyandcontributetotheelas>cityofthethoracicwall,providingaflexibleaWachmentfortheiranteriorends(>ps).

Intercostalspacesseparatetheribsandtheircostalcar>lagesfromoneanother

THETHORACICVERTEBRAE THETHORAX-BONES&JOINTS

Characteris>cfeaturesofthoracicvertebraeinclude:•  Bilateralcostalfacets(demifacets)onthevertebralbodies,usually

occurringininferiorandsuperiorpairs,forar>cula>onwiththeheadsofribs.

•  Costalfacetsonthetransverseprocessesforar>cula>onwiththetuberclesofribs,exceptfortheinferiortwoorthreethoracicvertebrae.

•  Long,inferiorlyslan>ngspinousprocesses.

THETHORACICVERTEBRAE THETHORAX-BONES&JOINTS

Superiorandinferiorcostalfacetsoccurasbilaterallypaired,planarsurfacesonthesuperiorandinferiorposterolateralmarginsofthebodiesoftypicalthoracicvertebrae(T2–T9).

Atypicalthoracicvertebrae:•  ThesuperiorcostalfacetsofvertebraT1arenotdemifacetsbecause

therearenodemifacetsontheC7vertebraabove,andrib1ar;culatesonlywithvertebraT1.T1hasatypicalinferiorcostalfacet.

•  T10hasonlyonebilateralpairof(whole)costalfacets,locatedpartlyonitsbodyandpartlyonitspedicle.

•  T11andT12alsohaveonlyasinglepairof(whole)costalfacets,locatedontheirpedicles.

THESTERNUM THETHORAX-BONES&JOINTS

Thesternumistheflat,elongatedbonethatformsthemiddleoftheanteriorpartofthethoraciccage.

Thesternumconsistsofthreeparts:•  manubrium,•  body,and•  xiphoidprocess


Theeasilypalpatedconcavecenterofthesuperiorborderofthemanubriumisthejugularnotch(suprasternalnotch).

ThejugularnotchliesattheleveloftheinferiorborderofthebodyofT2vertebraandthespacebetweenthe1stand2ndthoracicspinousprocesses.

Themanubriumandbodyofthesternumlieinslightlydifferentplanessuperiorandinferiortotheirjunc>on,

themanubriosternaljoint;hence,theirjunc>onformsaprojec>ngsternalangle(ofLouis).

Inferolateraltotheclavicularnotch,thecostalcar>lageofthe1stribis>ghtlyaWachedtothelateralborderofthemanubrium–

-thesynchondrosisofthefirstrib


Thebodyofthesternum,islonger,narrower,andthinnerthanthemanubrium,andislocatedattheleveloftheT5–T9vertebrae

Thexiphoidprocess,thesmallestandmostvariablepartofthesternum,isthinandelongated.ItsinferiorendliesatthelevelofT10vertebra.


Thexiphisternaljointisamidlinemarkerforthesuperiorlimitoftheliver,thecentraltendonofthediaphragm,andtheinferiorborderoftheheart.

JOINTSOFTHORACICWALL THETHORAX-BONES&JOINTS

•  Intervertebral(ofvertebraeT1–T12)•  Costovertebral(jointsofheadofrib)•  Costochondral•  Interchondral•  Sternocostal•  Sternoclavicular•  Manubriosternal

•  Xiphisternal

JOINTSOFTHORACICWALL THETHORAX-BONES&JOINTS


THETHORACICAPERTURES


Whilethethoraciccageprovidesacompletewallperipherally,itisopensuperiorlyandinferiorly.


Themuchsmallersuperioropening(aperture)isapassagewaythatallowscommunica>onwiththeneckandupperlimbs.

Thelargerinferioropeningprovidesthering-likeoriginofthediaphragm,whichcompletelyoccludestheopening.


TheSUPERIORTHORACICAPERTUREisbounded:•Posteriorly,byvertebraT1,thebodyofwhichprotrudesanteriorlyintotheopening.•Laterally,bythe1stpairofribsandtheircostalcar>lages.•Anteriorly,bythesuperiorborderofthemanubrium.


THETHORACICINLETSpace-occupyingtumoursinthisloca>onmaycompressadjacentstructures,leadingtotheclinicalcondi>oncalledthoracicoutletsyndrome.

THETHORAX-BONES&JOINTSTHETHORACICAPERTURES

Inferiorlythecavityofthethoraxisseparatedfromtheabdominalcontentsbyafibromuscularsheetcalledthediaphragm.


Thefloorofthethoraciccavity(thoracicdiaphragm)isdeeplyinvaginatedinferiorly(i.e.,ispushedupward)byvisceraoftheabdominalcavity.

TheINFERIORTHORACICAPERTUREisboundedasfollows:•Posteriorly,bythe12ththoracicvertebra,thebodyofwhichprotrudesanteriorlyintotheopening.•Posterolaterally,bythe11thand12thpairsofribs.•Anterolaterally,bythejoinedcostalcar>lagesofribs7–10,formingthecostalmargins.•Anteriorly,bythexiphisternaljoint.


THEMUSCLESOFTHETHORAX

MUSCLESOFTHORACICWALL


MUSCLESOFTHEPECTORALREGION:•  Pectoralismajor•  Subclavius•  Pectoralisminor

THETHORAX

•  Lateralandmedialpectoralnerves

•  Medialpectoralnerve

•  Nervetosubclavius

Thepectoralismajormuscleisthelargestandmostsuperficialofthepectoralregionmuscles.

Thesubclaviusandpectoralisminormusclesunderliepectoralismajor:•  subclaviusissmallandpasseslaterallyfromtheanteriorand

medialpartofribItotheinferiorsurfaceoftheclavicle;•  pectoralisminorpassesfromtheanteriorsurfacesofribsIIItoVto

thecoracoidprocessofthescapula.


Themusclesofthepectoralregionformtheanteriorwalloftheaxilla,aregionbetweentheupperlimbandtheneckthroughwhichallmajorstructurespass.

THETHORAX

Nerves,vessels,andlympha>csthatpassbetweenthepectoralregionandtheaxillapassthroughtheclavipectoralfasciabetweensubclaviusandpectoralisminororpassundertheinferiormarginsofpectoralismajorandminor.


Thetruemusclesofthethoracicwallarethe:serratusposterior,levatorescostarum,intercostal,subcostal,andtransversusthoracis.

THEMUSCLES


Thelevatorescostarummusclesare12fan-shapedmusclesthatelevatetheribs,buttheirrole,ifany,innormalinspira>onisuncertain.

THEMUSCLES

Theintercostalmusclesoccupytheintercostalspaces

Thesuperficiallayer-theexternalintercostals,theinnerlayer-theinternalintercostals.Thedeepestfibers-theinnermostintercostals.

Theexternalintercostalmuscles(11pairs)occupytheintercostalspacesfromthetuberclesoftheribsposteriorlytothecostochondraljunc>onsanteriorly.


Theexternalintercostalmusclesarecon>nuousinferiorlywiththeexternalobliquemusclesintheanterolateralabdominalwall.

THEMUSCLES

Theinternalintercostalmuscles(11pairs)rundeeptoandatrightanglestotheexternalintercostals.

Betweentheribsposteriorly,medialtotheangles,theinternalintercostalsarereplacedbytheinternalintercostalmembranes.

Theinferiorinternalintercostalmusclesarecon>nuouswiththeinternalobliquemusclesintheanterolateralabdominalwall.

Theinnermostintercostalmusclesaresimilartotheinternalintercostalsandareessen>allytheirdeeperparts.

Theinnermostintercostalsareseparatedfromtheinternalintercostalsbyintercostalnervesandvessels


Thesubcostalmusclesarevariableinsizeandshape,usuallybeingwelldevelopedonlyinthelowerthoracicwall.

THEMUSCLES

Thetransversusthoracismusclesconsistoffourorfiveslipsthatradiatesuperolaterallyfromtheposterioraspectoftheinferiorsternum.

Theexternalandinternalintercostalsareac>veduringinspira;onandexpira;on.Theroleofthesemusclesinproducingmovementoftheribsappearstoberelatedmainlytoforcedrespira;on.

Theprimaryroleoftheintercostalmusclesinrespira>onistosupport(increasethetonusorrigidityof)theintercostalspace.

Thediaphragmistheprimarymuscleofinspira>on.

NERVESOFTHETHORACICWALL

The12pairsofthoracicspinal

nervessupplythethoracicwall.

THERESPIRATORYSYSTEM

AssoonastheyleavetheIVforaminainwhichtheyareformed,themixedthoracicspinalnervesdivideinto

anteriorandposterior(primary)ramiorbranches

TheanteriorramiofnervesT1–T11formtheintercostalnerves

thatrunalongtheextentoftheintercostalspaces.


Neartheanglesoftheribs,thenervespassbetweentheinternalintercostalandtheinnermostintercostalmuscles.Atthispoint,theintercostalnervespasstoandthencon>nuetocourseinorjustinferiortothecostalgrooves,runninginferiortotheintercostalarteries.



Thebranchesofatypicalintercostalnerveare:•  Ramicommunicantes,orcommunica>ngbranches,thatconnect

eachintercostalnervetotheipsilateralsympathe>ctrunk.•  Collateralbranchesthatariseneartheanglesoftheribs•  LateralcutaneousbranchesthatariseneartheMAL•  Anteriorcutaneousbranchespiercethemusclesandmembranes

oftheintercostalspace•  Muscularbranchesthatsupplytheintercostal,subcostal,

transversusthoracis,levatorescostarum,andserratusposteriormuscles


ARTERIESOFTHORACICWALL

Thearterialsupplytothethoracicwallderivesfromthe:•  Thoracicaorta,throughtheposteriorintercostalandsubcostal

arteries.

•  Subclavianartery,throughtheinternalthoracicandsupremeintercostalarteries.

•  Axillaryartery,throughthesuperiorandlateralthoracicarteries.


Theintercostalarteriescoursethroughthethoracicwallbetweentheribs.

Eachintercostalspaceissuppliedbythreearteries:alargeposteriorintercostalartery(anditscollateralbranch)anda

smallpairofanteriorintercostalarteries.

VEINSOFTHORACICWALL THERESPIRATORYSYSTEMVEINSOFTHORACICWALL

Thereare11posteriorintercostalveinsandonesubcostalveinoneachside.Theposteriorintercostalveinsanastomosewiththeanteriorintercostalveins(tributariesofinternalthoracicveins).Mostposteriorintercostalveins(4–11)endintheazygos/hemi-azygosvenoussystem,whichconveysvenousbloodtothesuperiorvenacava(SVC).Theposteriorintercostalveinsofthe1stintercostalspaceusuallyenterdirectlyintotherightandle[brachiocephalicveins.

THEBREASTS


BREASTSThebreastsconsistofglandularandsuppor>ngfibrous;ssueembeddedwithinafaWymatrix,togetherwithbloodvessels,lympha>cs,andnerves.

THEBREASTS

Themammaryglandsareinthesubcutaneous>ssueoverlyingthepectoralismajorandminormuscles.

Atthegreatestprominenceofthebreastisthenipple,surroundedbyacircularpigmentedareaofskin,theareola

Theroughlycircularbodyofthefemalebreastrestsonabedofthebreastthatextendstransverselyfromthelateralborderofthesternumtothemidaxillarylineandver>callyfromthe2ndthrough6thribs.

FEMALEBREASTSTwothirdsofthebedareformedbythepectoralfasciaoverlyingthepectoralismajor;theotherthird,bythefasciacoveringtheserratusanterior.

THEBREASTS

Betweenthebreastandthepectoralfasciaisaloosesubcutaneous>ssueplaneorpoten>alspace–-theretromammaryspace.

Asmallpartofthemammaryglandmayextendalongtheinferolateraledgeofthepectoralismajortowardtheaxillaryfossa

(armpit),forminganaxillaryprocessortail(ofSpence).

ThemammaryglandsarefirmlyaWachedtothedermisoftheoverlyingskin,especiallybysubstan>alskinligaments,

thesuspensoryligamentsofCooper.

FEMALEBREASTSThesecondensa>onsoffibrousconnec>ve>ssue,par>cularlywelldevelopedinthesuperiorpartofthegland,helpsupportthelobesandlobulesofthemammarygland.

THEBREASTS

Thelac;ferousductsgiverisetobudsthatdevelopinto15–20lobulesofthemammarygland,whichcons>tutetheparenchyma(func>onalsubstance)ofthemammarygland.

Thuseachlobuleisdrainedbyalac;ferousduct.

Eachducthasadilatedpor>ondeeptotheareola,thelac;feroussinus,inwhichasmalldropletofmilkaccumulates

orremainsinthenursingmother.

Theareolaecontainnumeroussebaceousglands,whichenlargeduringpregnancyandsecreteanoilysubstance

FEMALEBREASTSThenipplesareconicalorcylindricalprominencesinthecentersoftheareolae.

THEBREASTS

Themammaryglandsaremodifiedsweatglands;therefore,theyhavenocapsuleorsheath.

Inmostwomen,thebreastsenlargeslightlyduringthemenstrualperiodfromincreasedreleaseofgonadotropichormones:follicle-s;mula;nghormone(FSH)andluteinizinghormone(LH)-ontheglandular>ssue.

VASCULATUREOFBREASTSThearterialsupplyofthebreastderivesfromthe:•  Medialmammarybranchesofperfora>ngbranchesandanterior

intercostalbranchesoftheinternalthoracicartery,origina>ngfromthesubclavianartery.

•  Lateralthoracicandthoraco-acromialarteries,branchesoftheaxillaryartery.

•  Posteriorintercostalarteries,branchesofthethoracicaortainthe2nd,3rd,and4thintercostalspaces.

THEBREASTS

Thevenousdrainageofthebreastismainlytotheaxillaryvein,butthereissomedrainagetotheinternalthoracicvein.

VASCULATUREOFBREASTS THEBREASTS

Thelympha;cdrainageofthebreastisimportantbecauseofitsroleinthemetastasisofcancercells.

Lymphpassesfromthenipple,areola,andlobulesoftheglandtothesubareolarlympha;cplexus.

VASCULATUREOFBREASTSFromthesubareolarlympha;cplexus:•  mostlymph(>75%),especiallyfromthelateralbreastquadrants,

drainstotheaxillarylymphnodes,ini>allytotheanteriororpectoralnodesforthemostpart.

•  mostoftheremaininglymph,par>cularlyfromthemedialbreastquadrants,drainstotheparasternallymphnodesortotheoppositebreast.

•  lymphfromtheinferiorquadrantsmaypassdeeplytoabdominal

lymphnodes(subdiaphragma>cinferiorphreniclymphnodes).

THEBREASTS

VASCULATUREOFBREASTSLymphfromtheaxillarynodesdrainsintoclavicular(infraclavicularandsupraclavicular)lymphnodesandfromthemintothesubclavianlympha;ctrunk,whichalsodrainslymphfromtheupperlimb.

THEBREASTS

Lymphfromtheparasternalnodesentersthebronchomedias>nallympha>ctrunks,whichalsodrainlymphfromthethoracicviscera.Thetermina>onofthelympha>ctrunksvaries.

Thesetrunksaredescribedasmergingwitheachotherandwiththejugularlympha;ctrunk,drainingtheheadandnecktoformashortrightlympha;cductontherightsideorenteringthetermina>onatthethoracicductonthele[side.

VASCULATUREOFBREASTS

Thetrunksopenindependentlyintothejunc>onoftheinternaljugularandsubclavianveins,therightorledvenousangles,thatformtherightandle[brachiocephalicveins.

THEBREASTS

NERVESOFBREASTSThenervesofthebreastderivefromanteriorandlateralcutaneousbranchesofthe4th-6thintercostalnerves.

THEBREASTS

Thebranchesoftheintercostalnervesconvey:•  sensoryfibersfromtheskinofthebreast•  sympathe;cfiberstothebloodvesselsinthebreastsandsmooth

muscleintheoverlyingskinandnipple.

the thorax - imulimul.pl/system/files/thorax - bones joints muscles.pdfthe ribs ribs are curved,...

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