the abdomen - imul.umlub.edu.plimul.umlub.edu.pl/en/system/files/1. abdominal cavity....

THEABDOMEN

•  ABDOMINALCAVITY

•  ANTEROLATERALANDPOSTERIORABDOMINALWALL

•  INGUINALCANAL

THEABDOMINALCAVITY

THEABDOMINALCAVITY:•formsthesuperiorandmajorpartoftheabdominopelviccavity,thatextendsbetweenthethoracicdiaphragmandpelvicdiaphragm•hasnofloorofitsownbecauseitisconOnuouswiththepelviccavity•extendssuperiorlyintotheosseocarOlaginousthoraciccagetothe4thintercostalspace•isthelocaOonofmostdigesDveorgans,partsoftheurogenitalsystem

THEABDOMINALCAVITY

NineregionsoftheabdominalcavityareusedtodescribethelocaOonofabdominalorgans,pains,orpathologies.

Theregionsaredelineatedbyfourplanes:•  twosagiGal(verOcal)•  twotransverse(horizontal)planes.

THEABDOMINALCAVITY

ThetwoSAGITTALPLANESareusuallythemidclavicularplanes:•  fromthemidpointoftheclavicles•  tothemidinguinalpoints-midpointsofthelinesjoiningthe

anteriorsuperioriliacspine(ASIS)andthepubictuberclesoneachside.

TheTRANSVERSEPLANESare:•  thesubcostalplane,passingthroughtheinferiorborderofthe

10thcostalcarOlageoneachside•  thetranstubercularplane,passingthroughtheiliactubercles

(approximately5cmposteriortotheASISoneachside)andthebodyoftheL5vertebra.

THEABDOMINALCAVITY

Thetranspyloricplane,extrapolatedmidwaybetween:•  thesuperiorbordersofthemanubriumofthesternumand•  thepubicsymphysis-typicallytheL1vertebrallevel,commonly

transectsthepylorus

TheinterspinousplanepassesthroughtheeasilypalpatedASISoneachside.

FormoregeneralclinicaldescripOons,fourquadrantsoftheabdominalcavityaredefinedby:•  thetransversetransumbilicalplane,passingthroughtheumbilicus

(L3-L4level)•  theverOcalmedianplane

THEABDOMINALCAVITY

THEABDOMEN

•  ABDOMINALCAVITY

•  ANTEROLATERALANDPOSTERIORABDOMINALWALL

•  INGUINALCANAL

THEANTEROLATERALABDOMINALWALL

Theboundariesoftheanterolateralabdominalwall:•  superiorlybythecarOlagesofthe7th–10thribsandthexiphoid

processofthesternum•  inferiorlybytheinguinalligamentandthesuperiormarginsofthe

anterolateralaspectsofthepelvicgirdle

Theanterolateralabdominalwallconsistsof:•  skin•  subcutaneousOssue(superficialfascia)composedmainly

offat,•  musclesandtheiraponeuroses,•  deepfascia,•  extraperitonealfat,•  parietalperitoneum

Thewallismusculo-aponeuroOc,exceptfortheposteriorwall,whichincludesthelumbarregionofthevertebralcolumn.

THEANTEROLATERALABDOMINALWALL

FasciaoftheAnterolateralAbdominalWallThesubcutaneousDssuehastwolayers:•  thesuperficialfabylayerCAMPERFASCIA•  thedeepmembranouslayerSCARPAFASCIAThemembranouslayerconOnuesinferiorlyintotheperinealregionasthesuperficialperinealfascia-COLLESFASCIASuperficial,intermediate,anddeeplayersofinvesOngfasciacovertheexternalaspectsofthethreemusclelayersoftheanterolateralabdominalwallandtheiraponeurosesTheinternalaspectoftheabdominalwallislinedwithmembranousandareolarsheetsofvaryingthicknessconsOtuOngendoabdominalfascia.

THEANTEROLATERALABDOMINALWALL

FasciaoftheAnterolateralAbdominalWallTheparietalperitoneumisinternaltothetransversalisfasciaandisseparatedfromitbyavariableamountofextraperitonealfat.TheparietalperitoneumisformedbyasinglelayerofepithelialcellsandsupporOngconnecOveOssue.

THEMUSCLESOFANTEROLATERALABDOMINALWALL

THEMUSCLESOFTHEABDOMINALWALL

Therearefive(bilaterallypaired)musclesintheanterolateralabdominalwall:threeflatmusclesandtwoverOcalmuscles.

Thethreeflatmusclesarethe:externaloblique,internaloblique,transversusabdominis.

AllthreeflatmusclesareconOnuedanteriorlyandmediallyasstrong,sheet-likeaponeuroses

Betweenthemidclavicularline(MCL)andthemidline,theaponeurosesformthetough,aponeuroOc,tendinousrectussheathenclosingtherectusabdominismuscle.

THEMUSCLESOFTHEABDOMINALWALL

Theaponeurosestheninterweavewiththeirfellowsoftheoppositeside,formingamidlineraphe-thelineaalbaThelineaalbaextendsfromthexiphoidprocesstothepubicsymphysis.

ThetwoverDcalmusclesoftheanterolateralabdominalwall,

containedwithintherectussheath,arethelargerectus

abdominisand

thesmallpyramidalis

THEMUSCLESOFTHEABDOMINALWALL

Themusclesofanteriorabdominalwall:•  EXTERNALOBLIQUEMUSCLE•  INTERNALOBLIQUEMUSCLE•  TRANSVERSUSABDOMINISMUSCLE•  RECTUSABDOMINISMUSCLE•  PYRAMIDALIS

THEMUSCLESOFTHEABDOMINALWALL

Theexternalobliquemuscleisthelargestandmostsuperficialofthethreeflatanterolateralabdominalmuscles.TheinferiormarginoftheexternalobliqueaponeurosisisthickenedandspansbetweentheASISandthepubictubercleastheinguinalligament.

Theintermediateofthethreeflatabdominalmuscles,theinternalobliqueisathinmuscularsheetthatfansoutanteromedially.

Thefibersofthetransversusabdominis,theinnermostofthethreeflatabdominalmuscles

THEMUSCLESOFTHEABDOMINALWALL

Betweentheinternalobliqueandthetransversusabdominismusclesisaneurovascularplane-containsthenervesandarteriessupplyingtheanterolateralabdominalwall.

TherectusabdominisistheprincipalverOcalmuscleoftheanteriorabdominalwall.It’sbroadsuperiorly,narrowinferiorly.Mostoftherectusabdominisisenclosedintherectussheath.

TherectusmuscleisanchoredtransverselybyabachmenttotheanteriorlayeroftherectussheathatthreeormoretendinousintersecDons.

THEMUSCLESOFTHEABDOMINALWALL

Thepyramidalisisasmall,insignificanttriangularmusclethatisabsentinapproximately20%ofpeople.

Therectussheathisthestrong,incompletefibrouscompartmentoftherectusabdominisandpyramidalismuscles

THENERVESOFTHEABDOMINALWALL

NERVESOFANTEROLATERALABDOMINALWALL:•  Thoraco-abdominalnerves•  Lateral(thoracic)cutaneousbranches•  Subcostalnerve•  Iliohypogastricandilio-inguinalnerves

thesenervescommunicatewitheachother

T10suppliestheskinaroundtheumbilicus

THEVESSELSOFTHEABDOMINALWALL

Theprimarybloodvessels(arteriesandveins):•  Superiorepigastricvesselsandbranchesofthemusculophrenic

vesselsfromtheinternalthoracicvessels.•  Inferiorepigastricanddeepcircumflexiliacvesselsfromthe

externaliliacvessels.

•  Superficialcircumflexiliacandsuperficialepigastricvesselsfromthefemoralarteryandgreatersaphenousvein,respecOvely.

•  Posteriorintercostalvesselsofthe11thintercostalspaceandtheanteriorbranchesofsubcostalvessels.

THEANTERIORABDOMINALWALL

LYMPHATICSINTHEREGIONABOVETHEUMBILICUS•  drainintotheaxillarylymphnodes.LYMPHATICSINTHEREGIONBELOWTHEUMBILICUS•  drainintothesuperficialinguinalnodes.SUPERFICIALINGUINALLYMPHNODES•  receivelymphfromthelowerabdominalwall,bubocks,penis,

scrotum,labiummajus,andthelowerpartsofthevaginaandanalcanal.Theirefferentvesselsprimarilyentertheexternaliliacnodesand,ulOmately,thelumbar(aorOc)nodes.

THEPOSTERIORABDOMINALWALL

POSTERIORABDOMINALWALL

THEPOSTERIORABDOMINALWALL

Theposteriorabdominalwall:•  Fivelumbarvertebrae•  Posteriorabdominalwallmuscles•  Diaphragm•  Fascia•  Lumbarplexus•  Fat,nerves,vessels(e.g.,aortaandIVC),andlymphnodes.

THEPOSTERIORABDOMINALWALL

Theposteriorabdominalwalliscoveredwiththelayerofendoabdominalfasciathatliesbetweentheparietalperitoneumandthemuscles.

Thethoracolumbarfasciaisanfascialcomplexabachedtothevertebralcolumnmediallyandhasposterior,middle,andanteriorlayerswithmusclesenclosedbetweenthem.

THEPOSTERIORABDOMINALWALL

Themusclesoftheposteriorabdominalwall:•  Psoasmajor:passinginferolaterally.

•  Iliacus:lyingalongthelateralsidesoftheinferiorpartofthepsoasmajor.

•  Quadratuslumborum:lyingadjacenttothetransverseprocessesofthelumbarvertebraeandlateraltosuperiorpartsofthepsoasmajor.

THEPOSTERIORABDOMINALWALL

PSOASMAJOR•  lieslateraltothelumbarvertebrae•  passesinferolaterally•  deeptotheinguinalligament•  lumbarplexusisembeddedintheposteriorpartofthepsoas

major

ILIACUS•  liesalongthelateralsideoftheinferiorpartofthepsoasmajor•  psoasminorandiliacusmusclesmergeinferiorly;collecOvelyform

iliopsoasmuscle

QUADRATUSLUMBORUM•  thequadrilateralquadratuslumborumformsathickmuscularsheet

THEPOSTERIORABDOMINALWALL

VESSELSOFPOSTERIORABDOMINALWALL

THEPOSTERIORABDOMINALWALL

ABDOMINALAORTA:•  beginsattheaorDchiatusinthediaphragmattheleveloftheT12

vertebra•  endsattheleveloftheL4vertebrabydividingintotherightand

le\commoniliacarteriesItdescendsanteriortothebodiesoftheT12–L4vertebrae

Thecommoniliacarteriesdivergeandruninferolaterally,followingthemedialborderofthepsoasmusclestothepelvicbrim-divideintotheinternalandexternaliliacarteries.

•  Theinternaliliacarteryentersthepelvis.•  Theexternaliliacarteryfollowstheiliopsoasmuscle,givesriseto

theinferiorepigastricanddeepcircumflexiliacarteries

THEPOSTERIORABDOMINALWALL

RELATIONSOFABDOMINALAORTA:•Celiacplexusandganglion•Bodyofthepancreasandsplenicvein•Lejrenalvein•Horizontalpartoftheduodenum•CoilsofsmallintesOne

RELATIONSOFABDOMINALAORTA:Ontheright,theaortaisrelatedtotheazygosvein,cisternachyi,thoracicduct,rightcrusofthediaphragm,andrightceliacganglion.Onthele\,theaortaisrelatedtothelejcrusofthediaphragmandthelejceliacganglion.

THEPOSTERIORABDOMINALWALL

BRANCHESOFTHEABDOMINALAORTA

THEPOSTERIORABDOMINALWALL

VEINSOFPOSTERIORABDOMINALWALLTheveinsoftheposteriorabdominalwallaretributariesoftheIVC,exceptforthele\tesDcularorovarianvein,whichentersthelejrenalveininsteadofenteringtheIVC

TheIVCreturnsbloodfromthe:•  lowerlimbs,•  mostoftheback,•  abdominalwalls,•  abdominopelvicviscera.

THEPOSTERIORABDOMINALWALL

BloodfromtheabdominalviscerapassesthroughtheportalvenoussystemandtheliverbeforeenteringtheIVCviathehepaDcveins.

Theinferiorvenacava(IVC)beginsanteriortotheL5vertebrabytheunionofthecommoniliacveins.

TheIVCleavestheabdomenbypassingthroughthecavalopeninginthediaphragmandentersthethoraxattheT8

vertebrallevel.

THEPOSTERIORABDOMINALWALL

TheIVCcollectsbloodfromthelowerlimbsandnon-portalbloodfromtheabdomenandpelvis.ThetributariesoftheIVCcorrespondtothepairedvisceralandparietalbranchesoftheabdominalaorta.

AllthebloodfromthegastrointesDnaltractiscollectedbythehepaOcportalsystemandpassesthroughthehepaOcveinstotheIVC.TheveinsthatcorrespondtotheunpairedvisceralbranchesoftheaortaareinsteadtributariesofthehepaAcportalvein.

THEPOSTERIORABDOMINALWALL

Thebranchescorrespondingtothepairedvisceralbranchesoftheabdominalaortaincludethe:•  rightsuprarenalvein,•  rightandlejrenalveins,•  rightgonadal(tesOcularorovarian)vein.TheleBsuprarenalandgonadalveinsdrainindirectlyintotheIVCbecausetheyaretributariesoftheleBrenalvein.

THEPOSTERIORABDOMINALWALL

LYMPHATICVESSELSLymphaOcvesselsandlymphnodesliealongtheaorta,IVC,andiliacvessels.

CISTERNACHYLIIsthelowerdilatedendofthethoracicductandliesjusttotherightandposteriortotheaorta,usuallybetweentwocruraofthediaphragm.IsformedbytheintesOnalandlumbarlymphtrunks.

ThethoracicductascendsthroughtheaorOchiatusinthediaphragmintotheposteriormediasOnum,whereitcollectsmoreparietalandvisceraldrainage,parOcularlyfromthelejupperquadrantofthebody.

THEPOSTERIORABDOMINALWALL

LYMPHNODESRELATEDTOTHEAORTA1.PreaorDcNodesIncludetheceliac,superiormesenteric,andinferiormesentericnodes;drainthelymphfromtheGItract,spleen,pancreas,gallbladder,andliver;andtheirefferentvesselsformtheintesOnaltrunk.2.ParaaorDc,Lumbar,orLateralAorDcLymphNodesDrainlymphfromthekidneys,suprarenalglands,testesorovaries,uterus,anduterinetubes;receivelymphfromthecommon,internal,orexternaliliac;andtheirefferentvesselsformtherightandlejlumbartrunks.

THEABDOMEN

•  ABDOMINALCAVITY

•  ANTEROLATERALANDPOSTERIORABDOMINALWALL

•  INGUINALCANAL

THEINGUINALREGION

INGUINALREGIONTheinguinalregion(groin)extendsbetweentheASISandpubictubercle.Itisimportant:•  structuresexitandentertheabdominalcavity•  pathwaysofexitandentrancearepotenOalsitesofherniaOon

INGUINAL(HESSELBACH’S)TRIANGLEIsboundedmediallybythelineasemilunaris(lateraledgeoftherectusabdominis),laterallybytheinferiorepigastricvessels,andinteriorlybytheinguinalligament.

INGUINAL(HESSELBACH’S)TRIANGLEIsanareaofpotenOalweaknessandhenceisacommonsiteofadirectinguinalhernia.

THEINGUINALREGION

INGUINALREGIONTheinguinalligamentisadensebandconsOtuOngtheinferiormostpartoftheexternalobliqueaponeurosis.Theiliopubictractisthethickenedinferiormarginofthetransversalisfascia,whichappearsasafibrousbandrunningparallelandposterior(deep)totheinguinalligament.TheinguinalligamentandiliopubictractspananareaofinnateweaknessinthebodywallintheinguinalregioncalledthemyopecDnealorifice

THEINGUINALREGION

INGUINALCANALTheinguinalcanalisformedinrelaOontotherelocaOonofthetesOsduringfetaldevelopment.Itliesparallelandsuperiortothemedialhalfoftheinguinalligament-approximately4cmlong.ThemainoccupantoftheinguinalcanalisthespermaDccordinmalesandtheroundligamentoftheuterusinfemales.TheinguinalcanalalsocontainsbloodandlymphaOcvesselsandtheilio-inguinalnerveinbothsexes.

THEINGUINALREGION

Theinguinalcanalhasanopeningateachend:•  thedeep(internal)inguinalringistheentrancetotheinguinal

canal.Itislocatedsuperiortothemiddleoftheinguinalligamentandlateraltotheinferiorepigastricartery

•  thesuperficial(external)inguinalringistheexitbywhichthespermaOccordinmales,ortheroundligamentinfemales,emergesfromtheinguinalcanal

Thelateralcrusabachestothepubictubercle,andthemedialcrusabachestothepubiccrest.

THEINGUINALREGION

Theinguinalcanalhastwowalls(anteriorandposterior),aroof,andafloor.

ANTERIORWALL:formedbytheexternalobliqueaponeurosisthroughoutthelengthofthecanal;itslateralpartisreinforcedbymusclefibersoftheinternaloblique.

POSTERIORWALL:formedbythetransversalisfascia.Itsmedialpartisreinforcedbypubicabachmentsoftheinternalobliqueandtransversusabdominisaponeuroses-inguinalfalx.

THEINGUINALREGION

ROOF:formedlaterallybythetransversalisfascia,centrallybymusculo-aponeuroOcarchesoftheinternalobliqueandtransversusabdominis,andmediallybythemedialcrusoftheexternalobliqueaponeurosis.

FLOOR:formedlaterallybytheiliopubictract,centrallybyguberformedbytheinfoldedinguinalligament,andmediallybythelacunarligament.

THEINGUINALREGION

1.Anteriorwall:aponeurosesoftheexternalobliqueandinternalobliquemuscles.2.Posteriorwall:aponeurosisofthetransverseabdominalmuscleandtransversalisfascia.3.Superiorwall(roof):archingfibersoftheinternalobliqueandtransversemuscles.4.Inferiorwall(floor):inguinalandlacunarligaments.

THEINGUINALREGION

Mostgroinhernias:•  inmalespasssuperiortotheiliopubictract(inguinalhernias),•  whereasmostpassinferiortoitinfemales(femoralhernias).

Aninguinalherniaisaprotrusionofparietalperitoneumandviscera,suchasthesmallintesOne,throughanormalorabnormalopeningfromthecavityinwhichtheybelong.

Themajorityofabdominalherniasoccurintheinguinalregion.Inguinalherniasaccountfor75%ofabdominalhernias.

THEINGUINALREGION

Thetwotypesofinguinalherniaaredirectandindirectinguinalhernias.Morethantwothirdsareindirecthernias.Indirectinguinalherniasdevelopattheinternalinguinalringandarelateraltotheinferiorepigastricartery.