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.