Download abdominal cavity

THEABDOMEN
•  ABDOMINALCAVITY
•  ANTEROLATERALANDPOSTERIORABDOMINALWALL
•  INGUINALCANAL
THEABDOMINALCAVITY
THEABDOMINALCAVITY:
•formsthesuperiorandmajorpartoftheabdominopelvic
cavity,thatextendsbetweenthethoracicdiaphragmandpelvic
diaphragm
•hasnofloorofitsownbecauseitisconOnuouswiththepelvic
cavity
•extendssuperiorlyintotheosseocarOlaginousthoraciccagetothe
4thintercostalspace
•isthelocaOonofmostdigesDveorgans,partsoftheurogenital
system
THEABDOMINALCAVITY
Nineregionsoftheabdominalcavityareusedtodescribethe
locaOonofabdominalorgans,pains,orpathologies.
Theregionsaredelineatedbyfourplanes:
•  twosagiGal(verOcal)
•  twotransverse(horizontal)planes.
THEABDOMINALCAVITY
ThetwoSAGITTALPLANESareusuallythemidclavicularplanes:
•  fromthemidpointoftheclavicles
•  tothemidinguinalpoints-midpointsofthelinesjoiningthe
anteriorsuperioriliacspine(ASIS)andthepubictuberclesoneach
side.
TheTRANSVERSEPLANESare:
•  thesubcostalplane,passingthroughtheinferiorborderofthe
10thcostalcarOlageoneachside
•  thetranstubercularplane,passingthroughtheiliactubercles
(approximately5cmposteriortotheASISoneachside)andthe
bodyoftheL5vertebra.
THEABDOMINALCAVITY
Thetranspyloricplane,extrapolatedmidwaybetween:
•  thesuperiorbordersofthemanubriumofthesternumand
•  thepubicsymphysis-typicallytheL1vertebrallevel,commonly
transectsthepylorus
TheinterspinousplanepassesthroughtheeasilypalpatedASISon
eachside.
FormoregeneralclinicaldescripOons,fourquadrantsofthe
abdominalcavityaredefinedby:
•  thetransversetransumbilicalplane,passingthroughtheumbilicus
(L3-L4level)
•  theverOcalmedianplane
THEABDOMINALCAVITY
THEABDOMEN
•  ABDOMINALCAVITY
•  ANTEROLATERALANDPOSTERIORABDOMINALWALL
•  INGUINALCANAL
THEANTEROLATERALABDOMINALWALL
Thewallismusculo-aponeuroOc,exceptfortheposteriorwall,which
includesthelumbarregionofthevertebralcolumn.
Theboundariesoftheanterolateralabdominalwall:
•  superiorlybythecarOlagesofthe7th–10thribsandthexiphoid
processofthesternum
•  inferiorlybytheinguinalligamentandthesuperiormarginsofthe
anterolateralaspectsofthepelvicgirdle
Theanterolateralabdominalwallconsistsof:
•  skin
•  subcutaneousOssue(superficialfascia)composedmainly
offat,
•  musclesandtheiraponeuroses,
•  deepfascia,
•  extraperitonealfat,
•  parietalperitoneum
THEANTEROLATERALABDOMINALWALL
FasciaoftheAnterolateralAbdominalWall
ThesubcutaneousDssuehastwolayers:
•  thesuperficialfabylayerCAMPERFASCIA
•  thedeepmembranouslayerSCARPAFASCIA
ThemembranouslayerconOnuesinferiorlyintotheperinealregionas
thesuperficialperinealfascia-COLLESFASCIA
Superficial,intermediate,anddeeplayersofinvesOngfascia
covertheexternalaspectsofthethreemusclelayersofthe
anterolateralabdominalwallandtheiraponeuroses
Theinternalaspectoftheabdominalwallislinedwithmembranous
andareolarsheetsofvaryingthicknessconsOtuOngendoabdominal
fascia.
THEANTEROLATERALABDOMINALWALL
FasciaoftheAnterolateralAbdominalWall
Theparietalperitoneumisinternaltothetransversalisfasciaandis
separatedfromitbyavariableamountofextraperitonealfat.
Theparietalperitoneumisformedbyasinglelayerofepithelialcells
andsupporOngconnecOveOssue.
THEMUSCLES
OFANTEROLATERALABDOMINALWALL
THEMUSCLESOFTHEABDOMINALWALL
Therearefive(bilaterallypaired)musclesintheanterolateral
abdominalwall:threeflatmusclesandtwoverOcalmuscles.
Thethreeflatmusclesarethe:
externaloblique,internaloblique,transversusabdominis.
AllthreeflatmusclesareconOnuedanteriorlyandmediallyasstrong,
sheet-likeaponeuroses
Betweenthemidclavicularline(MCL)andthemidline,the
aponeurosesformthetough,aponeuroOc,tendinousrectussheath
enclosingtherectusabdominismuscle.
THEMUSCLESOFTHEABDOMINALWALL
Theaponeurosestheninterweavewiththeirfellowsoftheopposite
side,formingamidlineraphe-thelineaalba
Thelineaalbaextendsfromthexiphoidprocesstothepubic
symphysis.
ThetwoverDcalmuscles
oftheanterolateral
abdominalwall,
containedwithinthe
rectussheath,are
thelargerectus
abdominis
and
thesmallpyramidalis
THEMUSCLESOFTHEABDOMINALWALL
Themusclesofanteriorabdominalwall:
•  EXTERNALOBLIQUEMUSCLE
•  INTERNALOBLIQUEMUSCLE
•  TRANSVERSUSABDOMINISMUSCLE
•  RECTUSABDOMINISMUSCLE
•  PYRAMIDALIS
THEMUSCLESOFTHEABDOMINALWALL
Theexternalobliquemuscleisthelargestandmost
superficialofthethreeflatanterolateralabdominalmuscles.
Theinferiormarginoftheexternalobliqueaponeurosisisthickened
andspansbetweentheASISandthepubictubercle
astheinguinalligament.
Theintermediateofthethreeflatabdominalmuscles,theinternal
obliqueisathinmuscularsheetthatfansoutanteromedially.
Thefibersofthetransversusabdominis,theinnermostofthethree
flatabdominalmuscles
THEMUSCLESOFTHEABDOMINALWALL
Betweentheinternalobliqueandthetransversusabdominis
musclesisaneurovascularplane-containsthenervesandarteries
supplyingtheanterolateralabdominalwall.
TherectusabdominisistheprincipalverOcalmuscleofthe
anteriorabdominalwall.It’sbroadsuperiorly,narrowinferiorly.
Mostoftherectusabdominisisenclosedintherectussheath.
Therectusmuscleisanchoredtransverselybyabachment
totheanteriorlayeroftherectussheathatthreeormore
tendinousintersecDons.
THEMUSCLESOFTHEABDOMINALWALL
Thepyramidalisisasmall,insignificanttriangularmuscle
thatisabsentinapproximately20%ofpeople.
Therectussheathisthestrong,incompletefibrouscompartmentof
therectusabdominisandpyramidalismuscles
THENERVESOFTHEABDOMINALWALL
NERVESOFANTEROLATERALABDOMINALWALL:
•  Thoraco-abdominalnerves
thesenerves
•  Lateral(thoracic)cutaneousbranches
communicatewitheach
•  Subcostalnerve
other
•  Iliohypogastricandilio-inguinalnerves
T10suppliestheskin
aroundtheumbilicus
THEVESSELSOFTHEABDOMINALWALL
Theprimarybloodvessels(arteriesandveins):
•  Superiorepigastricvesselsandbranchesofthemusculophrenic
vesselsfromtheinternalthoracicvessels.
•  Inferiorepigastricanddeepcircumflexiliacvesselsfromthe
externaliliacvessels.
•  Superficialcircumflexiliacandsuperficialepigastricvesselsfrom
thefemoralarteryandgreatersaphenousvein,respecOvely.
•  Posteriorintercostalvesselsofthe11thintercostalspaceandthe
anteriorbranchesofsubcostalvessels.
THEANTERIORABDOMINALWALL
LYMPHATICSINTHEREGIONABOVETHEUMBILICUS
•  drainintotheaxillarylymphnodes.
LYMPHATICSINTHEREGIONBELOWTHEUMBILICUS
•  drainintothesuperficialinguinalnodes.
SUPERFICIALINGUINALLYMPHNODES
•  receivelymphfromthelowerabdominalwall,bubocks,penis,
scrotum,labiummajus,andthelowerpartsofthevaginaandanal
canal.Theirefferentvesselsprimarilyentertheexternaliliacnodes
and,ulOmately,thelumbar(aorOc)nodes.
THEPOSTERIORABDOMINALWALL
POSTERIORABDOMINALWALL
THEPOSTERIORABDOMINALWALL
Theposteriorabdominalwall:
•  Fivelumbarvertebrae
•  Posteriorabdominalwallmuscles
•  Diaphragm
•  Fascia
•  Lumbarplexus
•  Fat,nerves,vessels(e.g.,aortaandIVC),andlymphnodes.
THEPOSTERIORABDOMINALWALL
Theposteriorabdominalwalliscoveredwiththelayerof
endoabdominalfasciathatliesbetweentheparietalperitoneumand
themuscles.
Thethoracolumbarfasciaisanfascialcomplexabachedtothe
vertebralcolumnmediallyandhasposterior,middle,andanterior
layerswithmusclesenclosedbetweenthem.
THEPOSTERIORABDOMINALWALL
Themusclesoftheposteriorabdominalwall:
•  Psoasmajor:passinginferolaterally.
•  Iliacus:lyingalongthelateralsidesoftheinferiorpartofthepsoas
major.
•  Quadratuslumborum:lyingadjacenttothetransverseprocesses
ofthelumbarvertebraeandlateraltosuperiorpartsofthepsoas
major.
THEPOSTERIORABDOMINALWALL
PSOASMAJOR
•  lieslateraltothelumbarvertebrae
•  passesinferolaterally
•  deeptotheinguinalligament
•  lumbarplexusisembeddedintheposteriorpartofthepsoas
major
ILIACUS
•  liesalongthelateralsideoftheinferiorpartofthepsoasmajor
•  psoasminorandiliacusmusclesmergeinferiorly;collecOvelyform
iliopsoasmuscle
QUADRATUSLUMBORUM
•  thequadrilateralquadratuslumborumformsathickmuscular
sheet
THEPOSTERIORABDOMINALWALL
VESSELSOFPOSTERIORABDOMINALWALL
THEPOSTERIORABDOMINALWALL
ABDOMINALAORTA:
•  beginsattheaorDchiatusinthediaphragmattheleveloftheT12
vertebra
•  endsattheleveloftheL4vertebrabydividingintotherightand
le\commoniliacarteries
ItdescendsanteriortothebodiesoftheT12–L4vertebrae
Thecommoniliacarteriesdivergeandruninferolaterally,following
themedialborderofthepsoasmusclestothepelvicbrim-divide
intotheinternalandexternaliliacarteries.
•  Theinternaliliacarteryentersthepelvis.
•  Theexternaliliacarteryfollowstheiliopsoasmuscle,givesriseto
theinferiorepigastricanddeepcircumflexiliacarteries
THEPOSTERIORABDOMINALWALL
RELATIONSOFABDOMINALAORTA:
•Celiacplexusandganglion
•Bodyofthepancreasandsplenicvein
•Lejrenalvein
•Horizontalpartoftheduodenum
•CoilsofsmallintesOne
RELATIONSOFABDOMINALAORTA:
Ontheright,theaortaisrelatedtotheazygosvein,cisternachyi,
thoracicduct,rightcrusofthediaphragm,andrightceliac
ganglion.
Onthele\,theaortaisrelatedtothelejcrusofthediaphragmand
thelejceliacganglion.
THEPOSTERIORABDOMINALWALL
BRANCHESOFTHEABDOMINALAORTA
THEPOSTERIORABDOMINALWALL
VEINSOFPOSTERIORABDOMINALWALL
TheveinsoftheposteriorabdominalwallaretributariesoftheIVC,
exceptforthele\tesDcularorovarianvein,whichentersthelej
renalveininsteadofenteringtheIVC
TheIVCreturnsbloodfromthe:
•  lowerlimbs,
•  mostoftheback,
•  abdominalwalls,
•  abdominopelvicviscera.
THEPOSTERIORABDOMINALWALL
Bloodfromtheabdominalviscerapassesthroughtheportalvenous
systemandtheliverbeforeenteringtheIVCviathehepaDcveins.
Theinferiorvenacava(IVC)beginsanteriortotheL5vertebrabythe
unionofthecommoniliacveins.
TheIVCleavestheabdomenbypassingthrough
thecavalopeninginthediaphragmandentersthethoraxattheT8
vertebrallevel.
THEPOSTERIORABDOMINALWALL
TheIVCcollectsbloodfromthelowerlimbsandnon-portalblood
fromtheabdomenandpelvis.
ThetributariesoftheIVCcorrespondtothepairedvisceraland
parietalbranchesoftheabdominalaorta.
AllthebloodfromthegastrointesDnaltractiscollectedbythe
hepaOcportalsystemandpassesthroughthehepaOcveinstotheIVC.
Theveinsthatcorrespondtotheunpairedvisceralbranchesof
theaortaareinsteadtributariesofthehepaAcportalvein.
THEPOSTERIORABDOMINALWALL
Thebranchescorrespondingtothepairedvisceralbranchesofthe
abdominalaortaincludethe:
•  rightsuprarenalvein,
•  rightandlejrenalveins,
•  rightgonadal(tesOcularorovarian)vein.
TheleBsuprarenalandgonadalveinsdrainindirectlyintotheIVC
becausetheyaretributariesoftheleBrenalvein.
THEPOSTERIORABDOMINALWALL
LYMPHATICVESSELS
LymphaOcvesselsandlymphnodesliealongtheaorta,IVC,andiliac
vessels.
CISTERNACHYLI
Isthelowerdilatedendofthethoracicductandliesjusttotheright
andposteriortotheaorta,usuallybetweentwocruraofthe
diaphragm.
IsformedbytheintesOnalandlumbarlymphtrunks.
ThethoracicductascendsthroughtheaorOchiatusinthediaphragm
intotheposteriormediasOnum,whereitcollectsmoreparietaland
visceraldrainage,parOcularlyfromthelejupperquadrantofthebody.
THEPOSTERIORABDOMINALWALL
LYMPHNODESRELATEDTOTHEAORTA
1.PreaorDcNodes
Includetheceliac,superiormesenteric,andinferiormesentericnodes;
drainthelymphfromtheGItract,spleen,pancreas,gallbladder,and
liver;andtheirefferentvesselsformtheintesOnaltrunk.
2.ParaaorDc,Lumbar,orLateralAorDcLymphNodes
Drainlymphfromthekidneys,suprarenalglands,testesorovaries,
uterus,anduterinetubes;receivelymphfromthecommon,internal,
orexternaliliac;andtheirefferentvesselsformtherightandlej
lumbartrunks.
THEABDOMEN
•  ABDOMINALCAVITY
•  ANTEROLATERALANDPOSTERIORABDOMINALWALL
•  INGUINALCANAL
THEINGUINALREGION
INGUINALREGION
Theinguinalregion(groin)extendsbetweentheASISandpubic
tubercle.Itisimportant:
•  structuresexitandentertheabdominalcavity
•  pathwaysofexitandentrancearepotenOalsitesofherniaOon
INGUINAL(HESSELBACH’S)TRIANGLE
Isboundedmediallybythelineasemilunaris(lateraledgeofthe
rectusabdominis),laterallybytheinferiorepigastricvessels,and
interiorlybytheinguinalligament.
INGUINAL(HESSELBACH’S)TRIANGLE
IsanareaofpotenOalweaknessandhenceisacommonsiteofa
directinguinalhernia.
THEINGUINALREGION
INGUINALREGION
TheinguinalligamentisadensebandconsOtuOngtheinferiormost
partoftheexternalobliqueaponeurosis.
Theiliopubictractisthethickenedinferiormarginofthetransversalis
fascia,whichappearsasafibrousbandrunning
parallelandposterior(deep)totheinguinalligament.
Theinguinalligamentandiliopubictractspananareaofinnate
weaknessinthebodywallintheinguinalregioncalledthe
myopecDnealorifice
THEINGUINALREGION
INGUINALCANAL
TheinguinalcanalisformedinrelaOontotherelocaOonofthetesOs
duringfetaldevelopment.Itliesparallelandsuperiortothemedial
halfoftheinguinalligament-approximately4cmlong.
ThemainoccupantoftheinguinalcanalisthespermaDccordin
malesandtheroundligamentoftheuterusinfemales.
TheinguinalcanalalsocontainsbloodandlymphaOcvesselsandthe
ilio-inguinalnerveinbothsexes.
THEINGUINALREGION
Theinguinalcanalhasanopeningateachend:
•  thedeep(internal)inguinalringistheentrancetotheinguinal
canal.Itislocatedsuperiortothemiddleoftheinguinalligament
andlateraltotheinferiorepigastricartery
•  thesuperficial(external)inguinalringistheexitbywhichthe
spermaOccordinmales,ortheroundligamentinfemales,emerges
fromtheinguinalcanal
Thelateralcrusabachestothepubictubercle,andthemedialcrus
abachestothepubiccrest.
THEINGUINALREGION
Theinguinalcanalhastwowalls(anteriorandposterior),
aroof,andafloor.
ANTERIORWALL:
formedbytheexternal
obliqueaponeurosis
throughoutthelengthofthe
canal;itslateralpartis
reinforcedbymusclefibersof
theinternaloblique.
POSTERIORWALL:formedbythe
transversalisfascia.Its
medialpartisreinforcedbypubic
abachmentsoftheinternaloblique
andtransversusabdominis
aponeuroses-inguinalfalx.
THEINGUINALREGION
ROOF:formedlaterallybythe
transversalisfascia,centrally
bymusculo-aponeuroOcarches
oftheinternalobliqueand
transversusabdominis,and
mediallybythemedialcrusof
theexternalobliqueaponeurosis.
FLOOR:formedlaterallybythe
iliopubictract,centrallybyguber
formedbytheinfoldedinguinal
ligament,andmediallybythe
lacunarligament.
THEINGUINALREGION
1.Anteriorwall:aponeurosesoftheexternalobliqueandinternal
obliquemuscles.
2.Posteriorwall:aponeurosisofthetransverseabdominalmuscle
andtransversalisfascia.
3.Superiorwall(roof):archingfibersoftheinternalobliqueand
transversemuscles.
4.Inferiorwall(floor):inguinalandlacunarligaments.
THEINGUINALREGION
Mostgroinhernias:
•  inmalespasssuperiortotheiliopubictract(inguinalhernias),
•  whereasmostpassinferiortoitinfemales(femoralhernias).
Aninguinalherniaisaprotrusionofparietalperitoneumandviscera,
suchasthesmallintesOne,throughanormalorabnormalopening
fromthecavityinwhichtheybelong.
Themajorityofabdominalherniasoccurintheinguinalregion.
Inguinalherniasaccountfor75%ofabdominalhernias.
THEINGUINALREGION
Thetwotypesofinguinalherniaaredirectandindirectinguinal
hernias.Morethantwothirdsareindirecthernias.
Indirectinguinalherniasdevelopattheinternalinguinalringandare
lateraltotheinferiorepigastricartery.