the abdomen - imulimul.pl/system/files/3. intestine rectum aorta vena cava.pdf · the abdomen •...

THEABDOMEN

•  SMALLINTESTINE•  LARGEINTESTINE•  RECTUM•  ABDOMINALAORTA•  INFERIORVENACAVA

THESMALLINTESTINE

THESMALLINTESTINE:•  IsthelongestpartofthegastrointesAnaltract-lengthof5metres

(3–7metres)inthelivingadult•  Consistsoftheduodenum,jejunum,andileum

•  ExtendsfromthepyloricopeningtotheileocecaljuncAon•  IsthelocaAonofcompletedigesAonandabsorpAonofmostofthe

productsofdigesAonandwater,electrolytes,andmineralssuchascalciumandiron

THESMALLINTESTINE

DUODENUMquickreview

THEDUODENUM

TheduodenumpursuesaC-shapedcoursearoundtheheadofthepancreas.

Itbeginsatthepylorusontherightsideandendsattheduodenojejunalflexure(juncAon)ontheleVside.

THEDUODENUM

SUPERIOR(FIRST)PARTOFTHEDUODENUM:•  L1level•  proximal2cmhasamesenteryandismobile,calledtheampulla

•  distal3cm(andtheotherthreepartsoftheduodenum)haveno

mesenteryandareimmobile-theyareretroperitoneal

•  peritoneumcoversanterioraspect

•  itisbareofperitoneumposteriorly,exceptfortheampulla

•  hepatoduodenalligament(partofthelesseromentum)a[achesto

theproximalpart

THEDUODENUM

DESCENDING(SECOND)PART:•  alongtherightsidesoftheL1–L3vertebrae•  liestotherightofandparalleltotheIVC•  thebileandmainpancreaAcductsenteritsposteromedialwall

•  isenArelyretroperitoneal•  anteriorsurfaceofitsproximalanddistalthirdsiscoveredwith

peritoneum

•  peritoneumreflectsfromitsmiddlethirdtoformthedouble-

layeredmesenteryofthetransversecolon,thetransverse

mesocolon

THEDUODENUM

INFERIOR(THIRD)PART:•  passingovertheIVC,aorta,andL3•  iscrossedbytheSMA•  posteriorly:rightpsoasmajor,IVC,aorta,andtherighttesAcularor

ovarianvessels•  anteriorsurfaceiscoveredwithperitoneum(exceptwhereitis

crossedbythesuperiormesentericvessels)

THEDUODENUM

Ascending(fourth)part:•  runssuperiorlyfromL3–L2vertebra•  runsalongtheleVsideoftheaorta•  supportedbythea[achmentofasuspensorymuscleofthe

duodenum(ligamentofTreitz)

•  anteriorsurfaceiscoveredwithperitoneum

THEDUODENUM

THEJEJUNUM

THEJEJUNUM

THEJEJUNUM

Thejejunumandileum,6–7mlong,occupythecentralandlowerpartsoftheabdominalcavityandusuallyliewithintheboundaryformedbytheabdominalcolon.

ThereisnocleardisAncAonbetweenthetwoparts,butthereisagradualchangeinmorphologyfromtheproximaltodistalendsofthesmallbowel.

•  thejejunumbeginsattheduodenojejunalflexure•  thejejunum-proximal2/5•  theileum–distal3/5•  theileumendsattheileocecaljuncNon

THEJEJUNUM

MostofthejejunumliesintheleVupperquadrant(LUQ)Mostoftheileumliesintherightlowerquadrant(RLQ)

THEJEJUNUM

Themesenterya[achesthejejunumandileumtotheposteriorabdominalwall-rootofthemesentery(15cmlong).

Therootofthemesentery:•  directedobliquely•  inferiorly•  andtotheright

FromtheduodenojejunaljuncNonontheleVsideofvertebraL2totheileocolicjuncNonandtherightsacro-iliacjoint.

THEJEJUNUMTherootofthemesenterycrossesthe:•  ascendingandinferiorpartsoftheduodenum,•  abdominalaorta,•  IVC,•  rightureter,•  rightpsoasmajor,

•  righttesAcularorovarianvessels.

THEJEJUNUMBetweenthetwolayersofthemesenteryarethe:•  superiormesentericvessels,•  lymphnodes,•  avariableamountoffat,•  autonomicnerves.

TheSMAsuppliesthejejunumandileumviajejunalandilealarteries

TheSMAusuallyarisesfromtheabdominal

aortaattheleveloftheL1vertebra

-1cminferiorceliac

trunk.

TheSMArunsbetweenthelayersofthemesentery,

sending15–18branchestothejejunumandileum

THEJEJUNUM

Thearteriesunitetoformloopsorarches,calledarterialarcades,

whichgiverisetostraightarteries,calledvasarecta

TheSMVdrainsthejejunumandileum.TheSMVendsposteriortotheneckofthepancreas,whereituniteswiththesplenicveintoformthehepaNcportalvein

SpecializedlymphaAcvesselsintheintesNnalvillithatabsorbfatarecalledlacteals.

THEJEJUNUM

Withinthemesentery,thelymphpassessequenAallythroughthreegroupsoflymphnodes:•  juxta-intesNnallymphnodes:locatedclosetotheintesAnalwall.•  mesentericlymphnodes:sca[eredamongthearterialarcades.•  superiorcentralnodes:locatedalongtheproximalpartofthe

SMA.EfferentlymphaAcvesselsfromthemesentericlymphnodesdraintothesuperiormesentericlymphnodes.LymphaAcvesselsfromtheterminalileumfollowtheilealbranchoftheileocolicarterytotheileocoliclymphnodes.

THEJEJUNUM

TheinnervaNonofthesmallintesNneisbytheentericnervoussystem,whichinthesmallintesAneconsistsofthe:•  submucosalplexusofMeissnerand•  myentericplexusofAuerbach.

THEJEJUNUM

SYMPATHETICPreganglionicneuronalcellbodiesarelocatedintheintermediolateralcellcolumnofthespinalcord(T8–12).Preganglionicaxonsformthe:•  greatersplanchnicnerve,•  lessersplanchnicnerve,•  leastsplanchnicnerve.

SYMPATHETICPostganglionicneuronalcellbodiesarelocatedintheceliacganglionandsuperiormesentericganglion.

THEJEJUNUM

PARASYMPATHETICPreganglionicneuronalcellbodiesarelocatedinthedorsalnucleusofthevagus.

PreganglionicaxonsruninCNXandreachthesmallintesAneviatheposteriorvagaltrunk.Postganglionicneuronalcellbodiesarelocatedintheentericnervoussystem;someofthesearethe“tradiAonal”postganglionicparasympatheAcneuronsthatreleaseAChasaneurotransmi[er.

Thepostganglionicaxonsterminateonmucosalglandsandsmoothmuscle.

THEJEJUNUM

SympatheNcsAmulaAonreducesperistalAcandsecretoryacAvityoftheintesAneandactsasavasoconstrictor,reducingorstoppingdigesAonandmakingblood(andenergy)availablefor“fleeingorfighAng.”

ParasympatheNcsAmulaAonincreasesperistalAcandsecretoryacAvityoftheintesAne,restoringthedigesAonprocessfollowingasympatheAcreacAon.

THEJEJUNUM

ThesmallintesAnealsohassensory(visceralafferent)fibers.TheintesAneisinsensiAvetomostpainsAmuli,includingcuingandburning;however,itissensiAvetodistensionthatisperceivedascolic(“intesAnalcramps”).

THEABDOMEN


THELARGEINTESTINE

ThelargeintesNneconsistsofthe:•  cecum•  appendix•  ascending•  transverse•  descending•  sigmoidcolon•  rectum•  analcanal

THELARGEINTESTINE

•  ExtendsfromtheileocecaljuncNontotheanusandisapproximately1.5m(5V)long.

•  FuncAonstoconverttheliquidcontentsoftheileumintosemisolidfecesbyabsorbingwater,salts,andelectrolytes.

THELARGEINTESTINE

ThelargeintesNnecanbedisAnguishedfromthesmallintesAneby:•  Omentalappendices:small,fa[y,omentum-likeprojecAons.•  Teniaecoli:threedisAnctlongitudinalbands:1.mesocolictenia,to

whichthetransverseandsigmoidmesocolonsa[ach;2.omentaltenia,towhichtheomentalappendicesa[ach;and3.freetenia,towhichneithermesocolonsnoromentalappendicesarea[ached.

•  Haustra:sacculaAonsofthewallofthecolonbetweentheteniae•  Amuchgreatercaliber(internaldiameter).

THELARGEINTESTINE

Theteniaecoli,thickenedbandsofsmoothmusclerepresenAngmostofthelongitudinalcoat,beginatthebaseoftheappendixasthethicklongitudinallayeroftheappendixseparatesintothreebands.

ThececumisthefirstpartofthelargeintesAneandisablindintesAnalpouch.

Itliesintheiliacfossaoftherightlowerquadrantoftheabdomen

Itmaybedisplacedfromtheiliacfossa,butitiscommonlyboundtothelateralabdominalwallbyoneormorececalfoldsofperitoneum

THELARGEINTESTINE

Theilealorificeentersthececumbetweenileocoliclips(superiorandinferior),foldsthatmeetlaterallyformingridgescalledthefrenulaoftheilealorifice.

TheappendixisablindintesAnaldiverAculum(6–10cminlength)thatcontainsmassesoflymphoidAssue.

TheappendixhasashortTRIANGULARmesentery,themeso-appendix

TheposiAonoftheappendixisvariable,butitisusuallyretrocecal

THELARGEINTESTINE

Thearterialsupplyofthececumisfromtheileocolicartery,theterminalbranchoftheSMA.

Theappendicularartery,abranchoftheileocolicartery,suppliestheappendix.

VenousdrainagefromthececumandappendixflowthroughatributaryoftheSMV,theileocolicvein.

THELARGEINTESTINE

LymphaNcdrainageofthececumandappendixpassestolymphnodesinthemeso-appendixandtotheileocoliclymphnodesthatliealongtheileocolicartery.

ThenervesupplytothececumandappendixderivesfromthesympatheAcandparasympatheAcnervesfromthesuperiormesentericplexus.

THELARGEINTESTINE

Thecolonhas4parts:•  ascending•  transverse•  descending•  andsigmoid.

Theascendingcolonpassessuperiorlyontherightsideoftheabdominalcavityfromthececumtotherightlobeoftheliver,whereitturnstotheleVattherightcolicflexure-hepaAcflexure.

THELARGEINTESTINE

ThearterialsupplytotheascendingcolonandrightcolicflexureisfrombranchesoftheSMA,theileocolicandrightcolicarteries.

VenousdrainagefromtheascendingcolonflowsthroughtributariesoftheSMV,theileocolicandrightcolicveins.

THELARGEINTESTINE

Thetransversecolonisthethird,longest,andmostmobilepartofthelargeintesAne.FromtherightcolicflexuretotheleVcolicflexure.

ThedescendingcolonisbetweentheleVcolicflexureandtheleViliacfossa,whereitisconAnuouswiththesigmoidcolon.

THELARGEINTESTINE

Thele_colicflexure(splenicflexure)isusually:•  moresuperior,•  moreacute,•  lessmobile.

Themesenteryofthetransversecolon(transversemesocolon)isadherenttoorfusedwiththeposteriorwalloftheomentalbursa.

Therootofthetransversemesocolonliesalongtheinferiorborderofthe

pancreasandisconAnuouswiththeparietal

peritoneumposteriorly.

THELARGEINTESTINE

Intallthinpeople,thetransversecolonmayextendintothepelvis

Thearterialsupplyofthetransversecolonismainlyfromthemiddlecolicartery,abranchoftheSMA.

Thearterialsupplyofthetransversecolonismainlyfromthemiddlecolicartery,abranchoftheSMA.ThetransversecolonmayalsoreceivearterialbloodfromtherightandleVcolicarteriesviaanastomoses.

THELARGEINTESTINE

VenousdrainageofthetransversecolonisthroughtheSMV.

ThelymphaNcdrainageofthetransversecolonistothemiddlecoliclymphnodes,whichinturndraintothesuperiormesentericlymphnodes.

THELARGEINTESTINE

Theperitoneumcoversthe

descendingcolonanteriorlyand

laterally.Thearterialsupplyofthedescendingisfromthele_colic,branchesoftheIMA.

VenousdrainagefromthedescendingcolonisprovidedbytheIMV,flowingusuallyintothesplenicveinandthenthehepaAcportalveinonitswaytotheliver.

THELARGEINTESTINE

Thesigmoidcolon,characterizedbyitsS-shapedloopofvariablelength,linksthedescendingcolonandtherectum.

Thesigmoidcolonhasalongmesentery,thesigmoidmesocolon,andthereforehasconsiderablefreedomofmovement

Theomentalappendicesofthesigmoidcolonarelong.

Thearterialsupplyofthesigmoidcolonisfromthesigmoidarteries,branchesoftheIMA.

THELARGEINTESTINE

TheSMAsupplyingbloodtotheleVcolicflexure-derivedfromtheembryonicmidgut.TheIMAsupplyingbloodfromtheleVcolicflexure-derivedfromtheembryonichindgut.

VenousdrainagefromthesigmoidcolonisprovidedbytheIMV,flowingusuallyintothesplenicveinandthenthehepaAcportalveinonitswaytotheliver.

LymphaNcdrainagefromthedescendingcolonandsigmoidcolonisconductedthroughvesselspassingtotheepicolicandparacolicnodes,andthenthroughtheintermediatecoliclymphnodesalongtheleVcolicartery.

THELARGEINTESTINE

ThesympatheNcnervesupplyofthedescendingandsigmoidcolonisfromthelumbarpartofthesympatheNctrunkvialumbar(abdominopelvic)splanchnicnerves.

TheparasympatheNcnervesupplyisfromthepelvicsplanchnicnervesviatheinferiorhypogastric(pelvic)plexusandnerves(S2-S4).

THEABDOMEN


THERECTUM

TherectumisconAnuouswiththesigmoidcolonatthelevelofS3vertebra,isconAnuousinferiorlywiththeanalcanal.

Therectumisthefixed(primarilyretroperitonealandsubperitoneal)terminalpartofthelargeintesAne.

THEABDOMEN


THEABDOMINALAORTA

Theabdominalaortabeginsat

theaorNchiatusinthediaphragmatthe

leveloftheT12vertebra

andendsattheleveloftheL4vertebra

bydividingintotherightandle_common

iliacarteries.

Theabdominalaortaisapproximately13cminlength.

Thebranchesoftheaortaaredescribedas:•  anterior,•  lateraland•  dorsal.

THEABDOMINALAORTA

Theanteriorandlateralbranchesaredistributedtotheviscera.Thedorsalbranchessupplythebodywall,vertebralcolumn,vertebralcanalanditscontents.

Theaortaterminatesbydividingintotherightandle_commoniliacarteries.

THEABDOMINALAORTA

Thebranchesoftheaorta:•  inferiorphrenica.•  celiactrunk•  superiormesenterica.•  middlesuprarenala.•  renala.•  tesAcularorovariana.•  fourlumbaraa.•  inferiormesenterica.•  mediansacrala.•  commoniliaca.

THEABDOMINALAORTATHEBRANCHESOFTHEAORTAINFERIORPHRENICA.Pairedarteriesthatsupplythediaphragm,whichtheyenterfrombelow.Itsuppliesdiaphragmandgivessuperiorsuprarenalarteries.CELIACTRUNKCommonstemoftheleVgastric,commonhepaAcandsplenicarteriesatthelevelofT12.Anteriortotheceliactrunkliesthelessersac.Theceliacplexussurroundsthetrunk,sendingextensionsalongitsbranches.Thebodyofthepancreasandthesplenicveinareinferiortotheceliactrunk.

THEABDOMINALAORTATHEBRANCHESOFTHEAORTASUPERIORMESENTERICARTERYUnpairedbranchoftheaortaarisingabout1cmbelowtheceliactrunk.Itextendsfrombehindthepancreastotheuncinateprocessandpasseswithitsbranchesintothemesenteryandmesocolon.MIDDLESUPRARENALARTERYArisesfromthelateralaspectoftheabdominalaorta,levelwiththesuperiormesentericarteryandsuppliesthesuprarenalgland.RENALARTERYThelargestbranchesoftheabdominalaorta,itarisesfromtheaortainfrontofL1anddividesintoseveralbrancheswhichenterthekidney.

THEABDOMINALAORTATHEBRANCHESOFTHEAORTARENALARTERYTherightislongerandusuallyarisesslightlyhigherthantheleV.Itpassesposteriortotheinferiorvenacava,rightrenalvein,headofthepancreasandsecondpartoftheduodenum.TESTICULAROROVARIANARTERYThegonadalarteriesaretwolongvessels,thatarisefromtheaortainferiortotherenalarteries.Eachpassesinferolaterallyundertheparietalperitoneumonpsoasmajor.FOURLUMBARARTERIESTheyarisefromtheposterolateralaspectoftheaorta,whichcorrespondtotheintercostalarteries.

THEABDOMINALAORTATHEBRANCHESOFTHEAORTAINFERIORMESENTERICARTERYItarisesfromtheanteriororleVanterolateralaspectoftheaorta.Theinferiormesentericarteryisusuallysmallerincalibrethanthesuperiormesentericartery.MEDIANSACRALARTERYArisesfromtheposterioraspectoftheaortaali[leaboveitsbifurcaAon.Itdescendsinthemidlineandendsinthecoccygealbody.COMMONILIACARTERYItextendsfromthebifurcaAonofthedescendingaortaatL4/L5toitsdivisionintotheinternalandexternaliliacarteriesinfrontofthesacroiliacjoint.

THEABDOMINALAORTA

Thebranchesoftheaorta:•  inferiorphrenica.•  celiactrunk•  superiormesenterica.•  middlesuprarenala.•  renala.•  tesAcularorovariana.•  fourlumbaraa.•  inferiormesenterica.•  mediansacrala.•  commoniliaca.

THEABDOMINALAORTA

Thecommoniliacarteriesdivergeandruninferolaterally,followingthemedialborderofthepsoasmusclestothepelvicbrim.•  Theinternaliliacarteryentersthepelvis.•  Theexternaliliacarteryfollowstheiliopsoasmuscle,givesriseto

theinferiorepigastricanddeepcircumflexiliacarteries

RELATIONSOFABDOMINALAORTA:•Celiacplexusandganglion•Bodyofthepancreasandsplenicvein•LeVrenalvein•Horizontalpartoftheduodenum•CoilsofsmallintesAne

RELATIONSOFABDOMINALAORTA:Ontheright,theaortaisrelatedtotheazygosvein,cisternachyi,thoracicduct,rightcrusofthediaphragm,andrightceliacganglion.Onthele_,theaortaisrelatedtotheleVcrusofthediaphragmandtheleVceliacganglion.

THEABDOMINALAORTA

THEABDOMEN


Theinferiorvenacava(IVC)beginsanteriortotheL5vertebrabytheunionofthecommoniliacveins.

THETHEINFERIORVENACAVA

TheIVCleavestheabdomenbypassingthroughthecavalopeninginthediaphragmandentersthethoraxattheT8vertebrallevel.

THETHEINFERIORVENACAVATHEINFERIORVENACAVATheinferiorvenacavaisformedbythejuncAonofthecommoniliacveinsanteriortothefiVhlumbarvertebralbody,ali[letoitsright.Itascendsanteriortothevertebralcolumn,totherightoftheaorta,andiscontainedinadeepgrooveontheposteriorsurfaceoftheliver.TheabdominalporAonoftheinferiorvenacavaisdevoidofvalves.

TRIBUTARIES•  thecommoniliacveinsatitsorigin•  lumbar,•  rightgonadal,•  renal,•  rightsuprarenal,•  inferiorphrenic,•  hepaAcveins



THEINFERIORVENACAVATheveinsoftheposteriorabdominalwallaretributariesoftheIVC,exceptforthele_tesNcularorovarianvein,whichenterstheleVrenalveininsteadofenteringtheIVC

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

BloodfromtheabdominalviscerapassesthroughtheportalvenoussystemandtheliverbeforeenteringtheIVCviathehepaNcveins.


TheIVCcollectsbloodfromthelowerlimbsandnon-portalbloodfromtheabdomenandpelvis.ThetributariesoftheIVCcorrespondtothepairedvisceralandparietalbranchesoftheabdominalaorta.

AllthebloodfromthegastrointesNnaltractiscollectedbythehepaAcportalsystemandpassesthroughthehepaAcveinstotheIVC.Theveinsthatcorrespondtotheunpairedvisceralbranchesoftheaortaareinsteadtributariesofthehepa9cportalvein.

Thebranchescorrespondingtothepairedvisceralbranchesoftheabdominalaortaincludethe:•  rightsuprarenalvein,•  rightandleVrenalveins,•  rightgonadal(tesAcularorovarian)vein.Thele:suprarenalandgonadalveinsdrainindirectlyintotheIVCbecausetheyaretributariesofthele:renalvein.


INTRAPERITONEALAND

RETROPERITONEALORGANS

THEPERITONEALCAVITY

INTRAPERITONEALANDRETROPERITONEALORGANS:•  Intraperitonealorgansaresuspendedbyamesenteryandare

almostcompletelyenclosedinvisceralperitoneum.Theseorgansaremobile.

•  RetroperitonealorgansareparAallycoveredononesidewith

parietalperitoneumandareimmobileorfixedorgans.Manyretroperitonealorganswereoriginallysuspendedbyamesenteryandbecomesecondarilyretroperitoneal.

THEPERITONEALCAVITY

INTRAPERITONEALANDRETROPERITONEALORGANS:MajorlntraperitonealOrgans(suspendedbyamesentery)•  Stomach•  Liverandgallbladder•  Spleen•  Duodenum,1stpart•  Tailofpancreas•  Jejunum•  Ileum•  Appendix•  Transversecolon•  Sigmoidcolon

THEPERITONEALCAVITY

INTRAPERITONEALANDRETROPERITONEALORGANS:MajorSecondaryRetroperitonealOrgans(lostamesenteryduringdevelopment)•  Duodenum,2ndand3rdparts•  Head,neck,andbodyofpancreas•  Ascendingcolon•  Descendingcolon•  Upperrectum

THEPERITONEALCAVITY

INTRAPERITONEALANDRETROPERITONEALORGANS:MajorPrimaryRetroperitonealOrgans(neverhadamesentery)•  Kidneys•  Adrenalglands•  Ureters•  Aorta•  lnferiorvenacava•  Lowerrectum•  Analcanal

THEPERITONEALCAVITYADULTSTRUCTURESDERIVEDFROMEACHOFTHE3DIVISIONSOFTHEPRIMITIVEGUTTUBEFOREGUTArtery:celiacParasympatheNcinnervaNon:vagusnervesSympatheNcinnervaNon:•  preganglionics:thoracicsplanchnicnerves,T5-T9•  postganglioniccellbodies:celiacganglionReferredPain:EpigastriumForegutDerivaNves:•  Esophagus•  Stomach•  Duodenum(firstandsecondparts)•  Liver•  Pancreas•  Biliaryapparatus•  Gallbladder

THEPERITONEALCAVITYADULTSTRUCTURESDERIVEDFROMEACHOFTHE3DIVISIONSOFTHEPRIMITIVEGUTTUBEMIDGUTArtery:superiormesentericParasympatheNcinnervaNon:vagusnervesSympatheNcinnervaNon:-Preganglionics:thoracicsplanchnicnerves,T9-T12-Postganglioniccellbodies:superiormesentericganglionReferredPain:UmbilicalMidgutDerivaNves•  Duodenum(second,third,andfourthparts)•  Jejunum•  Ileum•  Cecum•  Appendix•  Ascendingcolon•  Transversecolon(proximaltwo-thirds)

THEPERITONEALCAVITYADULTSTRUCTURESDERIVEDFROMEACHOFTHE3DIVISIONSOFTHEPRIMITIVEGUTTUBEHINDGUTArtery:inferiormesentericParasympatheNcinnervaNon:pelvicsplanchnicnervesSympatheNcinnervaNon:•  preganglionics:lumbarsplanchnicnerves,L1-L2•  postganglioniccellbodies:inferiormesentericganglionReferredPain:HypogastriumHindgutDerivaNves•  Transversecolon(distalthirdsplenicflexure)•  Descendingcolon•  Sigmoidcolon•  Rectum•  Analcanal(abovepecAnateline)

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