Download the pelvis

THEPELVIS
VASCULARANDNERVOUSSYSTEM
SOMATICANDAUTONOMICNERVES
THEABDOMINALAORTA
Theabdominalaortabeginsat
theaor9chiatus
inthediaphragmatthelevelofthe
T12vertebra
andendsatthe
levelofthe
L4vertebra
bydividingintothe
rightandleEcommoniliacarteries.
Theabdominalaortaisapproximately
13cminlength.
THEABDOMINALAORTA
Thebranchesoftheaorta
aredescribedas:
•  anterior,
•  lateraland
•  dorsal.
Theanteriorandlateral
branchesaredistributed
totheviscera.
Thedorsalbranches
supplythebodywall,
vertebralcolumn,
vertebralcanalandits
contents.
Thebranchesoftheaorta:
•  inferiorphrenica.
•  celiactrunk
•  superiormesenterica.
•  middlesuprarenala.
•  renala.
•  tesHcularorovariana.
•  fourlumbaraa.
•  inferiormesenterica.
•  mediansacrala.
•  commoniliaca.
THEABDOMINALAORTA
THEBRANCHESOFTHEAORTA
INFERIORPHRENICA.
Pairedarteriesthatsupplythediaphragm,whichtheyenterfrom
below.Itsuppliesdiaphragmandgivessuperiorsuprarenalarteries.
CELIACTRUNK
CommonstemoftheleKgastric,commonhepaHcandsplenic
arteriesatthelevelofT12.
Anteriortotheceliactrunkliestheomentalbursa.Theceliacplexus
surroundsthetrunk,sendingextensionsalongitsbranches.Thebody
ofthepancreasandthesplenicveinareinferiortotheceliactrunk.
Branches:
•  splenicartery
•  commonhepaHcartery
•  leKgastric
THEABDOMINALAORTA
THEBRANCHESOFTHEAORTA
CELIACTRUNK-SPLENICARTERY
Thisisthelargestbranchofthecoeliacaxisanditscourseisamong
themosttortuousinthebody.
Itlies:
•  posteriortotheomentalbursa,
•  anteriortotheleKkidney,
•  alongthesuperiorborderofthepancreas.
Thesplenicarterygivesoffvariousbranchestothepancreasinits
courseandgivesoffshortgastricarteriestothestomachjustpriorto
dividingorfromitsterminalbranches.
THEABDOMINALAORTA
THEBRANCHESOFTHEAORTA
CELIACTRUNK-HEPATICARTERY
AKeritsoriginfromthecoeliacaxis,thehepaHcarterypasses
anteriorlyandlaterallybelowtheepiploicforamentothe
upperaspectofthefirstpartoftheduodenum.
Itmaybesubdividedintothecommonhepa9cartery,fromthe
coeliactrunktotheoriginofthegastroduodenalartery,andthe
hepa9cartery‘proper’fromtheoriginofthegastroduodenalartery
toitsbifurcaHon.
THEABDOMINALAORTA
THEBRANCHESOFTHEAORTA
CELIACTRUNK-LEFTGASTRICARTERY
TheleKgastricarteryisthesmallestbranchofthecoeliacaxis.
Itrunsalongthelessercurvaturebetweenthetwoperitonealleaves
ofthelesseromentum.
SUPERIORMESENTERICARTERY
Unpairedbranchoftheaortaarisingabout1cmbelowtheceliac
trunk.Itextendsfrombehindthepancreastotheuncinate
processandpasseswithitsbranchesintothemesenteryand
mesocolon.
THEABDOMINALAORTA
THEBRANCHESOFTHEAORTA
MIDDLESUPRARENALARTERY
Arisesfromthelateralaspectoftheabdominalaorta,levelwiththe
superiormesentericarteryandsuppliesthesuprarenalgland.
RENALARTERY
Thelargestbranchesoftheabdominalaorta,itarisesfromtheaortain
frontofL1anddividesintoseveralbrancheswhichenterthekidney.
TherightislongerandusuallyarisesslightlyhigherthantheleK.It
passesposteriorto:theinferiorvenacava,rightrenalvein,headofthe
pancreasandsecondpartoftheduodenum.
TheleKrenalarteryarisesaliRlelowerdownandpassesbehindthe
leKrenalvein,thebodyofthepancreasandthesplenicvein.
THEABDOMINALAORTA
THEBRANCHESOFTHEAORTA
TESTICULAROROVARIANARTERY
Thegonadalarteriesaretwolongvessels,thatarisefromthe
aortainferiortotherenalarteries.Eachpassesinferolaterally
undertheparietalperitoneumonpsoasmajor.
Anteriortopsoasmajoritcrossesinfrontoftheureter.
FOURLUMBARARTERIES
Theyarisefromtheposterolateralaspectoftheaorta,which
correspondtotheintercostalarteries.
INFERIORMESENTERICARTERY
ItarisesfromtheanteriororleKanterolateralaspectoftheaorta.The
inferiormesentericarteryisusuallysmallerincalibrethanthesuperior
mesentericartery.
THEABDOMINALAORTA
THEBRANCHESOFTHEAORTA
MEDIANSACRALARTERY
ArisesfromtheposterioraspectoftheaortaaliRleaboveits
bifurcaHon.Itdescendsinthemidlineandendsinthecoccygealbody.
COMMONILIACARTERY
ItextendsfromthebifurcaHonofthedescendingaortaatL4toits
divisionintotheinternalandexternaliliacarteriesinfrontofthe
sacroiliacjoint.
Thecommoniliacarteriesdivergeandruninferolaterally,following
themedialborderofthepsoasmusclestothepelvicbrim.
•  Theinternaliliacarteryentersthepelvis.
•  Theexternaliliacarteryfollowstheiliopsoasmuscle,givesriseto
theinferiorepigastricanddeepcircumflexiliacarteries
THEABDOMINALAORTA
RELATIONSOFABDOMINALAORTA:
•Celiacplexusandganglion
•Bodyofthepancreasandsplenicvein
•LeKrenalvein
•Horizontalpartoftheduodenum
•CoilsofsmallintesHne
RELATIONSOFABDOMINALAORTA:
Ontheright,theaortaisrelatedtotheazygosvein,cisternachyi,
thoracicduct,rightcrusofthediaphragm,andrightceliac
ganglion.
RELATIONSOFABDOMINALAORTA:
OntheleE,theaortaisrelatedtotheleKcrusofthediaphragmand
theleKceliacganglion.
ARTERIESOFTHEPELVIS
VEINSOFTHEPELVIS
LYMPHATICDRAINAGEOFTHEPELVIS
INNERVATIONOFTHEPELVIS
ARTERIES
6mainarteriesenterthelesserpelvisoffemales:
•  thepairedinternaliliacandovarianarteries
•  theunpairedmediansacral
•  thesuperiorrectalarteries.
SincethetesHculararteriesDONOTenterthelesserpelvis,only4
mainarteriesenterthelesserpelvisofmales:
•  thepairedinternaliliac
•  theunpairedmediansacral
•  thesuperiorrectalarteries.
ARTERIES
ThecommonandexternaliliacvesselsandthelymphaHcswhich
drainthelowerlimbliealongthepelvicbrim.
Thetruepelviscontainstheinternaliliacarteriesandveinsandthe
lymphaHcswhichdrainthemajorityofthepelvicviscera.
TheabdominalaortabifurcatesintotherightandleKcommoniliac
arteriesanterolateraltotheleEsideoftheL4vertebralbody.
Thesearteriesdivergeastheydescendanddivideatthelevelofthe
sacroiliacjointintoexternalandinternaliliacarteriesatthelevelof
theIVdiscbetweentheL5andS1vertebrae
ARTERIES
Theexternaliliacarteryistheprincipalarteryofthelowerlimb.
Theinternaliliacarteryprovidestheprincipalsupplytothewalls
andvisceraofthepelvis,theperineumandtheglutealregion.
THERIGHTCOMMONILIACARTERY
ARTERIES
Itiscoveredbytheparietalperitoneum,whichseparatesitfromthe
coilsofthesmallintesHne.
TherightcommoniliacarterypassesobliquelyacrosspartoftheL4
andL5vertebralbodies.
Therightcommoniliacarteryiscrossedanteriorlybythe
sympatheHcramitothepelvicplexusand,atitsdivisionintointernal
andexternaliliacarteries,bytheureter.
Posteriorly,therightcommoniliacarteryisseparatedfromthe
fourthandfiKhlumbarvertebralbodiesbytherightsympatheHc
trunk,theterminalpartsofthecommoniliacveinsandthestartof
theinferiorvenacava,theobturatornerve,lumbosacraltrunkand
iliolumbarartery.
Laterally,theinferiorvenacavaandtherightcommoniliacveinlie
superiorlyandtherightpsoasmajorliesinferiorly.
THELEFTCOMMONILIACARTERY
TheleEcommoniliacarteryisshorterthantheright.
LyinganteriortotheleKcommoniliacarteryare:
•  thesympatheHcramitothepelvicplexus,
•  thesuperiorrectalartery
•  theureter.
PosteriortotheleKiliacarteryare:
•  thesympatheHctrunk,
•  theL4&L5vertebralbodies
•  theobturatornerve,
•  lumbosacraltrunk,
•  iliolumbarartery.
ARTERIES
ARTERIES
Theexternaliliacarteriesareoflargercalibrethantheinternaliliac
arteries.
Theexternaliliacarterydescendslaterallyalongthemedialborderof
psoasmajor,fromthecommoniliacbifurcaHontoapointmidway
betweentheASISandthesymphysispubis.
Theexternaliliacartery
entersthethighposteriorto
theinguinalligamentto
becomethefemoralartery.
InaddiHontotheexternaliliacandinternaliliacbranches,each
commoniliacarteryalsogivessmallbranchestotheperitoneum,
psoasmajor,ureter.
THEINTERNALILIACARTERY
ARTERIES
TheinternaliliacarterybeginsatthecommoniliacbifurcaHon,level
withthelumbosacralintervertebraldiscandanteriortothe
sacroiliacjoint.
ItdescendsposteriorlytothesuperiormarginofthegreatersciaHc
foramen.
Anteriortothearteryare:
•  ureter,
•  infemales,theovaryandfimbriatedendoftheuterinetube.
Posteriortothearteryare:
•  internaliliacvein,
•  lumbosacraltrunk,
•  sacroiliacjoint.
THEINTERNALILIACARTERY
ARTERIES
Lateralare:
•  externaliliacvein,betweenthearteryandpsoasmajor,
•  obturatornervelyinginferiortothevein.
AtthesuperiormarginofthegreatersciaHcforamendividesinto:
•  anteriortrunk,whichconHnuesinthesamelinetowardsthe
ischialspine,and
•  posteriortrunk,whichpassesbacktothegreatersciaHcforamen.
THEANTERIORTRUNKBRANCHESOFTHEINTERNALILIACARTERY
Thebranchesoftheanteriortrunkoftheinternaliliacarteryare:
•  superiorvesical,
•  inferiorvesical,
•  middlerectal,
•  vaginal,
•  obturator,
•  uterine,
•  internalpudendal
•  inferiorgluteal.
ARTERIES
THEANTERIORTRUNKBRANCHESOFTHEINTERNALILIACARTERY
ARTERIES
Thesuperiorvesicalarteryisthefirstlargebranchoftheanterior
trunk.Itliesonthelateralwallofthepelvisjust
belowthebrimandrunsanteroinferiorly.
Thesuperiorvesicalarterysuppliesthedistalendoftheureter,the
bladder,theproximalendofthevasdeferensandtheseminal
vesicles.
Theinferiorvesicalarterysuppliesthebladder,theprostate,the
seminalvesiclesandthevasdeferens.
Themiddlerectalarterymayariseindependentlyfromtheinternal
iliacartery.
Themiddlerectalarteryrunsintothelateralfascialcoveringsofthe
mesorectum.
THEANTERIORTRUNKBRANCHESOFTHEINTERNALILIACARTERY
ARTERIES
Thevaginalarteryisthehomologtotheinferiorvesicalarteryin
males.
Theobturatorarteryrunsanteroinferiorlyonthelateralpelvicwallto
theupperpartoftheobturatorforamen.
Inthepelvis,theobturatorarteryisrelatedlaterallytothefasciaover
obturatorinternusandiscrossedonitsmedialaspectbytheureter
and,inthemale,bythevasdeferens.
Theobturatornerveisabovetheartery,theobturatorveinbelowit.
Theobturatorarterysupplies:
•  pelvicmuscles,
•  nutrientarterytoilium,
•  headoffemur,
•  musclesofmedialcompartmentofthigh.
THEANTERIORTRUNKBRANCHESOFTHEINTERNALILIACARTERY
ARTERIES
TheuterinearteryisanaddiHonalbranchinfemales.Developmentally,it
isthehomologofthearterytotheductusdeferensinthemale.
Theuterinearterypassesdirectlysuperiortotheureter.
Theuterinearterydescendsonthelateralwallofthepelvis,anterior
totheinternaliliacartery,andpassesmediallyinbaseofbroad
ligamenttoreachthejuncHonoftheuterusandvagina.
Theinternalpudendalarteryarisesjustbelowtheoriginofthe
obturatorartery.
Theinternalpudendalarterydescendslaterallytotheinferiorrimof
thegreatersciaHcforamen,whereitleavesthepelvisbetween
piriformisandischiococcygeustoenterthegluteal
region.
THEANTERIORTRUNKBRANCHESOFTHEINTERNALILIACARTERY
ARTERIES
Theinternalpudendalarterycurvesaroundthedorsumoftheischial
spinetoentertheperineumbythelessersciaHcforamen.
Theinternalpudendalarterysuppliesmusclesandskin
ofanalandurogenitaltriangles,erecHlebodies.
Theinferiorglutealarteryisthelargerterminalbranchoftheanterior
internaliliactrunkandprincipallysuppliesthebuRockandthigh.
Theinferiorglutealarterydescendsposteriorly,anteriortothe
sacralplexusandpiriformisbutposteriortotheinternalpudendal
artery.
Theinferiorglutealarteryleavesthepelvisthroughtheinferiorpart
ofthegreatersciaHcforamen,inferiortothepiriformismuscle.
Theinferiorglutealarterysuppliesthemusclesandskinofthe
buRock,andtheposteriorsurfaceofthethigh.
THEANTERIORTRUNKBRANCHESOFTHEINTERNALILIACARTERY
ARTERIES
Beforebirth,theumbilicalarteriesarethemainconHnuaHonofthe
internaliliacarteries.
Beforebirth,theumbilicalarteriesarepassingalongthelateralpelvic
wallandthenascendingtheanteriorabdominalwalltoandthrough
theumbilicalringintotheumbilicalcord.
Theoccludedpartsformfibrouscordscalledthemedialumbilical
ligaments.
THEPOSTERIORTRUNKBRANCHESOFTHEINTERNALILIACARTERY
ARTERIES
Thebranchesoftheposteriortrunkoftheinternaliliacarteryare:
•  iliolumbar,
•  lateralsacral,
•  superiorglutealarteries.
Theiliolumbararteryisthefirstbranchoftheposteriortrunkand
ascendslaterallyanteriortothesacroiliacjointand
lumbosacralnervetrunk.
THEPOSTERIORTRUNKBRANCHESOFTHEINTERNALILIACARTERY
ARTERIES
Theiliolumbararterysupplies:
•  psoasmajorandquadratuslumborum
•  glutealandabdominalmuscles
•  iliacus
•  caudaequina
Thelateralsacralarteriesareusuallydouble,orifsingle,divide
rapidlyintosuperiorandinferiorbranches.
Thelateralsacralarteriessupplythepsoasmajorandquadratus
lumborummuscles.
Thesuperiorglutealarteryisthelargestbranchoftheinternaliliac
artery.
THEPOSTERIORTRUNKBRANCHESOFTHEINTERNALILIACARTERY
ARTERIES
Thesuperiorglutealarteryisleavingthepelvisbythegreater
sciaHcforamenabovepiriformisanddividingintosuperficialand
deepbranches.
Thesuperiorglutealarterysuppliespiriformis,obturatorinternus
andanutrientarterytotheilium.
THEOVARIANARTERY
ARTERIES
Theovarianarteryarisesfromtheabdominalaortainferiortothe
renalarterybutconsiderablysuperiortotheinferiormesenteric
artery.
Theovarianarteryrunsanteriortotheureterontheposterior
abdominalwall,usuallygivingbranchestoit.
Theovarianarterydescendsbehindtheperitoneum,andatthebrim
ofthepelviscrosseswiththeureterovertheexternaliliacarteryand
veintoenterthetruepelviccavity.
Inthetruepelviccavity,theovarianarteryturnsmediallyinthe
ovariansuspensoryligamentandsplitsintoabranchtothe
mesovariumthatsuppliestheovary,andabranchthatconHnuesinto
theuterinebroadligament,belowtheuterinetube,andsuppliesthe
tube.
THEMEDIANSACRALARTERY
ARTERIES
Themediansacralarteryisasmallunpairedarterythatusuallyarises
fromtheposteriorsurfaceoftheabdominalaorta,justsuperiortoits
bifurcaHon,butitmayarisefromitsanteriorsurface.
THESUPERIORRECTALARTERY
ThesuperiorrectalarteryisthedirectconHnuaHonofthe
inferiormesentericartery.
VEINS
Thetruepelviscontainsalargenumberofveinswhichdrainthepelvic
wallsandmostofthevisceracontainedwithinthepelvis,andwhich
carryvenousbloodfromtheglutealregion,hipandthigh.
Pelvicvenousplexusesareformedbytheinterjoiningveins
surroundingthepelvicviscera.
Thevariousplexuseswithinthelesserpelvis(rectal,vesical,prostaHc,
uterine,andvaginal)uniteandaredrainedmainlybytributariesofthe
internaliliacveins.
SomeofthemdrainthroughthesuperiorrectalveinintotheIMV,or
throughlateralsacralveinsintotheinternalvertebralvenous
plexus.
AddiHonalrelaHvelyminorpathsofvenousdrainagefromthelesser
pelvisincludetheparietalmediansacralveinand,infemales,the
ovarianveins.
THECOMMONILIACVEINS
VEINS
Thecommoniliacveinisformedbytheunionoftheexternaland
internaliliacveins,anteriortothesacroiliacjoints.
TherightcommoniliacveinisshorterandmorenearlyverHcal,lying
posteriorandthenlateraltoitsartery.
Therightcommoniliacveinascendsobliquelytoendattherightside
oftheL5vertebra,uniHngwiththecontralateralvesseltoformthe
IVC.
THEINTERNALILIACVEINS
TheinternaliliacveinsformsuperiortothegreatersciaHc
foramenandliepostero-inferiortotheinternaliliacarteries
Thetributariesoftheinternaliliacveinsare:
•  gluteal,
•  internalpudendal
•  obturatorveins,
•  lateralsacralveins,
•  middlerectal,
•  vesical,
•  uterine,
•  vaginal
veins
VEINS
Thelymphnodesinthepelvisaregroupedaroundthecommon,
externalandinternaliliacvessels.
Fourprimarygroupsofnodesare:
•  externaliliaclymphnodes:lieabovethepelvicbrim,alongthe
externaliliacvessels.
Theyreceivelymphmainlyfromtheinguinallymphnodes.
LYMPH
•  internaliliaclymphnodes:clusteredaroundtheanteriorand
posteriordivisionsoftheinternaliliacartery.
Theyreceivedrainagefromtheinferiorpelvicviscera,deepperineum,
andglutealregionanddrainintothecommoniliacnodes.
•  sacrallymphnodes:lieintheconcavityofthesacrum.
Theyreceivelymphfrompostero-inferiorpelvicviscera.
•  commoniliaclymphnodes:liesuperiortothepelvicbrim,along
thecommoniliacbloodvessels.
Theselymphnodesreceivedrainagefromthethreemaingroups
listedabove.Thesenodesbeginacommonroutefordrainagefrom
thepelvisthatpassesnexttothelumbarnodes.
NERVES
Thepelviscontainsthelumbosacralnervetrunk,thesacraland
coccygealplexusesandthepelvicpartsofthesympatheHcand
parasympatheHcsystems.
Theventralramiofthesacralandcoccygealspinalnervesformthe
sacralandcoccygealplexuses
Thesacralplexusisformedbythelumbosacraltrunk,
theS1-S3ventralramiandpartoftheS4ventralramus.
Thelumbarpartofthelumbosacraltrunkcontainspartof
theL4andtheL5ventralrami.
Thelumbarpartofthelumbosacraltrunkitappearsatthemedial
marginofpsoasmajor,anddescendsoverthepelvicbrimanteriorto
thesacroiliacjointtojointheS1ramus.
THESACRALPLEXUS
NERVES
Thesacralplexusliesagainsttheposteriorpelvicwallanteriorto
piriformis,posteriortotheinternaliliacvesselsandureter,andbehind
thesigmoidcolonontheleK.
Thesuperiorglutealvesselsruneitherbetweenthelumbosacraltrunk
andfirstsacralventralramusorbetweenthefirstandsecondsacral
rami.
Mostbranchesofthesacralplexusleavethepelvisthroughthe
greatersciaHcforamen.
Thetwomainnervesarisingfromthesacralplexus,thesciaHcand
pudendalnerves,lieexternaltotheparietalpelvicfascia.
Thescia9cnerveisthelargestnerveinthebody.Itisformedasthe
largeanteriorramiofspinalnervesL4–S3convergeontheanterior
surfaceofthepiriformis.
THESACRALPLEXUS
NERVES
Thescia9cnervedescendsbetweenthegreatertrochanterandischial
tuberosity,alongthebackofthethigh,dividingintotheHbialand
commonfibularnervesatavaryinglevelproximaltotheknee.
ThepudendalnervearisesfromtheventraldivisionsoftheS2,S3and
S4ventralramiandisformedjustabovethesuperior
borderofthesacrotuberousligamentandtheupperfibresof
ischiococcygeus.
Thepudendalnerveisthemainnerveoftheperineumandthechief
sensorynerveoftheexternalgenitalia.
Accompaniedbytheinternalpudendalartery,itleavesthepelvis
throughthegreatersciaHcforamenbetweenthepiriformisand
coccygeusmuscles.
THESACRALPLEXUS
NERVES
Thepudendalnervehooksaroundtheischialspineandsacrospinous
ligament.
Thepudendalnerveaccompaniestheinternalpudendalartery
throughthelessersciaHcforamenintothepudendal(Alcock’s)canal
onthelateralwalloftheischio-analfossa.
Thepudendalnervegivesrisetotheinferiorrectalnerve,the
perinealnerveandthedorsalnerveofthepenisorclitoris.
Thesuperiorglutealnerveleavesthepelvisthroughthe
greatersciaHcforamen,superiortothepiriformistosupply
musclesintheglutealregion.
TheinferiorglutealnerveleavesthepelvisthroughthegreatersciaHc
foramen,inferiortothepiriformisandsuperficialtothesciaHcnerve,
accompanyingtheinferiorglutealartery.
THECOCCYGEALPLEXUS
NERVES
Thecoccygealplexusisasmallnetworkofnervefibersformedbythe
anteriorramiofS4andS5andthecoccygealnerves.
Thecoccygealplexusliesonthepelvicsurfaceofthecoccygeusand
suppliesthismuscle,partofthelevatorani,and
thesacrococcygealjoint.
THEPELVICAUTONOMICNERVES
NERVES
Theautonomicsupplytotheabdominalandpelvicvisceraisvia:
•  theabdominopelvicpartofthesympatheHcchainandthegreater,
lesserandleastsplanchnicnerves(sympatheHc),and
•  thevagusandpelvicparasympatheHcnerves(parasympatheHc).
Autonomicnervesenterthepelviccavityviafourroutes:
•  sacralsympathe9ctrunks:primarilyprovidesympatheHc
innervaHontothelowerlimbs.
•  peri-arterialplexuses:postsynapHc,sympatheHc,vasomotorfibers
tosuperiorrectal,ovarian,andinternaliliacarteriesandtheir
derivaHvebranches.
•  hypogastricplexuses:mostimportantroutebywhichsympatheHc
fibersareconveyedtothepelvicviscera.
•  pelvicsplanchnicnerves:pathwayforparasympatheHcinnervaHon
ofpelvicvisceraanddescendingandsigmoidcolon.
THESYMPATHETICINNERVATION
NERVES
ThecellbodiesofneuronesofthesympatheHcsupplyoftheabdomen
andpelvislieintheintermediolateralgreymaReroftheT1toT12and
firsttwolumbar(L1-L2)spinalsegments.
Theseneuronesgiverisetomyelinatedaxonswhichtravelinthe
ventralramusofthespinalnerveofthesamelevel,leavingitviathe
whiteramuscommunicanstoenterathoracicorlumbarparavertebral
ganglion.
Thesegiverisetothe:
•  greater,
•  lesser,
•  leastsplanchnic
nerves,
•  lumbar,
•  sacralsplanchnic
nerves.
THEPELVICAUTONOMICNERVES
NERVES
Thesacralsympathe9ctrunksaretheinferiorconHnuaHonofthe
lumbarsympatheHctrunks.
Thesacralsympathe9ctrunksdescendposteriortotherectuminthe
extraperitonealconnecHveHssueandsendcommunicaHngbranches
(grayramicommunicantes)toeachoftheanteriorramiofthesacral
andcoccygealnerves.
THEPELVICAUTONOMICNERVES
NERVES
TheprimaryfuncHonofthesacralsympatheHctrunksistoprovide
postsynapHcfiberstothesacralplexusforsympatheHcinnervaHonof
thelowerlimb.
Theperi-arterialplexusesoftheovarian,superiorrectal,andinternal
iliacarteriesareminorroutesbywhichsympatheHc
fibersenterthepelvis.
Thehypogastricplexuses(superiorandinferior)arenetworks
ofsympatheHcandvisceralafferentnervefibers.
ThemainpartofthesuperiorhypogastricplexusisaprolongaHonof
theintermesentericplexus,whichliesinferiortothebifurcaHonofthe
aorta.
Thesuperiorhypogastricplexusentersthepelvis,dividingintoright
andleKhypogastricnerves,whichdescendontheanteriorsurfaceof
thesacrum.
THEPELVICAUTONOMICNERVES
NERVES
Thesenervesdescendlateraltotherectumandthenspreadina
fan-likefashionastheymergewiththepelvicsplanchnicnerves
toformtherightandleKinferiorhypogastricplexuses.
TheinferiorhypogastricplexusesthuscontainbothsympatheHcand
parasympatheHcfibersaswellasvisceralafferentfibers.
Pelvicsplanchnicnervesariseinthepelvisfromtheanteriorramiof
spinalnervesS2–S4ofthesacralplexus
ThepelvicsplanchicnervesconveypresynapHcparasympatheHc
fibersderivedfromtheS2–S4spinalcordsegmentsandvisceral
afferentfibersfromcellbodiesinthespinalgangliaofthe
correspondingspinalnerves.
THEPELVICAUTONOMICNERVES
Thehypogastric/pelvicsystemofplexuses,receiving
•  sympatheHcfibersvialumbarsplanchnicnervesand
•  parasympatheHcfibersviapelvicsplanchnicnerves,
innervatethepelvicviscera.
NERVES