Gastrointestinal tract second lecture theory

2nd

1. ANATOMY OF THE G.I.T.
DR. MAHMOUD MISHAAL
oTheanteriorabdominal
wall
oTheinguinalcanal

2. 1-Todescribethebloodsupply&venous
drainageoftheanteriorabdominalwall.
2-Tofollowlymphatics.
3-Tolistthemainabdominalincisions.
4-Toexploretheinguinalcanal&relateitto
regionalclinicalconditions.

3. Bloodsupplyofabdominalwall:
1-Theepigastricarteries:
A)Superiorepigastricartery:
-Oneofthe2terminaldivisionsofthe
internalthoracicartery
B)Inferiorepigastricartery:
-Abranchoftheexternaliliacartery
-Ascendsinthedirectionofthe
umbilicusintheextraperitoneal
connectivetissue
-Piercesfasciatransversalisatthe
arcuateline&entersthebackof
rectussheath
-Bothsupplymainlytherectus
muscle&sheath

4. 2-Thelumbararteries:
Fourpairs,therightonespassbehindtheIVC
Enterfibrousarchesintheoriginofpsoasmajor
Atthelateralmarginofquadratuslumborum,
theyentertheneurovascularplaneoftheAAW
The5thoneisreplacedbythelumbarbranchof
iliolumbarartery
3-Branchesfromfemoralartery

5. Veinsoftheabdominalwall:
Thesearesimilartoarterialdistribution
PortosystemicanastomosisintheAAW:
-Thereareparaumbilicalveinswhichradiate
fromtheumbilicus
-Theseveinsanastomoseononesidewith
theleftportalvein
-Ontheothersidetheyanastomosewiththe
superior&inferiorepigastricveins
-Inportalhypertensionbloodwillbe
divertedfromthelivertotheparaumbilical
veinswhichwillradiatefromtheumbilicus
givingtheshapeof(caputmedusae)

6. Lymphaticsoftheabdominalwall:
-Thereisacommunication betweenthe
lymphaticsofAAWupwardwiththechestwall&
belowwiththeexternalgenitalia
-Abovetheumbilicustheydraintotheparasternal
&anteriorgroupofaxillarynodes
-Belowtheumbilicustheydraintothesuperficial
inguinalnodes(AAWtothemedialgroup&PAW
tothelateralgroup)

7. Surgicalincisionsoftheanteriorabdominalwall:
Awell-plannedincisionshould:
1-Providereadyaccesstoanticipatedpathology
2-Provideadequateexposure
3-Allowforextensionifthescopeofoperationneedstobeexpanded
4-Minimallyinterferewithabdominalwallfunctionbypreservingimportant
abdominalstructures
5-Healwithadequatestrengthtoreducetheriskofwounddisruption&
incisionalhernia

8. 1
2
3
Main abdominal incisions:
Vertical incisions:
1-Upper midline
2-Lower midline
3-Paramedian

9. Transverse incisions:
1-Kocher (cholecystectomy)
2-Grid iron (appendicectomy)
3-Pfannenstiel (Cesarean section)
1
2
3

11. Thestoryofcreationoftheinguinalcanal:
-Testisisembryologicallyaretroperitonealorgansdevelopsintheextraperitoneal
connectivetissueoftheposteriorabdominalwall
-Inordertofunctionproperly,itneedsatemperaturelowerthanthebody’s
temperaturesoithastofinditswayoutsidetothescrotum
-Itdescendsalongtheextraperitoneallayeroftheflanktillitreachestheareaof
deepinguinalringatthe7
th
monthofIUL

12. -Thetestiswillpushthefascia
transversalisatthesiteofthe
deepring&willtakeacovering
layerfromitwhichwillbethe
futureinternalspermaticfasciaof
thecord
-Duringitspassagebelowthe
archingfibersofIO&TA,the
testiswilltakeacoverfromthese
muscles(mainlyfromIO)forming
themiddlemuscularcoatofthe
cord(cremaster)

13. -Testisreachesthesuperficialringat
the9
th
monthofIULwhereittakesa
prolongationfromEOaponeurosis
formingtheexternalspermaticfascia&
completesthecordcoverings
-Atbirth,normaltestisrestsinthe
scrotum
-Thecanalcreatedbythepassageofthe
gubernaculum&thefollowingtestis
throughtheAAWistheinguinalcanal
-Infemaleonlythegubernaculumexits
throughthispathway&whenfibrosed
thegubernaculumgivesrisetothe
roundligamentoftheuterus

14. Gubernaculum:
-Amesodermalstructurewhichleadsthetestesintheirdescent
-Itisdirectedtothelabioscrotalareawhereitends
-Itatrophiesafterbirth

15. Processusvaginalis:
-Atubularprolongationfromtheperitonealcavityaccompaniesthetestesintheir
descent
-Normallytheproximalpartofthistubewillbeclosedafterbirth&thedistalpartwill
fromthetunicavaginalistestiswhichwillprovideanatmosphereforthetestissimilar
toitsoriginalone
-Failureofclosureoftheproximalpartkeepscontinuitybetweenthescrotum&
peritonealcavity&predisposetoindirectinguinalhernia

16. Superficialinguinalring:
Atriangulargapintheaponeurosis
ofexternalobliquemuscleoverthe
medialendoftheinguinalligament
Itsbaseisformedbythepubic
crest
Edgesareprolongedoverthe
emergingcordastheexternal
spermaticfascia

17. Deepinguinalring:
Aroundedarmhole-likegapin
fasciatransvaeralis
Overliesthemidpointofinguinal
ligament
Invaginatedbythedescending
testesaroundwhichthefasciais
prolongedouttoformthe
internalspermaticfascia
Themedialboundaryofthering
isstrengthened by the
interfoveolarligament

18. Theinguinalcanal:
Anintermuscularslitwhich
extendsbetweenthesuperficial&
deepinguinalrings
About6cmlonginadult,it
overliesthemedialhalfofthe
inguinalligament
Transmitsthespermaticcordin
male&theroundligamentofthe
uterusinfemales

19. Boundariesoftheinguinalcanal:
Floor:
-Inguinalligament
-Lacunarligament(medially)
Anteriorwall:
-Externaloblique
-Astheinternalobliquearisesfromthe
lateral2\3oftheILit’lllieinfrontofthe
lateralpartofthecanal
Note:Transversusabdominiswhich
arisesfromthelateral1\2oftheILwill
notlieanteriortothecanal

20. Roof:
-FibersofIO&TAwillarchfroman
antero-lateraltoapostero-medial
positionformingtheroof&medialpart
oftheposteriorwall
Posteriorwall:
-ThearchingfibersofTA&IOwillfuse
astheconjointtendonwhichwillform
themedialpartoftheposteriorwall
-Thelateralpartofthiswallwillbe
formedbytransversalisfasciaonly

21. Conjointtendon(falxinguinalis):
-ApowerfulmusculotendinousstructureformedbythefibersofIO&TA
(mainlyTA)asthefuseposteromedialtotheinguinalcanal
-Itissuppliedbytheilioinguinalnerve
-Paralysiswillleadtodirectinguinalhernia

22. Structuresdeeptotheinguinalcanal:
1-Inferiorepigastricartery:
-Liesimmediatelymedialtothedeep
inguinalring
-Givesthecremasterica.toenterthering
2-Vasorroundligament:
Lieslateraltotheartery
3-Abnormalobturatorartery:
Arisesfromtheinferiorepigastrica.
Mayreplacetheobturatora.(30%)
4-Medialumbilicalligament:
Anobliteratedumbilicalarteryrepresented
byfibrousbandonthebackofAAW
1
2
4
3

23. Thespermaticcord:
Asthetestis&itsconnectionsintheir
wayoutthroughtheAAW,itwilltake
threeprolongationsfromthelayersof
AAW,theinnermostistakenfromfascia
transversalis,themidlefromTA&IO&
thesuperficialfromEOaponeurosis,
theseprolongationsformthecord
coverings&arefromdeeptosuperficial:
1-Internalspermaticfascia
2-Cremastericmuscle
3-Externalspermaticfascia

24. Contentsofthecord:
1-Ductusdeferens
2-Arteries:
•Testicular
•Arteryofthevas
•Cremasteric
3-Veins:pampiniformplexus
4-Nerves:
Testicularnerves(sympathetic)
Genitalbranchofgenitofemoralnerve
(forcremasterm.)
Ilioinguinaln.
5-Lymphaticsofthetestes(topara-
aorticnodes)

25. Maldescended&undescendedtestis:
oArrestofthetestisduringitscourseinthedescendingprocesswillimprison
itatanypointofthepathway
oMaldescendedtestisisfunctionless&moreliableformalignancythanthe
normallydescendedtestis

26. Indirect(oblique)inguinalhernia:
oHerniationofpartofintra-abdominalcontentsthroughapersistentprocessus
vaginalistoreachvariabledistancesintheinguinalcanal&thescrotum
oCommonerinchildren,frequentlybilateral&couldbeverylarge

27. Direct(straight)inguinalhernia:
oDuetolaxityoftheconjointtendon&increasedintra-abdominalpressure,
herniationoccursthroughtheconjointtendonforeword
oMoreinolderages,seldombilateral&rarelyattainsalargesize

28. Indirect(oblique)inguinalhernia:
Commoner inchildren,frequentlybilateral&
couldbeverylarge
Direct(straight)inguinalhernia:
oMoreinolderages,seldombilateral&rarely
attainsalargesize
Invaginationtest:
-Invaginatethescrotum&putyourfingeronthe
SIR
-Whenthepatientcoughs,animpulsewillcome
fromthesideinobliqueH
-Whenthepatientcoughs,animpulsewillcome
fromanteriorlyinstraightH
-IfyoucanblocktheSIR,nobulgingwillbeseen
duringcoughinobliqueH

29. Indirect(oblique)inguinalhernia:
Treatedbyherniotomy
Direct(straight)inguinalhernia:
Treatedbyherniorrhaphy