Accessory Digestive Organs. Liver, spleen

The documents gives an incite of the roles played by accessory digestive organs

1. Mrs. Sichela

2. LIVER
Theliveristhelargest
visceralorganinthebody
Itssituatedprimarilyinthe
righthypochondriacand
epigastricregion,extending
intothelefthypochondriac

3. The liver, gallbladder, and biliary duct system arise as a ventral
outgrowth-hepatic diverticulum-from the caudal or distal part of
the foregut early in the fourth week
The diverticulum extends into the septum transversum
The hepatic diverticulum enlarges rapidly and divides into two parts
as it grows between the layers of the ventral mesogastrium
The larger cranial part of the hepatic diverticulum is the
primordium of the liver.

4. The proliferating endodermal cells give rise to hepatocytes and to
the epithelial lining of the intrahepatic part of the biliary apparatus.
The fibrous and hematopoietic tissue and Kupffercells of the
liver are derived from mesenchyme in the septum transversum
The small caudal part of the hepatic diverticulum becomes the
gallbladder, and the stalk of the diverticulum forms the cystic duct
The stalk connecting the hepatic and cystic ducts to the duodenum
becomes the bile duct

5. FUNCTION
1.Theliverplaysanimportantroleinbileproductionandsecretion
2.Detoxification
3.Storageofcarbohydrateasglycogen
4.Proteinsynthesisfromaminoacids
5.Productionofheparinandbilepigmentsfromthebreakdownof
hemoglobin
6.Storageofcertainvitamins,iron,andcopper.
7.Itsalsoimportantinthemanufactureofredbloodcells.
8.Deaminationofaminoacids

6. Include:
a diaphragmatic
surface in the anterior,
superior, and posterior
directions; and
a visceral surface in
the inferior direction

7. The diaphragmatic surface of the liver,
which is smooth and domed, lies
against the inferior surface of the
diaphragm
Associated with it are the subphrenic
and hepatorenalrecesses:
The subphrenicrecess separates the
diaphragmatic surface of the liver from
the diaphragm
The hepatorenalrecess is between
the liver and the right kidney and right
suprarenal gland.
The subphrenicand hepatorenal
recesses are continuous anteriorly

9. Visceral surface
The visceral surface of the liver is covered with visceral peritoneum except
in the fossa for the gallbladder and at the porta hepatis
The porta hepatisserves as the point of entry into the liver for the hepatic
arteries and the portal vein, and the exit point for the hepatic ducts

10. Structures related to the liver include the following:
esophagus;
right anterior part of the stomach;
superior part of the duodenum;
lesser omentum;
gallbladder;
right colic flexure;
right transverse colon;
right kidney; and
right suprarenal gland.

12. The liver is attached to the
anterior abdominal wall by the
falciformligament
Additional folds of peritoneum
connect the liver to
the stomach (hepatogastric
ligament),
the duodenum
(hepatoduodenal ligament),
and
the diaphragm (right and left
triangular ligaments and
anterior and posterior
coronary ligaments).

14. The liver is divided into right and left
lobesby fossae for the gallbladder
and the inferior vena cava
The right lobe of liver is the largest
lobe, whereas the left lobe of liver is
smaller.
The quadrate and caudate lobes are
described as arising from the right
lobe of liver, but functionally are
distinct.
The quadrate lobe: functionally it is
related to the left lobe of the liver.
The caudate lobe:Functionally, it is
separate from the right and the left
lobes of the liver.

17. BLOOD SUPPLY
Arteries:
Thehepaticartery,abranchofthe
celiacartery,dividesintorightandleft
terminalbranchesthatentertheporta
hepatis.
Veins:
Theportalveindividesintorightand
leftterminalbranchesthatenterthe
portahepatisbehindthearteries.
Thehepaticveins(threeormore)
emergefromtheposteriorsurfaceof
theliveranddrainintotheinferior
venacava.

19. The blood vessels conveying blood to the liver are the hepatic
artery (30%) and portal vein (70%).
The hepatic artery brings oxygenated blood to the liver, and the
portal vein brings venous blood rich in the products of digestion,
which have been absorbed from the gastrointestinal tract.
The arterial and venous blood is conducted to the central veinof
each liver lobule by the liver sinusoids.
The central veins drain into the right and left hepatic veins, and
these leave the posterior surface of the liver and open directly into
the inferior vena cava.

21. VENOUS DRAINAGE
Venousblooddrainsfromthelivertotheinferior
venacavathroughtherightandlefthepaticveins
andsomesmallerveins

23. NERVESUPPLY
Nervesupplytotheliverisderivedfromthecoeliac
plexusandgastricbranchesofthevagaltrunks
LYMPHATICS
Lymphvesselsemergeeitherthroughtheportahepatis
tothenodesofthelesseromentumorpassfromthe
bareareathroughthediaphragmtothethoracicnodes
Hepaticlymphformshalfofthelymphtransmittedby
thethoracicduct

24. GALL BLADDER
Thegallbladderisapear-shapedsaclyingon
thevisceralsurfaceoftherightlobeoftheliver
inafossabetweentherightandquadrate
lobes.
Ithas:
Fundus:aroundedend,whichmayprojectfrom
theinferiorborderoftheliver
Body:amajorpartinthefossa,whichmaybe
againstthetransversecolonandthesuperior
partoftheduodenum
Aneck:anarrowpartwithmucosalfolds
formingthespiralfold.
Thegallbladderreceives,concentrates,and
storesbilefromtheliver.

25. The arterial supply to the gallbladder
is the cystic artery from the right
hepatic artery(a branch of the
hepatic artery proper).

26. CYSTOHEPATICTRIANGLE OF
CALOT
Intheanglebetweenthecommon
hepaticductandthecysticduct.
Cystohepatictriangle(ofCalot)
whichisformedby;
Superiorly-visceralsurfaceofthe
liver
Inferior-laterally-cysticduct
Medially-commonhepaticduct.

27. VENOUS DRAINAGE
Thecysticveins,drainingtheneckofthegallbladderandcysticduct:
entertheliverdirectlyordrainthroughtheportalveintotheliver,
afterjoiningtheveinsdrainingthehepaticductsandupperbile
duct.
Theveinsfromthefundusandbodyofthegallbladderpassdirectly
intothevisceralsurfaceoftheliveranddrainintothehepatic
sinusoids.

28. BILIARY SYSTEM
Asystemofvesselsandductsthatcollectanddeliverbilefromthe
liverparenchymatothesecondpartoftheduodenum.
Itisdividedintointrahepaticandextrahepaticbiliarytrees.
Theintrahepaticductsareformedfromthelargerbilecanaliculi
whichcometogethertoformsegmentalducts.
Thesefuseclosetotheportahepatisintorightandlefthepaticducts.
Theextrahepaticbiliarytreeconsistsoftherightandlefthepatic
ducts,thecommonhepaticduct,thecysticductandgallbladderand
thecommonbileduct.

30. The pancreatic duct joins the bile duct.
The joining of these two structures forms the hepatopancreatic
ampulla (ampulla of Vater),
The ampulla enters the descending (second) part of the duodenum at
the major duodenal papilla.
Surrounding the ampulla is the sphincter of ampulla (sphincter of
Oddi), which is a collection of smooth muscle.
The ampulla opens into the lumen of the duodenum by means of a small
papilla, the major duodenal papilla.
The accessory pancreatic duct empties into the duodenum just above
the major duodenal papilla at the minor duodenal papilla
Occasionally, the bile and pancreatic ducts open separately into the
duodenum.

33. PORTAL VENOUS SYSTEM
Aportalvenoussystemoccurswhenacapillarybedpoolsinto
anothercapillarybedthroughveinswithoutfirstgoingthrough
theheart.
Bothcapillarybedsandthebloodvesselsthatconnectthemare
consideredpartoftheportalvenoussystem
Portalvenoussystemsareconsideredveinsbecausetheblood
vesselsthatjointhemareeitherveinsorvenules
Examplesofsuchincludethehepaticportalsystemandhypophyseal
portalsystem

34. The portal system carries venous blood (rich in nutrients that have
been extracted from food) to the liver for processing.
The major vessel of the portal system is the portal vein.
It is the point of convergence for the venous drainage of the spleen,
pancreas, gallbladder and the abdominal part of the gastrointestinal
tract.
The portal vein is formed by the union of the splenic vein and the
superior mesenteric vein, posterior to the neck of the pancreas, at
the level of L2.

36. PORTO-SYSTEMIC ANASTOMOSIS
Undernormalconditions,theportalvenousbloodtraversestheliver
anddrainsintotheinferiorvenacavaofthesystemicvenous
circulationthroughthehepaticveins.
Thisisthedirectroute.
However,other,smallercommunicationsexistbetweentheportaland
systemicsystems,andtheybecomeimportantwhenthedirectroute
becomesblocked.

37. Gastroesophageal junction -Left gastric vein (tributaries) form a
portosystemic anastomosis with tributaries of the azygos system of
veins
Anus–superior rectal vein of the portal system anastomoses with
the middle and inferior rectal veins of the systemic venous
system
Anterior Abdominal wall around umbilicus –para-umbilical
veinsanastomoses with veins on the anterior abdominal wall

40. PANCREAS
Lieslargelyinthefloorofthelessersacintheepigastric
andlefthypochondriacregions,whereitformsamajor
portionofthestomachbed.
Itsaretroperitonealorganexceptforasmallportionof
itstail,whichliesinthelienorenalligament.

42. EMBRYOLOGY
Thepancreasdevelopsfromtwopancreaticdiverticula(buds),which
envaginatedfromtheendodermalliningoftheguttubeintheregion
ofthesecondportionoftheduodenum.
Thedorsalpancreaticbudgrowsintothedorsalmesentery.
Theventralpancreaticbudinitiallygrowsintotheventralmesentery
butsubsequentlyleavestheventralmesentery,rotatesaroundthegut
tubetoenterthedorsalmesentery.
Thetwopancreaticbudsfusetogethertoformasinglepancreasbut
retaintwoseparateductsthatentertheguttube

43. EMBRYOLOGY
Theventralbudformstheuncinateprocessandtheinferiorpartof
theheadofpancreas
Theremainingpartformsfromthedorsalbud
Themainormajorpancreaticduct(ofWirsung)isformedbythe
distalpartofthedorsalpancreaticductandtheentireventral
pancreaticduct.
Theproximalpartofthedorsalpancreaticductbecomesthe
minorpancreaticduct(ofSantorini)orobliterates

47. Thepancreasisbothanexocrineandendocrinegland.
EndocrinepartismadeupofisletsofLangerhans,
Itsecretestwomajorhormones,insulinandglucagon,
whichlowerandraisebloodsugarlevels.
Itsexocrinefunctionistoproducemostofthe
enzymesthatdigestfoodstuffsinthesmall
intestine.
Providesalkalinemediumforactivityofpancreatic
enzymes

48. Hastwoducts;
1.Mainpancreaticduct(ductofWirsung)
Beginsinthetail,runstotherightalongtheentirepancreas,and
carriespancreaticjuicecontainingenzymes.
Joinsthebileducttoformthehepatopancreaticampulla(ampullaof
Vater)beforeenteringthesecondpartoftheduodenumatthe
greaterpapilla.
2.Accessorypancreaticduct(Santorini'sduct)
Beginsinthelowerportionoftheheadanddrainsasmallportionof
theheadandbody.
Emptiesatthelesserduodenalpapillaabout2cmabovethegreater
papilla.

50. BLOOD SUPPLY AND DRAINAGE
The head is supplied by the anastomotic arcades between the superior and inferior
pancreaticoduodenal arteries.
The neck, body and tail are supplied by the splenic artery

51. Thearterialsupplytothepancreasincludesthe:
Branchesfromthegastroduodenalarteryfromthecommonhepatic
artery(abranchoftheceliactrunk):
anteriorsuperiorpancreaticoduodenalartery
posteriorsuperiorpancreaticoduodenalartery
Branchesfrominferiorpancreaticartery(abranchofthesplenic
artery);
dorsalpancreaticartery
greatpancreaticartery
Branchesfromtheinferiorpancreaticoduodenalartery(abranch
ofthesuperiormesentericartery);
anteriorinferiorpancreaticoduodenalartery
posteriorinferiorpancreaticoduodenalartery

52. NerveSupply
Sympatheticandparasympatheticnervefibresreachthepancreas
alongthearteriesfromthecoeliacandsuperiormesentericplexus
LymphDrainage
Lymphnodesofthepancreasliealongthesuperiorborderofthe
pancreas (pancreaticoduodenal nodes)and onthe
pancreaticoduodenalarteries

53. The spleen is a large hemolymphoidorgan consisting of vascular and
lymphatic tissue.
Location
The spleen is located in the left hypogastrium between the fundus of the
stomach and the diaphragm
It is found opposite the left ninth to eleventh ribs.
Ligaments
The spleen is connected to the:
greater curvature of the stomach by the gastrosplenicligament, which
contains the short gastric and gastro-omental vessels
left kidney by the splenorenalligament, which contains the splenic
vessels.
Both these ligaments are parts of the greater omentum.

55. Surfaces
diaphragmatic
visceral surfaces
Borders
superior
inferior borders
Poles
anterior (lateral)
posterior (medial) ends or poles
The spleen is surrounded by visceral peritoneum except in the area of the hilum
The splenic hilum is the entry point for the splenic vessels
The arterial supply to the spleen is the splenic artery from the celiac trunk

57. Thankyou...