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Spleen, pancreas, liver, and gallbladder
Spleen
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Ovoid, pulpy mass, usually the size and shape of a fist
Delicate, most vulnerable abdominal organ
Located in superolateral part of the left upper quadrant; has some
protection of the inferior thoracic cage
Largest lymphatic organ – lymphocyte proliferation and immune
surveillance, RBC and platelet storage and breakdown, recycling iron
and globin
Not a vital organ
Soft, vascular sinusoidal mass with a delicate fibroelastic capsule,
covered with a layer of visceral peritoneum
Splenic hilum is where splenic vasculature enter and leave
Rests on the left colic flexure, associated posteriorly with 9-11th ribs,
separated from them by the diaphragm and costodiaphragmatic
recess
Relations of the spleen
o Anterior: stomach
o Posterior: diaphragm, separating it from the pleura, lung and ribs
9-11
o Inferior: left colic flexure
o Medial: left kidney
Diaphragmatic surface is convex to fit under the diaphragm and ribs
Anterior and superior borders are sharp and often notched, with the
posterior and inferior borders rounded
When enlarged, the superior notched border may be palpable
Normally contains a large quantity of blood that is expelled periodically
into the circulation by the action of smooth muscle in its capsule and
trabeculae
Fibrous capsule is composed of dense, irregular fibroconnective tissue,
thickened at the hilum
Small fibrous bands of trabeculae internally carry blood vessels to and
from the splenic pulp
Contacts the posterior stomach and is connected to the greater
curvature by the gastrosplenic ligament, and to the kidney by the
splenorenal ligament; both ligaments attach to the hilum of the spleen
Splenic hilum contacts the tail of the pancreas and comprises left
boundary of the omental bursa

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Arterial supply
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Splenic artery is a branch of the coeliac trunk
Follows a torturous course posterior to the omental bursa, anterior to left
kidney, along superior border of the pancreas
Between the layers of the splenorenal ligament the artery divides into
five or more branches that enter the hilum
No anastomoses, thus there are vascular segments in the spleen (2-3)

Venous drainage
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Splenic vein is formed by several tributaries that emerge from the hilum
Joined by the inferior mesenteric vein and runs posterior to the body
and tail of the pancreas

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Splenic vein unites with the superior mesenteric vein to form the
hepatic portal vein

Lymphatic drainage
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Drain to the pancreaticosplenic lymph nodes then coeliac nodes

Innervation
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Derived from coeliac plexus, vasomotor activity

Medical application
Rupture of the spleen
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Close relation to ribs can be detrimental when ribs are fractured
Blunt trauma to other areas of the abdomen can increase
intraabdominal pressure and rupture the spleen, leading to
intraperitoneal haemorrhage

Splenectomy and splenomegaly
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Rupture repair is difficult so splenectomy is often the solution
Subtotal splenectomy is followed by rapid regeneration
Total splenectomy does not have serious effects, but greater
susceptibility to bacterial infection
Granulocyte leukaemia can cause splenomegaly, and can sometimes
be due to hypertension, haemolytic/granulocytic anaemias
Not normally palpable, but lower edge can be palpated if enlarged

Accessory spleens
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May develop near the hilum; relatively common and small
Need to be known if splenectomy is to occur, to ensure these are also
removed to prevent persistence of the symptoms for why the spleen is
being removed in the first place

Splenic needle biopsy and splenoportography
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Costodiaphragmic recess needs to be considered when splenic
needle biopsy or splenoportography (radiopaque material injected for
visualisation of the hepatic portal vein) performed
Material could enter the cavity causing pleuritis

Pancreas
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Elongated, accessory digestive gland
Retroperitoneal, overlies L1-2 vertebra (level of transpyloric plane)
Lies posterior to the stomach, duodenum on right and spleen on left
Transverse mesocolon attached to anterior margin
Pancreas produces
o Exocrine pancreatic juice (acinar cells), enters duodenum via
pancreatic ducts
o Endocrine insulin and glucagon (pancreatic islets), enter blood
Divided into the head, neck, body and tail

Head of the pancreas
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Expanded part of the gland that is encircled by the duodenum
o Firmly attached to the medial aspect of the descending and
horizontal parts
Uncinate process is a projection from the inferior part of the head,
extends posterior to the SMA
Rests posteriorly on IVC, right renal artery and vein and left renal vein
Bile duct lies in a groove on posterosuperior surface

Neck of the pancreas
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Short, overlies superior mesenteric vessels which form a groove
Anterior surface adjacent to the pylorus of the stomach
SMV joins the splenic artery posterior to form hepatic portal vein

Body of the pancreas
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Lies to the left of the superior mesenteric vessels, passes over aorta and
L2, posterior to omental bursa
Anterior surface covered with peritoneum, lies in floor of omental bursa
Posterior surface devoid of peritoneum and contacts the aorta, SMA,
left suprarenal gland, left kidney and renal vessels

Tail of the pancreas
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Lies anterior to the left kidney, close to the splenic hilum and left colic
flexure
Mobile, passes between layers of the splenorenal ligament with the
splenic vessels

Pancreatic ducts
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Main pancreatic duct begins in the tail and runs through the
parenchyma to the head, then becomes closely related to bile duct
Main pancreatic duct and bile duct unite to form the
hepatopancreatic ampulla, which opens into the duodenum at the
major duodenal papilla
o 25% of the time, they open up separately
Sphincter of the pancreatic duct, sphincter of the bile duct and
hepatopancreatic sphincter (around the hepatopancreatic ampulla)
are smooth muscle
o Control rate of bile and pancreatic juice emptying into the
ampulla, and prevents reflux of duodenal contents
Accessory pancreatic duct opens into the duodenum at the minor
duodenal papilla

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Arterial supply of the pancreas
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Mainly branches of the splenic artery
Pancreatic arteries form arcades with anterior and posterior
pancreaticoduodenal arteries (branches of the gastroduodenal) and
anterior and posterior inferior pancreaticoduodenal arteries (branches
of the SMA)

Venous drainage of the pancreas
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Corresponding pancreatic veins (tributaries of the splenic and superior
mesenteric parts of the hepatic portal vein)
Most empty into the splenic vein

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Lymphatic drainage of the pancreas
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Follow the blood vessels
Most drain to the pancreaticospelenic lymph nodes, and also pyloric
lymph nodes
Then to superior mesenteric, or coeliac nodes (via hepatic)

Innervation of the pancreas
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Derive from vagus (via abdominopelvic splanchnic nerves)
PNS and SNS fibres pass via coeliac plexus and superior mesenteric
plexus
Innervate blood vessels and acinar cells and islets
PNS are secretomotor

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Pancreatic secretion mainly mediated by secretin and cholycystokinin,
which are formed by the duodenal epithelial cells and proximal
intestine following stimulation of stomach acid contents

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Medical application
Blockage of hepatopancreatic ampulla and pancreatitis
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Gallstone can lodge in the ampulla, blocking both the biliary and
pancreatic duct systems
Bile may back up and enter pancreatic duct, resulting in pancreatitis
Reflux of bile can also result from spasms of the hepatopancreatic
sphincter
If the hepatopancreatic ampulla is obstructed, the weak pancreatic
duct sphincter may be unable to withstand the excessive pressure of bile
in the ampulla
An accessory pancreatic duct may compensate

Rupture of the pancreas
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Trauma can rupture the pancreas, causing tears in the duct system
Pancreatic juice may enter the parenchyma and invade adjacent
tissue; digestion of tissue is very painful

Pancreatic cancer
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Cancers of the pancreatic head account for most cases of extrahepatic
obstruction of the biliary ducts
Results in retention of bile pigment, enlargement of the gallbladder, and
obstructive jaundice
Jaundice is the yellow staining of body tissues, skin and mucous
membranes by circulating bile pigments
Ductal adenocarcinoma is the most common type
Can also cause obstruction of hepatic portal vein or IVC
Many local lymph nodes, and often metastasises to the liver early

Liver
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Largest gland in body, second largest organ (after skin)
All nutrients (apart from fat) absorbed from the GI tract are initially
conveyed to the liver via the portal venous system
Functions in metabolism, glycogen storage, bile secretion
Bile passes from liver via the right and left hepatic/biliary ducts to join as
the common hepatic duct, then unite with the cystic duct to form the
common bile duct
Bile produced continually by the liver, but between meals it
accumulates and stored in the gallbladder

Surface anatomy
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Mainly lies in the right upper quadrant of the abdomen, protected by
the thoracic cage and diaphragm
Lies deep to ribs 7-11, crosses midline
Moves with excursion of the diaphragm and located more inferiorly
when one is erect because of gravity

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Surfaces of the liver
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Convex diaphragmatic surface and flat/concave visceral surface
Sharp inferior border follows the right costal margin, inferior to the
diaphragm
Diaphragmatic surface is smooth and dome shaped, separated from
pleura, lungs and pericardium of the heart by the diaphragm
Subphrenic recesses (superior extensions of the peritoneal cavity)
between the diaphragm and anterior/superior surfaces of liver
Falciform ligament separates the subphrenic recesses into right and left
recesses
Subhepatic space between the inferior border of the liver and the
supracolic compartment of the peritoneal cavity
Hepatorenal recess is an extension of the subhepatic space in the
posterosuperior direction
o Lies between the right visceral surface of the liver and right
kidney and suprarenal gland
o Gravity dependent in supine position; fluid draining from the
omental bursa drains here, and communicates with right
subphrenic recess

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Reflections of the liver
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Diaphragmatic surface covered with visceral peritoneum, apart from
the posterior bare area (directly contacts the diaphragm)
In the bare area, the peritoneum reflects from the diaphragm as the
coronary ligament
Right triangular ligament formed from where the anterior and posterior
layer of the coronary ligament meet, enclosing the bare area
Left triangular ligament formed near the apex, from the anterior and
posterior layer of the coronary ligament
In the bare area is a groove for the vena cava
Visceral surface is covered with visceral peritoneum bar the fossa for
the gallbladder and the porta hepatis (where the vessels, nerves and
ducts enter/leave)
Visceral surface has many fissures and impressions from contact with
other organs

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Relations of the liver
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Two sagittal fissures are linked centrally by the porta hepatis to form a H
shape on the visceral surface
Right sagittal fissure formed from the fossa of the gallbladder anteriorly
and the groove for the vena cava posteriorly
Left sagittal fissure is formed by fissure of the round ligament anteriorly
and fissure for the ligamentum venosum posteriorly (remnant of foetal
ductus venosus)
Round ligament of the liver is a remnant of the umbilical vein
Lesser omentum encloses the portal triad (bile duct, hepatic artery,
hepatic portal vein) and passes from the liver to the lesser curvature of
the stomach and superior duodenum
The hepatoduodenal ligament extends between the porta hepatis and
the duodenum, enclosing the structures passing to/from the porta
hepatis
Hepatogastric ligament extends between the groove for the
ligamentum venosum and lesser curvature of the stomach
Liver is also related to
o Right side of anterior stomach (gastric and pyloric areas)
o Superior duodenum (duodenal area)
o Lesser omentum
o Gallbladder
o Right colic flexure and right transverse colon (colic area)
o Right kidney and suprarenal gland (renal and suprarenal area)

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Anatomical lobes of the liver
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Divided into two anatomical lobes plus two accessory lobes by the
peritoneal reflections and the fissures formed by the reflections and
vessels
The falciform ligament and left sagittal fissure separate right and left
lobes
On the visceral surface, the right and left sagittal fissures plus the
transverse porta hepatis define two accessory lobes – anterioinferior
quadrate lobe and posterosuperior caudate lobe
Caudate lobe has an elongated papillary process
Caudate process extends right between the IVC and porta hepatis,
connecting the caudate and right lobes

Functional subdivisions of the liver
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Functionally independent right and left lobes; more equal in size than
the anatomical lobes (right still slightly larger than left)
o Caudate lobe may also be considered independent
Each part has its own primary branch of the hepatic artery and
drained by own branches of hepatic portal vein and hepatic duct
Can be further divided into four subdivisions then to eight surgically
resectable segments (served independently by secondary/tertiary
branches of the hepatic triad)
Aside from caudate segment, liver can be subdivided into right and
left based on bifurcation of the hepatic triad
The main portal fissure is plane between the right and left lobes,
demarked by the IVC (and right sagittal fissure on the visceral surface)
Right and left livers subdivided vertically into medial and lateral
divisions by the right portal and umbilical fissures, where the right and
left hepatic veins lie; right portal fissure has no external demarcation
Each division receives a secondary branch of the triad
Transverse hepatic plane divides three of the four divisions, making six
hepatic segments, each receiving a tertiary branch of the triad
Main part of the liver thus has 7 segments (II-VII), plus caudate
(segment I); caudate supplied by triad branches from both divisions

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Blood vessels
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Dual blood supply; dominant venous source and lesser arterial
Hepatic portal vein brings ~80% of blood to the liver; supplies
parenchyma
Hepatic portal vein carries nutrients from the GI tract to the liver
sinusoids; lipids are absorbed into the lymphatic system and bypass the
liver
Hepatic arteries initially distributed to stromal structures particularly the
intrahepatic bile ducts
Hepatic portal vein formed from union of the splenic vein and superior
mesenteric; ascends as part of the portal triad in the hepatoduodenal
ligament, anterior to the IVC
Hepatic artery arises from the coeliac trunk, divides into common
hepatic and hepatic artery proper
Close to porta hepatis, the hepatic artery and hepatic porta vein
terminate by dividing into right and left branches, then further divide as
the triad to supply the different lobes
The right, intermediate and left hepatic veins drain parts of the central
segments into the central veins then to the IVC

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Lymphatic drainage
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Major lymph producing organ (25-50% entering thoracic duct comes
from liver)
Superficial lymphatics occur in the fibrous capsule of the liver, and
deep lymphatics in the connective tissue
Most lymph formed in the perisinusoidal spaces and drains into deep
lymphatics in the intralobular portal triads
Superficial lymphatics from anterior aspect drain to the hepatic lymph
nodes, then to coeliac nodes then cisterna chyli (dilated sac)

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Superficial lymphatics from posterior aspect drain to phrenic nodes or
posterior mediastinal lymph nodes; some parts also to left gastric
nodes, parasternal nodes

Innervation of the liver
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Derived from hepatic plexus
SNS fibres from coeliac plexus and PNS fibres from the vagal trunks
Role in vasoconstriction, other roles unclear

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Medical application
Subphrenic abscesses
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Peritonitis can result in formation of localised abscesses, a common site
being the subphrenic recesses/spaces
Subphrenic abscesses more common on the right side due to frequent
ruptured appendix and perforated duodenal ulcers
Subphrenic recesses are continuous with the hepatorenal recess, thus
can drain there when supine

Hepatic lobectomies and segmentectomy
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As branches of the arteries and veins don’t communicate, possible to
perform lobectomies without excessive bleeding
Can also do segmentectomies; segments vary in size and shape in
different people
Most injury is normally to the right side

Rupture of liver
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Easily injured as large, fixed position and friable
Fractured rib can puncture the liver, which can cause considerable
haemorrhage due to high vascularisation

Hepatomegaly
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As IVC and hepatic portal vein lack valves, a rise in central venous
pressure will transfer blood to the liver, causing hepatomegaly
Temporary engorgement will stretch the fibrous capsule, causing pain
around lower ribs; this plus diaphragm activity may cause runners stitch
Congestive heart failure and tumours can cause hepatomegaly
Bacterial and viral infections can cause hepatitis leading to
hepatomegaly
When enlarged the inferior edge may be palpated
Common site of metastatic carcinoma drained by the portal system of
veins from the gut, also from thorax e
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breast due to communication
between lymph nodes draining the bare area of liver and thorax

Liver cirrhosis
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Main site for detoxification of substances absorbed by GI tract;
vulnerable to cellular damage and scarring
Results in progressive destruction of hepatocytes in hepatic cirrhosis,
and replacement by fat and fibrous tissue
Alcoholic cirrhosis most common form
Firmness of the cirrhosis liver can cause portal hypertension
As liver has functional reserve, metabolic evidence of failure
appears late
Treatment may involve portosystemic or portocaval shunt,
anastomosing the portal and systemic venous systems

Biliary ducts and gallbladder
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Biliary ducts convey bile from the liver to the duodenum
Bile produced continually by the liver and stored and concentrated in
the gallbladder, which releases it intermittently when fat enters the
duodenum
Bile emulsifies fat for absorption in the small intestine
Hepatic tissue has hexagonal shaped liver lobules with central vein and
emerging sinusoids, with plates of hepatocytes
Hepatocytes secrete bile into bile canniculi, which drain into
interlobular biliary ducts then large collecting bile ducts of the hepatic
triad, which merge to form hepatic ducts
Right and left hepatic ducts drain the right and left parts of the liver
Right and left ducts unite to form the common hepatic duct after
leaving the porta hepatis
Cystic duct joins the common hepatic duct to form the bile duct

Bile duct
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Formed from union of cystic duct and common hepatic duct
Descends posterior to the superior part of the duodenum, lying in a
groove of the posterior surface of the head of the pancreas
Bile duct contacts the pancreatic duct on the left side of the
descending duodenum – unite forming the hepatopancreatic ampulla
The ampulla opens into the duodenum via major duodenal papilla
Sphincter of the bile duct constricts to prevent bile entering ampulla
and thus the duodenum; backs up into the gallbladder

Arterial supply
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Proximal part: cystic part
Middle part: right hepatic artery
Retroduodenal part: posterior superior hepatoduodenal artery and
gastroduodenal artery

Venous drainage
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Enters liver directly, with posterior superior pancreaticoduodenal vein
draining the distal part, emptying into hepatic portal vein or a tributary

Lymphatic drainage
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Pass to the cystic nodes, nodes of omental foramen and hepatic
nodes and coeliac nodes

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Gallbladder
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Lies on fossa for the gallbladder on the viscera surface of the liver
Intimate relationship with the duodenum; body lies anterior to the
superior part of the duodenum, with neck and cystic duct superior
Can hold upto 50mL bile
Peritoneum surrounds the fundus, binding the body and neck to the
liver
Hepatic surface attached to the liver via fibrous capsule of the liver
Three parts
o Fundus: projects from inferior surface of the liver
o Body: contacts visceral surface of the liver, transverse colon, and
superior duodenum
o Neck: narrow tapering end directed towards porta hepatis
Cystic duct connects neck o gallbladder to the common hepatic duct
o Spiral fold (valve) keeps cystic duct open, allowing diversion of
bile into the gallbladder when distal end of the bile duct is
closed by the sphincter of the bile duct and/or
hepatopancreatic sphincter
o Bile can pass to the duodenum as the gallbladder contracts

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Arterial supply
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Cystic artery, arising from the right hepatic artery in the cystohepatic
triangle between the common hepatic duct, cystic duct and visceral
surface of the liver

Venous drainage
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Neck of gallbladder and cystic duct: cystic veins
Fundus and body: hepatic sinusoids

Lymphatic drainage
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Cystic lymph nodes to the hepatic lymph nodes, then coeliac lymph
nodes

Innervation
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SNS and visceral afferents from coeliac plexus and PNS afferents
(vagus) and somatic afferent (phrenic nerve)
PNS stimulation contracts the gallbladder and relaxes the sphincters at
the hepatopancreatic ampulla
BUT these responses generally stimulated by cholecystokinin produced
by duodenal walls in response to arrival of fats

Medical application
Gallstones (cholelithiasis)
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Concentration of cholesterol crystals in the gallbladder, cystic duct
or bile duct
More common in females, increases with age
Must obtain size to produce mechanical injury or obstruct in order
to produce symptoms
Distal end of the hepatopancreatic ampulla is narrow and
commonest site for gallstones
Lodge in cystic duct can cause biliary colic, if it blocks the cystic
duct it can cause cholecystitis
An abnormal sacculation can form where gallstones collect at the
junction of the gallbladder and the cystic duct
o Rupture of a peptic duodenal ulcer can create a false
passage between the duodenum and the pouch, allowing
gallstones to enter the duodenum
If bile can’t leave the gallbladder, it enters the blood and causes
jaundice

Hepatic portal vein and portal-systemic anastomoses
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Hepatic portal vein is main channel of portal venous system
Forms anterior to the IVC, posterior to the neck of the pancreas, from
union of superior mesenteric and splenic veins
In 1/3 of people the inferior mesenteric also joins, but in 2/3 it joins the
splenic vein or superior mesenteric
Hepatic portal vein runs a short course, mostly within the
hepatoduodenal ligament
Divides into left and right branches as it approaches the porta hepatis
Collects blood from abdominal part of the alimentary system (including
gallbladder, pancreas and spleen); low in oxygen and rich in nutrients
Blood from splenic vein, containing products of RBC breakdown passes
to left liver
Blood from superior mesenteric, containing nutrients from the intestines,
passes mostly to right liver
Portal-systemic anastomoses formed in submucosa of the inferior
oesophagus and anal canal, and peri umbilical region and bare area
of the liver
Collateral routes allow backup in case of compromise

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Hepatic portal vein and its tributaries have no valves, so blood can flow
in reverse direction to the IVC, but can result in varices

Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition
Taken from Moore et al, Clinically Oriented Anatomy, Seventh Edition

Medical application

Portal hypertension
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Scarring and fibrosis of the liver from cirrhosis can obstruct the hepatic
portal vein
This can result in increased pressure in the veins resulting in portal
hypertension
Large volume of blood flowing from the portal system to the systemic
system at the anastomoses site can produce varicose veins, particularly
the lower oesophagus
o Can haemorrhage
Common method is to divert blood from the portal venous system to
systemic via a portosystemic shunt

Reference
1
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Clinically Oriented Anatomy
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