2. Anatomy
• The pancreas is a retroperitoneal organ that lies in
an oblique position, sloping upward from the C-loop
of the duodenum to the splenic hilum.
• Weighs about 75 to 100gm
• Length is about 15 to 20cm
• It can be divided into Head, Uncinate process,
neck, body and tail.
• Neck lies over L1 and L2 vertebrae
3.
4. Anatomical Relations
• The neck of the pancreas lies directly over the
portal vein.
• At the inferior border of the neck, the superior
mesenteric vein joins the splenic vein and then
continues as the portal vein.
• The common bile duct runs in a deep groove on
the posterior aspect of the head.
• The body and tail lie just anterior to the splenic
artery and vein.
• The body overlies the aorta at the origin of the
superior mesenteric artery.
10. Pancreatic Duct
• Embryologically pancreas develops from a ventral
bud and a dorsal bud.
• The duct of ventral bud is called as duct of Wirsung,
which is joined by common bile duct.
• The duct of dorsal bud is called as duct of Santorini
and it drains directly into the duodenum.
• With the gut rotation, the two buds and their
respective ducts fuse. The ventral bud becomes the
inferior portion of head and uncinate process while
the dorsal bud becomes the body and tail of
pancreas.
11.
12. • Most of the pancreas drains through the duct of
Wirsung, the main pancreatic duct, and drains into
duodenum through ampulla of Vater/ major
papilla.
• In 60% of the people the duct of Santorini persists as
the lesser pancreatic duct and drains into
duodenum through lesser papilla.
• The lesser papilla is usually about 2 cms proximal to
ampulla of Vater.
• In 30% the duct of Santorini ends as blind accessory
duct and does not empty into duodenum.
13. • In 10% the duct of Wirsung and Santorini fail to fuse,
this results in majority of pancreas draining through
the duct of Santorini and lesser papilla. This is know
as pancreas divisum
• In minority of patients with pancreas divisum the
lesser papilla can be inadequate to handle the flow
of pancreatic juice resulting in outflow obstruction
leading to pancreatitis.
16. Histology
• Pancreas secretes approximately 500ml to 800ml of
pancreatic juice per day.
• Exocrine pancreas accounts for 85%
• Endocrine pancreas accounts only for 2%
• only approximately 20% of the normal pancreas is
required to prevent insufficiency.
• The acinar cells secrete amylase, proteases, and
lipases enzymes
• The centroacinar and intercalated duct cells
secrete the water and electrolytes
17.
18. Endocrine Function
Hormones
Islet Cell
Functions
Insulin
Beta Cell
Decreased gluconeogenesis,
glycogenolysis, fatty acid
breakdown, and ketogenesis
Increased glycogenesis, protein
synthesis
Glucagon
Alpha Cell
Opposite effects of insulin; increased
hepatic glycogenolysis and
gluconeogenesis
Somatostatin
Delta Cell
Inhibits GI secretion
Inhibits secretion and action of all GI
endocrine peptides
Inhibits cell growth
Pancreatic polypeptide
PP Cell
Inhibits pancreatic exocrine
secretion and secretion of insulin
Facilitates hepatic effect of insulin
19. Hormones
Islet Cell
Functions
Amylin
Beta Cell
Counterregulates insulin secretion
and function
Pancreastatin
Beta Cell
Decreases insulin and somatostatin
release
Increases glucagon release
Decreases pancreatic exocrine
secretion
Ghrelin
Epsilon Cell
Decreases insulin release and insulin
action
21. Acute Pancreatitis
• Inflammatory disease of pancreas that is associated
with little or no fibrosis of the gland.
OR
• An acute condition presenting with abdominal pain
and is usually associated with raised pancreatic
enzymes levels in the blood or urine as a result of
pancreatic inflammation.
22. Acute v/s Chronic
• Acute pancreatitis is reversible pancreatic
parenchymal injury associated with inflammation.
• Chronic pancreatitis is defined as inflammation of
the pancreas with irreversible destruction of
exocrine parenchyma, fibrosis, and, in the late
stages, the destruction of endocrine parenchyma.
24. • Mild acute pancreatitis: Interstitial oedema of the
gland and minimal organ dysfunction.
• 80% of case fall under Mild category, which has
about 1% mortality.
• Severe acute pancreatitis: pancreatic necrosis,
severe systemic inflammatory response and often
multi-organ failure.
• Mortality rate is as high as 20 to 50%
27. Biliary Tract disease
• Choledocholithiasis is the most common form of
associated biliary abnormality
• Various Theories:
o
o
o
o
Common channel hypothesis
Sphincter Incompetence
Ductal Pressure
Colocalization theory
28. Alcohol
• Pancreatitis can result with single or little alcohol
intake.
• Usually > 2 years of intake, and often history of > 10
years.
• In individuals taking 100 to 150gm/day of
alcohol, 10 to 15% can develop pancreatitis.
• It can become recurrent with continued alcohol
intake.
• Theories: secretion with blockage mechanism
• It is a metabolic toxin to pancreatic acinar cells.
• Alcohol also transiently decreases blood flow to
pancreas
29. Tumors
• Should be considered in a non alcoholic patient
with no demonstrable biliary tract disease.
• 1 to 2% of patients with acute pancreatitis have
pancreatic carcinoma
• It could be the first clinical manifestation of
periampullary tumor.
30. Iatrogenic
• Pancreatic biopsy, biliary duct exploration, distal
gastrectomy and splenectomy are associated with
acute pancreatitis.
• It is associated post op with billroth II gastrectomy
and jejunostomy.
• ERCP results in pancreatitis in 2 to 10% of cases.
32. Infections
• Mumps, coxsackievirus, and m.pneumoniae are
believed to be capable of inducing pancreatitis by
infecting acinar cells.
• Infection by ascaris lumbricoides, and clonorchis
sinensis are also implicated.
33. Hereditary
• Cationic trypsinogen/PRSS1: It is a missense
mutation, which results in
premature, intrapancreatic activation of
trypsinogen.
• It accounts for about two-thirds of cases of
hereditary pancreatitis
• A failure to express a normal trypsinogen
inhibitor, pancreatic secretory trypsin inhibitor (PSTI)
or SPINK1, is a cause of familial pancreatitis.
Editor's Notes
Due to the retroperitoneal and deep location, pain arising from pancreas is often characterized as penetrating through to the back.The neck divides the pancreas into approximately two equal halves.
Pancreatic peudocyst commonly develop in the lesser sac The posterior aspect of the stomach usually forms the anterior wall of the pseudocyst and the base of transverse colon forms the inferior wall of pseudocyst. Hence these regions can be used to drain the pseudocyst.
Common Hepatic arterygastroduodenal artery superior pancreaticoduodenal artery anterior and posterior branches Superior Mesenteric artery inferior pancreaticoduodenal arteries anterior and posterior branchesThe superior and inferior pancreaticoduodenal arteries by its branches supply the head of pancreas and the medial aspect of the C- loop of duodenum, hence it is not possible to resect the head of pancreas without resecting duodenum.Splenic artery runs along the posterior superior border of body and tail of pancreas, while the superior mesenteric artery give rise to inferior pancreatic artery which runs along the inferior border of pancreas.The splenic and inferior pancreatic arteries are joined by three branches, which run perpendicularly through the parenchyma of the body and tail of pancreas
The superior aspect of head is drained directly in to the portal vein.The posterior-inferior aspect is drained into inferior mesenteric vein.The anterior-inferior aspect is drained into right gastroepiploic vein and middle colic vein superior mesenteric vein.
Variations in portal venous anatomy. The superior mesenteric vein joins the splenic vein and then continues toward the portahepatis as the portal vein. The inferior mesenteric vein often joins the splenic vein near its junction with the portal vein, but sometimes joins the superior mesenteric vein; or the three veins merge as a trifurcation to form the portal vein.
Lymphatic drainage from pancreas is diffuse and widespread. This provides egress to tumor cells arising from the pancreas. This diffuse lymphatic drainage contributes to the fact that pancreatic cancer often presents with positive lymph nodes and a high incidence of local recurrence.
Pancreas is supplied by sympathetic and parasympathetic nervous system.Parasympathetic nervous system stimulates endocrine and exocrine secretion while sympathetic system inhibits the secretion.Somatic innervation is by celiac ganglia.
In 1/3rd of individuals the pancreatic duct and bile duct remain distinct to the end of the papilla, in another 1/3rd the two ducts fuse at the papilla and in the remaining 1/3rd a true common channel is present for a distance of several millimeters.
because alcohol causes spasm of sphincter of Oddi.Initial effect of alcohol is increase in secretion and later inhibition. This leads elevation of pancreatic enzymes that can precipitate in the ducts, leading to pressure build up. lead to pancreatic ischemic injury
It is associated post op with billroth II gastrectomy and jejunostomy as it cause increased intraduodenal pressure, which can lead to blackflow of activated enzymes in to pancreas.
Mumps, coxsackievirus, and m.pneumocniae are believed to be capable of inducing pancreatitis by infecting acinar cells. But they haven’t been isolated from diseased pancreas. Though in 30% of cases there is increase in the antibody titers of mumps and coxsackievirus. This could be a non specific reaction to pancreatitis.
