The pancreas develops from two outpouchings of the duodenum during weeks 4-7 of gestation. It has both exocrine and endocrine functions. The exocrine pancreas produces enzymes that are released into the small intestine via a duct system to aid digestion. The endocrine pancreas is made up of clusters of cells called islets of Langerhans that secrete hormones like insulin and glucagon directly into the bloodstream. The pancreas is located in the retroperitoneal space behind the stomach and has a head, neck, body and tail. It receives blood supply from several arteries and drains into veins that empty into the portal vein. Developmental anomalies can occur if the dorsal and ventral ducts

1. THE PANCREAS
1

2. 2

3. 3

4. DEFINITION
• The pancreas (pan= all , kreas = flesh) is a
4
gland that
endocrine.
is partly exocrine and partly
The exocrine part secretes the
digestive pancreatic juice, and the endocrine
part secretes hormones, eg. Insulin.
• It is soft, lobulated and elongated organ.

5. LOCATION
• The
more
pancreas
or
lies
less
transversely across the
posterior abdominal
wall, at the level of
first and second
lumbar vertebrae.
5

6. Embryology :
Development of the
Pancreas

7. History of
Pancreas
• The first description of the pancreas was made by the Greek physician Herophilos
at around 300 bc.
• In the late first century ad, Greek physician, Rufus of Ephesus, named the organ
the “pancreas.” The term literally means “all flesh .
• “Kalikreas,” meaning “beautiful flesh,” given by Galen.
• In 1642, Wirsung characterized the pancreatic ducts of humans.
• In 1664, de Graaf discovered pancreatic secretions from the pancreatic fistula of
dogs.
• The histologic structure of the pancreas was first described in 1869 by
Langerhans.
• In 1923:Canadians Banting,Charles Best and Macleod were awarded the Prize for
successfully purifying insulin .

8. Development of
Pancreas
Source: Gorelick F, Pandol, SJ, Topazian M. Pancreatic physiology, pathophysiology, acute and chronic pancreatitis. Gastrointestinal Teaching Project, American Gastroenterologic Association. 2003.
The pancreas develops from the two buds
Ventral bud: Arises from the hepatic
diverticulum and gives the lower part of the
head and uncinated process.
Dorsal bud: Arises from the dorsal aspect of the
duodenum and gives the upper part of the head
,neck , body & tail.
Initially the dorsal pancreas grows on the dorsal side of the duodenum into the
mesoduodenum. Somewhat later the ventral pancreas appears as an evagination of the bile
duct. Source: http://www.embryology.ch(universities of Fribourg, Lausanne and Bern)
4 to 7 weeks : reference Sleisenger 10th ed.

9. Development of
pancreatic ducts
• The main pancreatic duct(duct of wirsung): from the duct of ventral
pancreas (proximally), distal part of the duct of dorsal pancreas
(distally).
• The accessory pancreatic duct(duct of Santorini): from the proximal
part of the duct of the dorsal pancreas.
Development of pancreatic acini and islets
Side branches extend from the ducts to the surrounding mesoderm.
Some of them become canalized pancreatic acini.
Others separate & not canalized Islets of Langerhans.
The pancreatic connective tissue stroma and interlobar septa: from the splanchnic
mesoderm.

10. Summary: Development
of PancreasTwo outpouchings of the endodermal
lining of the duodenum
Dorsal Bud
• lower part of the head
• uncinated process
• upper part of the head
• neck
• body & tail
• Week 7 to 20 - pancreatic hormones secretion increases, small amount maternal insulin
• Week 10 - glucagon (alpha) differentiate first, somatostatin (delta), insulin (beta) cells differentiate, insulin
secretion begins
• Week 15 - glucagon detectable in fetal plasma
Ventral Bud

11. SIZE AND SHAPE
It is J – shaped or retort shaped, set obliquely.
The bowl of the retort represents its head , and
the stem of the retort , its neck , body and tail.
It is about 15-20 cm long
2.5-3.8 cm broad and 1.2-1.8 cm thick and
weighs about 90 g
11

12. DIVISION
• The pancreas is divided( from right to left )
into the head , the neck, the body and tail.
• The head is enlarged and lies within the
concavity of the duodenum.
• The tail reaches the hilum of the spleen.
• The entire organ lies posterior to the stomach
separated from it by the lesser sac.
12

13. 13

14. 14

15. Head of thepancreas
• Head is the enlarged flattened right end of the
pancreas, situated within the curve of
duodenum.
• The head has three borders : superior, inferior
and right lateral.
• It has two surfaces: anterior and posterior
• It has one process called the uncinate process,
which projects from the lower and left part of
the head towards left.
15

16. Threeborders
The superior border is overlapped by the first part
of the duodenum and is related to the superior
pancreaticoduodenal artery.
The inferior border is related to the third part of
the duodenum and to the inferior
pancreaticoduodenal artery.
The right lateral border is related to the second
part of the duodenum, the terminal part of the bile
duct and the anastomosis between the two
pancreaticoduodenal arteries.
16
Head of the pancreas

17. 17

18. 18

19. 19
TWO SURFACES
• The anterior surface is related , from above
downwards to
• 1.the gastroduodenal artery
• 2.the tranverse colon,
• 3.the jejunum which separated from it by
peritonium.
Head of the pancreas

20. • The posterior surface is related to
• 1. the inferior vena cava.
• 2.the terminal parts of the renal vein
• 3.the right crus of the diaphragm
• 4.the bile duct
20
Head of the pancreas

21. Uncinate pancreas
• It is related
anteriorly to the
superior mesenteric
vessels and
posteriorly to the
aorta.
Head of the pancreas
21

22. Neck of thepancreas
• This is the slightly constricted part of the
pancreas between its head and body.
• It is directed forwards, upwards and to the left.
• It has two surfaces, anterior and posterior.
22

23. 23
Body of the pancreas
• The body of the pancreas is elongated.
• It extends from its neck to the tail.
• It passes towards the left with a slight upward
and backward inclination.
• It has 3 borders, 3 surfaces

24. 24
Three borders
The anterior border provides attachment to the
root of the transverse mesocolon.
The superior border is related to coeliac trunk
over the tuber omentale, the hepatic artery to
the right ,and the splenic artery to the left.
The inferior border is related to the superior
mesenteric vessels at its right end.
Body of the pancreas

25. 25
• Three surfaces
The anterior surface is concave and is directed forwards
and upwards. It is covered by peritonium, and is related
to the lesser sac and to the stomach
The posterior surface is devoid of peritonium, and is
related to
-aorta with the origin of the superior mesenteric artery,
-the left crus of the diaphragm
-the left suprarenal gland
The left kidney
Body of the pancreas

26. 26

27. • The inferior surface
is covered by
peritonium, and is
related to the
duodenojejunal
flexure, coils of
jejunum and left colic
flexure.
Body of the pancreas
27

28. TAIL OF THE PANCREAS
• This is the narrow
left end of the
pancreas .
lienorenal ligament
• It lies in the
together with the
splenic vessels.
• It comes into contact
with the lower part
of the gastric surface
of the spleen.
28

29. 29

30. 30
Ducts of the pancreas
• The exocrine pancreas is drained by two ducts,
• 1.The main pancreatic duct (duct of
wirsung)
• 2. the accessory pancreatic duct( duct of
santorini)

31. 31
• 1.The main pancreatic duct (duct of
wirsung)
• It lies near the posterior surface of the pancreas
and is recognised easily by its white colour.
• With in the head of the pancreas the pancreatic
duct is related to the bile duct which lies on its
right side. The two ducts enter the wall of the
second part of the duodenum , and join to form
the hepatopancreatic ampulla of vater .
Ducts of the pancreas

32. 32
• 2. the accessory pancreatic duct( duct of
santorini)
• It begins in the lower Part of the head , crosses
the front of the main duct with which it
communicates an opens into the duodenum at
the minor duodenal papilla.
Ducts of the pancreas

33. • - pancreatic branches of the splenicartery
• -the superior pancreaticoduiodenalartery
• -the inferior pancreaticoduodenalartery.
33
Arterial Supply ofPancreas

34. 34

35. Venous Drainage ofPancreas
• Vein drain into splenic, superior mesenteric
and portal veins
35

36. 36
Lymphaticdrainage
• Rich periacinar network that drain into 5 nodal
groups
– Superior nodes
– Anterior nodes
– Inferior nodes
– Posterior PD nodes
– Splenic nodes

37. 37

38. 38
THE PANCREAS IS BOTHAN
EXOCRINE AND ENDOCRINE
GLAND.

39. 39
THE EXOCRINE PANCREAS
• This consists of a large number of lobules made
up of small acini, the walls of which consist of
secretory cells.
• Each lobule is drained by a tiny duct and these
unite eventually to form the pancreatic duct,
which extends the whole length of the gland and
opens into the duodenum.
• The function of the exocrine pancreas is to
produce pancreatic juice containing enzymes that
digest carbohydrates , proteins and fats.

40. 40
• As in the alimentary tract, parasympathetic
stimulation increases the secretion of
pancreatic juice and sympathetic stimulation
depress it.
THE EXOCRINE PANCREAS

41. The endocrine pancreas
• Distributed throughout the gland are groups of
specialised cells called the pancreatic islets
(islets of langerhans).
• The islets have no ducts so the hormones
diffuse directly into the blood.
• The endocrine pancreas secretes the hormones
insulin and glucagon, which are principally
concerned with control of blood glucose
levels.
41

42. 42
Production of Pancreatic Hormones byThree CellTypes
 Alpha cells produce glucagon.
 Beta cells produce insulin.
 Delta cells produce somatostatin.

43. Microscopic structure.

45. Microscopic structure continued ….
The pancreas has a thin cover of loose
connective tissue from which septa pass into
the gland, subdividing it into many small
lobules.
Each lobule is again composed of several
rounded or tubular groups of pancreatic
cells called acini.
Among the acini are the scattered the islets
of langerhans.
The acini cells form the parenchyma of the

46. Exocrine Pancreas
It consist of acini,which are of serous type.
The acini are pear-shaped or short tubular groups of
pancreatic cells at the tip of inter-lobular ducts.
The connective tissue is very little between two acini.
Each acinus consists of a group of pyramidal cells
with their apical tips towards the lumen.
The cells rest upon the basal lamina.
Each cell has a big basal spherical nucleus and one
or two nucloeli.
Half of the cell towards the lumen contains numerous
zymogen granules in the cytoplasm.
The basal zone contains endoplasmic reticulum and
elongated mitochondria.
The apical region of the cells shows irregular
microvilli.

47. In the lumen of many acini
one or more epithelial cells,
lying in contact
 The exocrine pancreas is classified as a
compound tubuloacinous gland. The cells that
synthesize and secrete digestive enzymes are
arranged in grape-like clusters called acini,
very similar to what is seen in salivary glands.
Acini
cells

48. Pancreatic Ducts:-
acinar cells ultimately are delivered into
Digestive enzymes from
the
duodenum. Secretions from acini flow out of the
pancreas through a tree-like series of ducts. Duct
cells secrete a watery, bicarbonate-rich fluid
which flush the enzymes through the ducts and
play a pivotal role in neutralizing acid within the
small intestine. Pancreatic ducts are classified
into four types which are discussed
beginning with the terminal branches
here
which
extend into acini.

49. Intercalated ducts receive
secretions from acini.
They have flattened
cuboidal epithelium that
extends up into the lumen
of the acinus to form
what are called
Intercalatted ducts

50. Intralobular
ducts have a classical cuboidal
epithelium and, as the name implies, are seen
within lobules. They receive secretions from
intercalated ducts.
Intralobular duct

51. Interlobular ducts are found between lobules,
within the connective tissue septae. They vary
considerably in size. The smaller forms have a
cuboidal epithelium, while a columnar epithelium
lines the larger ducts. Intralobular ducts transmit
secretions from intralobular ducts to the major
pancreatic duct.

52. The main pancreatic duct
received secretion from
interlobular ducts and
penetrates through the wall
of the duodenum. In some
species, including man, the
pancreatic duct joins the

53. The endocrine portion of the pancreas takes the
form of many small clusters of cells called islets of
Langerhans or, more simply, islets. Humans have
roughly one million islets
In standard histological sections of the pancreas,
islets are seen as relatively pale-staining groups of
cells embedded in a sea of darker-staining
exocrine tissue. The image to the right shows
three islets in the pancreas of a horse.

54. Pancreatic islets house three major cell types,
each of which produces a different endocrine
product:
Alpha cells (A cells) secrete the hormone
glucagon.
Beta cells (B cells) produce insulin and are the
most abundant of the islet cells.
Delta cells (D cells) secrete the hormone
somatostatin, which is also produced by a
number of other endocrine cells in the body

55. Developmental
anomalies
• Variations of the Pancreatic Duct
• Developmental Anomalies of the Pancreas

56. Pancreatic
divisum
• Itis the most common congenital anomaly of the pancreas.
• PD results from a failure of the dorsal and ventral pancreatic ducts to
fuse during embryogenesis .(1)
• Thus, the bulk of pancreatic exocrine secretions must drain through
the relatively small dorsal duct of Santorini and minor papilla rather
than the ventral duct of Wirsung and the major papilla.
• It has been detected in 5% to 10% of the population in autopsy
studies and in a similar percentage of patients undergoing ERCP.(2,3,4)

57. Pancreatic
divisum
• ERCP :most definitive and reliable diagnostic method for revealing
pancreas divisum. Magnetic resonance cholangiopancreatography is a
non invasive and accurate method in the diagnosis of pancreas
divisum. The clinical relevance of pancreas divisum remains
controversial.
• Most patients with pancreas divisum are asymptomatic [1]. A relative
obstruction to pancreatic exocrine secretory flow through the duct of
Santorini and minor papilla could result in pancreatitis in a small
number of patients with pancreas divisum [2].
• Endoscopic stenting and sphincterotomy of the minor papilla might
be effective in some patients with pancreas divisum [3].

58. Annular
Pancreas
• It is a rare congenital anomaly in
which a ring of pancreatic tissue surrounds the duodenum.
• It is estimated that it occur in 1 of every 12,000–15,000 live births [1].
• The annular pancreatic tissue forms a complete (25%) or partial (75%)
ring around the descending duodenum [2,3].
• It is frequently associated with other congenital abnormalities such as
esophageal atresia, imperforate anus, congenital heart disease,
malrotation of the midgut, and Down syndrome.

59. Choledochal Cysts
• CC are a well-known anomaly that appears as dilatation of extra- or
intrabiliary trees.
• CC have been classified into five subtypes radiologically by Todani et
al. [1], which is a modification of the Alonso-Lej classification [2].
• CC, which are rare and more common in F than M, occur in approx 1 :
100,000–150,000 live births in Western countries [3].
• CC are much more prevalent in Asia than in Western countries.
Approximately 33%–50% of reported cases come from Japan, where the frequency in some studies
has approached one case per 1000 population [4].

60. Ectopic Pancreas
(pancreatic rests)
• Ectopic (heterotopic) pancreas is described as a pancreatic tissue that lacks
anatomic or vascular continuity with the normal pancreas.
• This incidence of this condition varies from 1% to 15%, depending on the
reported series.
• Ectopic pancreas is mc(70%) located at the gastric antrum, proximal
portion of the duodenum or the jejunum. Rarely it can also be found in the
ileum, colon, appendix, gallbladder or Meckel diverticulum. (1).
• This anomaly is usually asymptomatic and occurs as an incidental finding
on gastroscopy, although complications such as ulceration, bleeding,
intussusception and obstruction may develop. Rarely adenocarcinoma
occuring in the ectopic pancreatic tissue may be seen (2).

61. Ectopic Pancreas
•At barium studies: A diagnostic feature is a
central niche or umbilication, representing the
orifice of the rudimentary pancreatic duct,
containing a small collection of barium, seen in
up to 45% of cases (1)
•Surgical resection is another option, but whether
to remove ectopic pancreatic tissue that is found
incidentally remains controversial.

62. Pancreatic Agenesis and Hypoplasia of the
Dorsal Pancreas: congenital short pancreas
• Total agenesis of the pancreas is extremely rare and is incompatible
with life. Hypoplasia (partial agenesis) results from the absence of the
ventral or dorsal pancreatic anlage.
• Mutations in PDX1 have been reported in humans with pancreatic
agenesis.(1)
• Patients with dorsal pancreatic agenesis have an increased risk of DM
because most of the islet cells are located in the distal pancreas (2).

63. Accessory Pancreatic Lobe
•The accessory pancreatic lobe, an
extremely rare anomaly, is defined
as an accessory lobe of pancreatic
tissue originating from the main
pancreatic gland and containing an
aberrant duct (1).
•Recurrent acute pancreatitis is the
most common (66%) clinical
manifestation of this anomaly.
1.

64. Ansa
pancreatica
• It is a rare type of anatomical variation of the pancreatic
duct. It is a communication between the main pancreatic
duct (of Wirsung) and the accessory pancreatic duct (of
Santorini).
• The ansa pancreatica has been considered as a predisposing
factor in patients with idiopathic acute pancreatitis .(1)
• The ansa pancreatica arises as a branch duct from the
main pancreatic duct. It descends down initially, it then
ascends upward forming a loop and finally it terminates at
the minor papilla.