The pancreas is a 15-20cm long organ located in the retroperitoneum. It has a head, body, and tail. The pancreas contains exocrine tissue that produces enzymes to aid digestion and endocrine tissue clustered in islets of Langerhans that produce hormones like insulin and glucagon. The pancreas develops from dorsal and ventral buds that fuse during embryogenesis. It receives blood supply from various arteries and drains into veins like the portal vein. The pancreas secretes enzymes and bicarbonate to digest nutrients in the small intestine. Removal of the pancreas results in diabetes and digestive issues due to lack of enzymes.

1. Anatomy & Physiology
of the Pancreas
Sanjay George

2. Anatomy
Derived from ‘Pan’ – all ‘Kreas’ –
flesh
15-20cm long, 2.5 – 3.8cm
broad, 1.2 – 1.8cm thick
Weighs 80g
Situated in retroperitoneum

4. Contd..
Divided:
Head – 30%
Body and Tail – 70%
Head corresponds with the curve of duodenum
overlying the body of the 2nd lumbar vertebra and
the venacava.
Aorta and superior mesenteric vessels lie behind
the neck.
Near upper border of neck superior mesenteric
vein joins splenic vein to form portal vein.

6. Contd..
Coming of side of pancreatic head
and passing to the left and behind
superior mesenteric vein is uncinate
process.
Tip of pancreatic tail extends upto the
splenic hilum.

7. Histology
80-90% of pancreatic tissue – Exocrine acinar tissue
organised as lobules
Pancreatic duct Interlobular & Intralobular ducts
ductules acini
Main duct – Columnar cells
Ductules – Cuboidal cells
Acinar cells clumped around central lumen which
communicates with duct system.

8. Histology
Clusters of endocrine cells distributed throughout called
Islets of Langerhans
Islet:
75% - B Cells – Insulin
20% - A Cells – Glucagon
5% - D Cells – Somatostatin
Small number of pancreatic polypeptide cells
B cells form inner core surrounded by other cells.
Capillaries draining islet cells drain into portal vein.

9. Blood Supply
Arterial:
Pancreatic Branches of splenic
artery
Superior pancreaticoduodenal artery
Inferior pancreaticoduodenal artery
Venous:
Drain into splenic, superior
mesenteric and portal veins

10. Lymphatics
Head & Neck – Pancreaticoduodenal
Body & Tail - Pancreaticosplenic

11. Nerve Supply
Parasympathetic – Vagus
Sympathetic – plexuses around
its arteries

12. Embryology
Time Event
1 Day 26 Dorsal Pancreatic duct arises from dorsal side of
duodenum
2 Day 32 Ventral Bud arises from base of hepatic diverticulum
3 Day 37 Contact occurs between the 2 buds. Fusion by end of 6th
week
4 Week 6 Ventral bud produces the head and uncinate process
5 Week 6 Ducts Fuse
6 Week 6 Ventral duct and distal portion of dorsal duct form the
main duct
7 Week 6 Proximal duct forms the duct of Santorini
8 Month 3 Acini appear
9 Months 3-4 Islets of Langerhans Appear & become active

13. Embryology
Malrotation of ventral bud in 5th week –
annular pancreas.
Mode of ductule fusion in 7th week
produces various possible ductular
patterns.
Anatomy of main duodenal papilla –
ampulla of vater is also variable.

18. Physiology
In response to food – secretes digestive
enzymes in an alkaline bicarbonate rich
fluid.
Secretion enhanced by:
Secretin
Cholecystokinin
Vagal Stimulation
Within cells enzymes are in inactive form.

19. Pancreatic Secretions
 Electrolytes:
 Cations: Na+, K+, Ca2+, Mg2+, Zn2+
 Anions: HCO3-, Cl- and traces of SO42-, HPO42-
 Enymes:
 Pancreatic alpha-amylase
 Pancreatic lipase
 Pancreatic esterase
 Pancreatic pro-phospholipase A2
 Pancreatic proteolytic enymes:
 Trypsinogen
 Chymotrypsin
 Pro – carboxypeptidase A and B
 Ribonuclease
 Deoxy-ribonuclease
 Pro-elatase
 Trypsin inhibitor

20. Contd..
Hormones:
Insulin
Glucagon
Somatostatin

21. Total Removal of Pancreas
Diabetes mellitus due to pancreatic
endocrine deficiency of insulinn
Development of digestive disturbances:
Increase of faecal fats – bulky, foul
smelling, pale and greasy stools
Increased faecal nitrogen due to
incomplete proteolysis
No abnormality of carbohydrate digestion
Pancreatic insufficiency – loss of 30% of
calorific value of ingested food.