The pancreas

The pancreas ANATOMY & PHYSIOLOGY

1. THE PANCREAS BRISSO ARACKAL BRISSO ARACKAL 1

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

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

6. 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 BRISSO ARACKAL 6

7. 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. BRISSO ARACKAL 7

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10. Head of the pancreas 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. BRISSO ARACKAL 10

11. Three boarders 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. Head of the pancreas BRISSO ARACKAL 11

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14. 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 BRISSO ARACKAL 14

15. 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 Head of the pancreas BRISSO ARACKAL 15

16. Uncinate pancreas It is related anteriorly to the superior mesenteric vessels and posteriorly to the aorta. Head of the pancreas BRISSO ARACKAL 16

17. Neck of the pancreas 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. BRISSO ARACKAL 17

18. 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 BRISSO ARACKAL 18

19. 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 BRISSO ARACKAL 19

20. 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 BRISSO ARACKAL 20

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22. 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 BRISSO ARACKAL 22

23. TAIL OF THE PANCREAS This is the narrow left end of the pancreas . It lies in the lienorenal ligament together with the splenic vessels. It comes into contact with the lower part of the gastric surface of the spleen. BRISSO ARACKAL 23

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25. 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 ) BRISSO ARACKAL 25

26. 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 BRISSO ARACKAL 26

27. 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 BRISSO ARACKAL 27

28. - pancreatic branches of the splenic artery -the superior pancreaticoduiodenal artery -the inferior pancreaticoduodenal artery. Arterial Supply of Pancreas BRISSO ARACKAL 28

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30. Venous Drainage of Pancreas Vein drain into splenic , superior mesenteric and portal veins BRISSO ARACKAL 30

31. Lymphatic drainage Rich periacinar network that drain into 5 nodal groups Superior nodes Anterior nodes Inferior nodes Posterior PD nodes Splenic nodes BRISSO ARACKAL 31

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33. THE PANCREAS IS BOTH AN EXOCRINE AND ENDOCRINE GLAND. BRISSO ARACKAL 33

34. 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. BRISSO ARACKAL 34

35. As in the alimentary tract, parasympathetic stimulation increases the secretion of pancreatic juice and sympathetic stimulation depress it. THE EXOCRINE PANCREAS BRISSO ARACKAL 35

36. 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. BRISSO ARACKAL 36

37. Production of Pancreatic Hormones by Three Cell Types Alpha cells produce glucagon. Beta cells produce insulin. Delta cells produce somatostatin. BRISSO ARACKAL 37

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