PANCREAS-ACCESSORY DIGESTIVE GLAND

INTRODUCTION
STRUCTURE
DUCTS OF PANCREAS
NERVE AND MUSCLE SPHINCTER
EXOCRINE FUNCTION
ENDOCRINE FUNCTION

1. PANCREAS Faseeha.r (18pw28158) I pg. Nutrition and dietetics

2. introduction Pancreas is an elongated , accessory digestive gland.   It is a pale grey gland , weighing about 60 grams. It is about 12-15cm long , 2.5-3.8cm broad , 1.2-1.8cm thick. In humans, it is located in the abdominal cavity, behind the stomach between duodenum on the right and spleen on the left

3. Pancreas is both endocrine (ductless) and exocrine gland(duct) As an exocrine gland, it secretes digestive enzymes protease, pancreatic lipase, amylase  into a duct that empties into the small intestine. As an endocrine gland producing several important hormones, including insulin, glucagon, somatostatin,  all of which circulate in the blood

4. structure Anatomically, the pancreas is divided into the head of pancreas, the body of pancreas, and the tail of pancreas 1.HEAD Head is the enlarged flattened present in the right end of the pancreas,  situated within the curve of the duodenum. Head has 3 borders: superior, inferior and right lateral It has 2 surfaces: anterior and posterior

5. structure The anterior surface is related to 1) gastroduodenal artery        2) the transverse colon               3) the jejunum which is separated from it by  peritonium    Posterior surface is related to      1) inferior vena cava                  2) terminal parts of renal     vein           3)bile duct                  

6. structure It has one part called uncinate pancreas, which projects from the lower and left part of the head towards left. It is related anteriorly to the superior mesenteric vessels and posteriorly to the aorta. It as a hook- like extension of the head of the pancreas and highly variable in size and shape.

7. structure BODY of the pancreas is elongated It extends from the head to the tail  It passes towards the left with a slight upward and backward inclination It has 3 borders and 3 surface 1) anterior surface - covered by peritonium and related to stomach 2) posterior surface - devoid of peritonium 3) inferior surface – covered by peritonium and related to the jejunum 

8. STRUCTURE TAIL This is present in the left end of the pancreas The tip of the tail is usually blunted and linked together with the splenic vessels It comes into contact with the lower part of the gastric surface of the spleen.

9. Ducts of pancreas The exocrine pancreas is drained by 2 ducts, 1) The main pancreatic duct( duct of wirsung ) Begins in the tail of the pancreas and runs through the gland to  the head and it is closely related to the bile duct Its easily recognized by its white color The main pancreatic duct and bile duct unite to form the short, dilated hepatopancreatic ampulla(of Vater) which opens into the descending part of duodenum.

10. Ducts of pancreas 2) Accessory pancreatic duct ( duct of santorini ) It begins in the lower part of the head, crosses the front of the main duct with it communicates an open into the duodenum at the minor duodenal papilla

11. Muscle sphincter and nerves Smooth muscle sphincter control the flow of bile and pancreatic juice into the duodenum 1) sphincter of pancreatic duct 2) sphincter of bile duct 3) sphincter of hepatopancreatic ( sphincter of Oddi ) Nerves- derived from Vagus and abdominopelvic splanchnic nerves

12. structure Blood supply- the abdominal aorta and inferior vena cava lie behind the gland and supply blood ARTERY- head of the pancreas supplied by  1) superior pancreatic – duodenal artery 2)inferior pancreatic – duodenal artery Neck , body and tail is supplied by – branches of splenic artery VEINS- Pancreatic veins drains in the portal vein and superior mesentric vein

13. functions The pancreas has two main functions. The exocrine cells produce digestive enzymes to assist in digestion and the endocrine cells produce hormones to control metabolism.   1) EXOCRINE FUNCTION The pancreas contains exocrine glands made of acini cells that produce enzymes important to digestion. Pancreatic proteases (trypsin and chymotrypsin) - digest proteins into smaller amino acid subunits. Pancreatic amylase - aids in the digestion of carbohydrates.                                 Pancreatic lipase - aids in fat digestion.                                                                     

14. EXOCRINE FUNCTION When food enters the stomach, these pancreatic juices are released into a system of ducts that culminate in the main pancreatic duct . The pancreatic duct joins the common bile duct to form the ampulla of Vater   . The common bile duct originates in the liver and the gallbladder and produces another important digestive juice called bile . The pancreatic juices and bile that are released into the duodenum, help the body to digest fats, carbohydrates, and proteins

15. 2. ENDOCRINE FUNCTION Distributed throughout the gland are group of specialized cells called pancreatic islets ( islets of langerhans ) The endocrine cells of the pancreas produce hormones that control certain metabolic functions, including blood sugar regulation and digestion The islets have no ducts so the hormones diffuse directly into the blood

16. Endocrine function Alpha cell = produce , store and secrete glucagon.   Glucagon stimulate glycogenolysis and gluconeogenesis; increase blood glucose level low blood glucose levels stimulate its release. Beta cell = produce, store , secrete Insulin. Elevated blood glucose levels stimulate the release of insulin Insulin stimulate glycogenesis; decrease blood glucose level and Store glucose in the form of glycogen in liver and muscles Insulin function opposite to glucagon and work to maintain normal glucose level in blood. Somatostatin inhibit release of both glucagon and insulin Gastrin - stimulates  gastric acid secretion to aid digestion in the stomach