A fish -shaped graysh-pink nodular gland that stretches transversely across the posterior abdominal wall in the epigastric region that secretes various subtances such as digestives fluid,insulin and glucagon.
The pancreas is an elongated, about 15cm long. The right side of the organ (called the head) is the widest part of the organ and lies in the curve of the duodenum (the first section of the small intestine). The tapered left side extends slightly upward (called the body of the pancreas) and ends near the spleen (called the tail).

The pancreas is made up of two types of tissue:

Exocrine tissue
The exocrine tissue secretes digestive enzymes. These enzymes are secreted into a network of ducts that join the main pancreatic duct, which runs the length of the pancreas Cluster of cells(acini) which secrete digestive enzymes into the duodenum via the pancreatic duct which unites to the common bile duct Liver,biliary system and exocrine they secrete enzymes which help the3 major types of food : fat,protein and carbohodrates. to be digested and store in the liver(Food is stored in the liver in simple form to be used as second fuel:

Fat stored-->fatty acid

protein stored -->Amino acid

CHO stored -->Glycogen Liver and Pancreatic Enzymes Liver secretes : bile and bile salts --> fat digestion Pancreas secretes

Amylase -->CHO digestion

Lipase -->Fat digestion

Trypsin -->protein digestion.

Endocrine tissue
The endocrine tissue, which consists of the islets of Langerhans, secretes hormones into the bloodstream.

The human pancreas is an amazing organ with two main functions:

1. To produce pancreatic endocrine hormones (e.g., insulin & glucagon) which help regulate many aspects of our metabolism and
2. To produce pancreatic digestive enzymes.

The hormone function of the pancreas is the emphasis of this portion of Endocrine Web ~ this is referred to as the Endocrine Pancreas. Pancreatic production of insulin, somatostatin, gastrin, and glucagon plays an important role in maintaining sugar and salt balance in our bodies and therefore any problem in the production or regulation of these hormones will manifest itself with problems with blood sugar and fluid / salt imbalances.

Islet-langerhans
Irregularly shaped patches of endocrine tissue in the pancreas. The normal human pancreas has about one million of them. Beta cells, the most common islet cells, produce insulin to regulate blood glucose. (Inadequate production of insulin is characteristic of diabetes mellitus.) Alpha cells produce an opposing hormone, glucagon, which releases glucose from the liver and fatty acids from fat tissue; these favour insulin release and inhibit glucagon secretion. Delta cells produce somatostatin, which inhibits somatotropin (a major pituitary hormone), insulin, and glucagon; its metabolic role is not clear. Small numbers of another type of cell secrete pancreatic polypeptide, which slows down nutrient absorption.

Cell types :
Hormones produced in the Islets of Langerhans are secreted directly into the blood flow by (at least) four different types of cells:

• Beta cells producing Insulin and Amylin (65-80% of the islet cells)
• Alpha cells releasing Glucagon (15-20%)
• Delta cells producing Somatostatin (3-10%)
• PP cells containing Pancreatic polypeptide (1%)
• Epsilon cells containing ghrelin

Islets can influence each other through paracrine and autocrine communication, and beta-cells are coupled electrically to beta-cells (but not to other cell-types).

Paracrine feedback
The paracrine feedback system of the islets of Langerhans has the following structure:

• Insulin: Activates beta cells and inhibits alpha cells.
• Glucagon: Activates alpha which activates beta cells and delta cells.
• Somatostatin: Inhibits alpha cells and beta cells