Anatomy and physiology of the pancreas

The pancreas is a flat, pear-shaped gland located behind and below the stomach. It is part of the digestive system and the endocrine system.

Structure

The pancreas is about fifteen centimetres (six inches) long. The widest section is the head, and the narrowest part is the tail. The middle section is called the body. The pancreas has a series of small tubes that drain into the pancreatic duct. The pancreatic duct joins the common bile duct and empties into the upper part of the small intestine, which is called the duodenum.

Function

The pancreas is made up of two different cell types – exocrine and endocrine. These cells have different functions.

Exocrine cells

Most of the cells in the pancreas are exocrine cells. Exocrine cells produce and release pancreatic juice. The juice travels through the pancreatic duct into the duodenum. Enzymes in the pancreatic juice help digest fat, carbohydrates and protein in food.

Endocrine cells

A small portion of the cells in the pancreas are endocrine cells. They are arranged in clusters called islets, or islets of Langerhans. The islets produce and release two hormones into the blood that help control blood sugar level:

• insulin
  • reduces the amount of sugar in the blood when the blood sugar is high
  • stimulates the liver, muscles and fatty tissues to absorb and store the extra blood glucose
• glucagon
  • increases the amount of sugar in the blood when the blood sugar is low
  • stimulates the liver and other body tissues to release stored glucose