pancreas diseases : The Endocrine Pancreas

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.

The digestive portion of the pancreas makes up more than 90 percent of its total cell mass. The digestive (or exocrine) pancreas is responsible for making digestive enzymes which are secreted into the intestines to help digest (break down) the food we eat. These enzymes digest proteins, fats, and carbohydrates into much smaller molecules so our intestines can absorb them. The picture above is an accurate representation of the pancreas which lies next to the duodenum (the first part of the small intestine right after the stomach). The actual size of the pancreas is similar to a banana which has been stepped on...it has a slight curve to it, and its about the same length, width, and thickness. The yellow "tube" running through the middle of the pancreas is called the pancreatic duct. It drains all the digestive enzymes from the pancreatic cells where they are made into the duodenum where they mix with food as it comes out of the stomach.

The Endocrine Pancreas

The emphasis of the remainder of these pages within Endocrine Web is on the Endocrine Pancreas. Approximately 5 percent of the total pancreatic mass is comprised of endocrine cells. These endocrine cells are clustered in groups within the pancreas which look like little islands of cells when examined under a microscope. This appearance led to these groups of pancreatic endocrine cells being called "Pancreatic Islets". Within pancreatic islets are cells which make specific pancreatic endocrine hormones, of which there are only a few (the most famous of course being insulin). These cells within the islets are called "Pancreatic Islet Cells".

Pancreatic islets are scattered throughout the pancreas. Like all endocrine glands, they secrete their hormones into the bloodstream and not into tubes or ducts like the digestive pancreas. Because of this need to secrete their hormones into the blood stream, pancreatic islets are surrounded by small blood vessels. This relationship is shown in the picture of a pancreatic islet where islet cells are secreting their hormones into nearby blood vessels. Remember, the purpose of endocrine cells is to make hormones which are secreted into the blood stream where they gain access to other cells very far away with the goal of making those cells respond in a specific fashion.

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