A deeper dive into the ii functional components of the pancreas: exocrine and endocrine

One Organ, Two Different Functions

The pancreas is really two glands that are mixed together into one organ with ii separate functions.

Digestion (Exocrine)

Acinar cells

The bulk of the pancreas is composed of "exocrine" (exo=outward) cells that produce enzymes to help with the digestion of food.

These exocrine cells are called "acinar cells" and they produce and ship enzymes that are released into ducts and then passed into the duodenum (the first part of the small bowel), where they assist in the digestion of nutrient.

Claret Sugar (Endocrine)

Islets of Langerhans - illustration by Kyoungran Eun

The second functional component of the pancreas is the "endocrine" pancreas. The endocrine pancreas is composed of pocket-size islands of endocrine (endo=inside) cells. The islands are called the islets of Langerhans.

These endocrine cells release hormones such as insulin and glucagon into the blood stream, which maintain the proper level of sugar (glucose) in the blood. Blood sugar is used by the trunk for energy.

Why is this Important?

Agreement the two functions of the pancreas is important because:

Large tumors of the pancreas will interfere with both of these important actual functions.

  • Exocrine: when tumors cake the exocrine system, patients can develop pancreatitis and pain from the abnormal release of digestive enzymes into the substance of the pancreas instead of into the bowel, and they can develop digestive problems, such as diarrhea, from the incomplete digestion of food.
  • Endocrine: when tumors destroy the endocrine function of the pancreas, patients tin develop saccharide diabetes (abnormally high blood sugar levels).

Tumors can arise in either component, exocrine or endocrine.

  • Exocrine: the vast majority of tumors of the pancreas ascend in the exocrine part and these cancers look like pancreatic ducts under the microscope. These tumors are therefore called "ductal adenocarcinomas," or simply "adenocarcinoma," or even more only "pancreatic cancer."
  • Endocrine: less commonly, tumors ascend from the endocrine component of the pancreas and these endocrine tumors are called "pancreatic neuroendocrine tumors," or "islet cell tumors" for short.