The Pancreas

The pancreas is a very complicated organ and hard to explain.  I am only going to discuss a few functions that deal with digestion and diabetes.
The pancreas has two types of glandular tissue: exocrine (digestive) and endocrine (hormone).  The Islands of Langerhans are embedded between the exocrine units.  These tiny islands contribute only about 2% of the total mass of the pancreas.  The islands, sometimes called islets, are made up, basically, of two kinds of cells: alpha cells and beta cells.  The exocrine units secrete the digestive enzymes found in pancreatic juices used in digestion.  The endocrine producing beta cells of the pancreas secrete insulin, which is a hormone.  The Islands of Langerhans produce a variety of hormones, but insulin and glycogen are the two most important; they help regulate energy in the body.
Glycogen closely resembles insulin, but it has a directly opposite effect on carbohydrate metabolism.  Glycogen is a hormone secreted by the pancreatic alpha cells that has the property of increasing concentration of glucose (sugar) in the blood.  Glycogen is stored in the liver or muscle cells.
As far as the pancreas is involved, what happens in digestion after we eat?  Pancreatic enzymes break down three elements:

• Protease (a protein-splitting enzyme) digests proteins
• Lipase (a fat-splitting enzyme) digests fat 
• Amylase (enzymes that split or hydrolyze starch) digests carbohydrates

These digestive enzymes empty into the pancreatic duct, eventually draining into the small intestines.  These digestive enzymes produced in the pancreas will not be active until they reach the intestine.  After we have eaten, the carbohydrates (sugar and starch) are broken down and digested in the stomach and intestine.  The food is absorbed through the intestine and the nutrients are taken into the bloodstream.  Your brain tells your pancreas, through many channels, about the rise in your blood sugar level and the pancreas starts to secrete insulin.  Insulin takes the glucose out of the bloodstream and puts it into the cells.  Without insulin to open the cell doors the cell does not get fed leading to many diabetic complications.  Glucose fuels the cells and allows them to do the different jobs necessary to maintain the body.  When glucose levels in the blood get back to where they should be, the pancreas stops secreting insulin.
Diabetes occurs when your body cannot produce any insulin, or does not produce enough insulin for cells to absorb the glucose needed to keep body systems working properly.  Whatever the cause may be, your body is going to try to rid itself of the unabsorbed glucose.
Our insulin sensitivity decreases with our age.  Diabetes becomes more prevalent as a person grows more sedentary and/or heavier.  We eat all the wrong things and often get very little exercise.  As we age body mass plays a very important role in becoming diabetic.  This can cause many problems, and this is why it is so important to take care of your body by maintaining a healthy diet and exercise program.