Insulin and the pancreas

Insulin — what is it and what does it do?

Insulin is a hormone that is made in the pancreas, an organ that lies behind the stomach in the abdomen. Insulin helps to move glucose (a type of sugar) from the blood into the cells of the body so that the cells can use the glucose as an energy source — during exercise for example. Insulin also helps to change any excess glucose that the body does not immediately need into a storable form of energy (called glycogen) in the liver.

What is the pancreas and what does it do?

The pancreas is an organ found behind the stomach. It has two important functions. It helps to:

  • control blood glucose levels
  • digest food in the stomach.
Illustration showing the size and location of the pancreas behind the stomach.

The pancreas helps to control blood glucose by producing insulin. It also produces digestive juices and enzymes to break down food. Image: Shutterstock.com

The pancreas helps to control blood glucose levels by producing insulin when the amount of glucose (a type of sugar) in the blood increases — for instance after a meal. This insulin helps the glucose to move out of the blood and into the body’s cells so that the cells can use the glucose as an energy source, during exercise for example. The insulin also helps to store any excess glucose in the liver and in the fatty (adipose) tissues of the body.

Pancreatic disease (chronic pancreatitis) or damage to the pancreas, in particular to the cells in the pancreas that produce insulin, can cause diabetes. This means that the pancreas makes less insulin, resulting in higher than normal blood glucose levels.

The pancreas also produces digestive juices and enzymes to break down partially digested food in the stomach.

Insulin resistance — what is it?

Certain types of cells (e.g. those in muscle, the liver and fat) that normally use or store glucose (a type of sugar) need insulin to take up glucose from the blood stream. Insulin resistance happens when these cells or tissues don’t respond properly to the insulin made by the pancreas, meaning that glucose stays in the blood and glucose levels continue to rise.