Diabetes, type 2 - Controlling glucose levels

Diabetes, type 2

How does my body control my blood glucose level?

Your body keeps the amount of glucose (sugar) in your blood fairly constant. If your level gets too high or too low, you can become sick. For more information, see What are the symptoms of type 2 diabetes?

And if your blood glucose level stays high for a long time, it can damage your heart,

kidney
Your kidneys are organs that filter your blood to make urine. You have two of them, on either side of your abdominal cavity, toward your back.

kidneys, eyes, feet and other parts of your body. For more on these extra problems, see What will happen to me?

In your pancreas, alpha cells make glucagon and beta cells make insulin.

Insulin and glucagon are

hormones
Hormones are chemicals that are made in certain parts of the body. They travel through the bloodstream and have an effect on other parts of the body. For example, the female sex hormone estrogen is made in a woman's ovaries. Estrogen has many different effects on a woman's body. It makes the breasts grow at puberty and helps control periods. It is also needed to get pregnant.

hormones. They control how much glucose is in your blood. These hormones are made in your pancreas, a

gland
A gland is any group of cells in the body that makes and releases something for use by another part of the body. For example, the thyroid gland makes a hormone called thyroxine. This acts on receptors within cells. By acting on the receptors it gives the cells a message to speed up their metabolism and work harder.

gland that sits just behind your stomach.

Your pancreas has small groups of cells called the islets (or islands) of Langerhans. They are named after the German doctor who discovered them. These islets have two main types of cells.

Alpha cells make glucagon.
Beta cells make insulin.

What does insulin do?

When you eat, the amount of sugar in your blood rises. This causes the beta cells in your pancreas to make more insulin.

Your pancreas makes hormones that control how much glucose is in your blood.

Almost all the cells in your body have special places on their outside where insulin sticks. These are called insulin receptors.

When insulin sticks to an insulin receptor, several things happen.

Glucose goes into your cells to give them energy.
Your

liver
Your liver is a large organ that sits on the right side of your body, just below your rib cage. It does several important things, including processing and storing nutrients from food, and breaking down chemicals, such as alcohol.

liver stops making glucose and starts storing it until your body needs more energy.
Cells in your muscles and in the fat under your skin pick up more glucose from your blood. This glucose is stored there until you need it.

These things lower the amount of glucose in your blood.

What does glucagon do?

Glucagon stops your blood glucose level from dropping too low.

When you exercise, your muscles use the glucose in your blood for energy. Your pancreas senses that you're using up your glucose supply. As your blood glucose level drops:

Your pancreas stops making insulin
Your pancreas starts making glucagon
Glucagon makes your liver, your muscles and the fat under your skin release some of the glucose stored there.

These things increase the level of glucose in your blood.

This information was last updated on May 11, 2009

This information is for educational use only, and is not a substitute for prompt professional medical advice. Readers should always consult a physician or other professional for advice and treatment.
© BMJ Publishing Group Limited 2009. All rights reserved.

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