Bitesize has changed! We're updating subjects as fast as we can. Visit our new site to find Bitesize guides and clips - and tell us what you think!

Home > Science > AQA Triple Science Topics > Homeostasis > Blood Sugar Control


Blood Sugar Control


The concentration of glucose in our blood is important and must be carefully regulated. This is done by the pancreas, which releases hormones that regulate the usage and storage of glucose by cells. Type 1 diabetics are unable to make sufficient quantities of one of these hormones – insulin - and must therefore control their blood sugar levels by injecting insulin, as well as by carefully controlling their diet and exercise levels.

Controlling rising blood sugar

It is important that blood glucose [glucose: A simple sugar made by the body from food, which is used by cells to make energy in respiration. level is kept within a narrow range due to its importance as an energy source for respiration [respiration: Chemical change that takes place inside living cells, which uses glucose and oxygen to produce the energy organisms need to live. Carbon dioxide is a by-product of respiration. - but also because of the effects it could have in causing the movement of water into and out of cells by osmosis  [osmosis: The net movement of water molecules across a partially-permeable membrane from a region of low solute concentration to a region of high solute concentration.

Having eaten a meal containing sugars or starch [starch: A type of carbohydrate. Plants can turn the glucose produced in photosynthesis into starch for storage, and turn it back into glucose when it is needed for respiration. (eg sweets, potatoes, bread, rice or pasta), the starch and large sugars are digested down into glucose and absorbed across the small intestine wall into the bloodstream. This triggers a rise in blood glucose concentration.

The pancreas [pancreas: large gland located in the abdomen near the stomach which produces digestive enzymes and the hormone insulin monitors and controls the concentration of glucose in the blood. In response to an increase in blood glucose level above the normal level, the pancreas produces a hormone [hormone: Chemical messengers produced in cells or glands and carried by the blood to specific organs in the body. called insulin which is released into the bloodstream.

Insulin causes glucose to move from the blood into cells, where it is either used for respiration or stored in liver and muscle cells as glycogen. [glycogen: The storage form of glucose in animal cells. The effect of this is to lower the blood glucose concentration back to normal.

The animation below shows how this works.

In order to see this content you need to have both Javascript enabled and Flash installed.



boy smiling wearing headphones

Science Audio Bites

Put down that pen and listen to some Science audio.

More audio


Mia Cadaver illustration

Mia Cadaver's Tombstone Timeout

Revision topics from beyond the grave!

More games

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.