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What do hormones do?

Hormone-producing glands in the bodyHormones are chemicals that travel around the bloodstream. They carry messages to different parts of your body. There are more than 50 different kinds of hormone. They are produced in small organs called glands (you can see some of them in the diagram opposite). The glands release the hormones into the bloodstream, which carries them to certain cells or organs. Hormones control activities such as growth, how fast your body uses up energy, stress, sleep and hunger.

Adrenaline flows as these men run away from the bear

How hormones work

The brain controls the release of many of the hormones in the body. When a hormone reaches a cell, it brings about a change in the way that the cell works. They may cause it to work faster or slower, or to release its products. For example, when you are frightened, a gland in the body makes a hormone called adrenaline. This makes the heart beat faster and more blood flow to the muscles, so the body is ready for action.

Growing up

There are more than 50 different kinds of hormone.

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