Hormone
Key Stage 4
Meaning
A hormone is a chemical messenger used to send signals around the body to target organs via the blood stream.
About Hormones
- Hormones are used in the coordination of the body.
- Hormones are secreted by endocrine glands.
- Different hormones affect the behaviour of different target organs.
- Hormones travel around the body through the blood.
- Hormones can last a long time in the blood before being removed so the behaviour of a target organ may be changed for some time.
Hormones compared to Electrical Impulses
- Hormones travel around the body in the blood stream while electrical impulses travel via the nerves.
- Hormones take longer to travel around the body than electrical impulses.
- The effect of hormones can be persistent while the elecrtrical impulses are instantaneous.