The Endocrine System
The endocrine system is used for communication throughout your body. The main communication system within your body is the nervous system. The nervous system works in a similar manner as a telephone. Messages are sent from one place to another place, much in the same way that a telephone carries a message from you to your friend.
But suppose you want to tell more than just one person. You could call all your friends on eat a time, but this would take a very long time. By the time you got the message out, it might be too late.
So how can you get a message to all your friends quickly? Suppose that you drive to your local radio station and broadcast your message. Doing this allows all your friends to hear your message at the same time.
Your endocrine system is similar to a radio broadcast. Instead of using radio waves to transmit messages,your endocrine system uses chemicals. These chemicals are called hormones. Hormones travel through the blood stream and affect the activities of the various cells within your body.
Where are these chemicals produced? Throughout your body, from your head down to your waist, there are a number of small organs called glands. These glands each produce one or more hormones. These hormones are released into the bloodstream via small tubes called ducts. Once in the bloodstream, these hormones affect every cell they come in contact with,telling them to do something.