Brain

The brain is the part of the body which lets living beings think. It does some bodily functions, such as telling the rest of the body what to do. Almost all animals have a brain: an exception are sponges. Plants do not have brains, although they do react to changes in their environment.

The brain is made up of special cells called nerves, which are connected with each other and with other nerves in our body.

The brain gets input from sense organs, and changes behavior in response to this information. In humans, the brain also controls our use of language, and is capable of abstract thought.[1] The brain is the main control centre of the whole body.[2] 

In all animals, the brain is protected in some way. In ourselves, and all vertebrates, it is protected by the bones of the skull.

1. ↑ Calvin, William H. [1996] 1998. How brains think: evolving intelligence, then & now. Phoenix, London. ISBN 0-75380-200-7
2. ↑ Encyclopedia of discovery: science. Weldon Owen, 2001, 30–31. ISBN 1740893298