What is Brain?
[[File:Blausen 0102 Brain Motor&Sensory (flipped).png|thumb|Functional areas of the cerebral cortex.]] [[Image:Brain size comparison between bird, rodent, and human with relative scale width lines.png|thumb|The comparison of brain sizes]] [[Image:Gehirn eines Rehbocks - brain of a roebuck.jpg|thumb|The brain with a hand]] 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 [[animal]]s have a brain: the exceptions are [[sponge (animal)|sponge]]s, [[cnidarian]]s, and [[lancelet]]s. [[Plant]]s and [[fungi]] do not have brains, although they do react to changes in their environment. The brain is made up of special [[cell]]s called [[Nerve|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 [[wikt:abstract|abstract]] [[thought]].<ref name=Calvin>Calvin, William H. [1996] 1998. ''How brains think: evolving intelligence, then & now''. Phoenix, London. {{ISBN|0-75380-200-7}}</ref> The brain is the main control centre of the whole body.<ref>''Encyclopedia of discovery: science''. Weldon Owen, 2001, 30{{ndash}}31. {{ISBN|1740893298}}</ref> In all animals, the brain is protected in some way. In ourselves, and all [[vertebrates]], it is protected by the [[bone]]s of the [[skull]]. == Function == The brain does the [[thinking]], learning, and feeling for the body. For humans, it is the source of [[consciousness]].<ref>We do not know for sure whether other mammals have consciousness, but it is likely from their behaviour.</ref> The brain also controls basic [[autonomic]] body actions, like [[breathing]], [[digestion]], [[heartbeat]], that happen automatically. These activities, and much else, are governed by [[unconscious]] functions of the brain and [[nervous system]]. All the information about the world ga