The brain is the master control center of the body. The brain constantly receives information from the senses about conditions both inside the body and outside it. The brain rapidly analyzes this information and then sends out messages that control body functions and actions. The brain also stores information from past experience, which makes learning and remembering possible. In addition, the brain is the source of thoughts, moods, and emotions.
In such simple animals as worms and insects, the brain consists of small groups of nerve cells. All animals with a backbone have a complicated brain made up of many parts. Animals that have an exceptionally well developed brain include apes, dolphins, and whales. Human beings have the most highly developed brain of all. It consists of billions of interconnected cells and enables people to use language, solve difficult problems, and create works of art.