The brain in the central organ of the nervous system and facilitates bodily functions including senses, movement, emotions, communication, thinking, and memory. There are three parts of the brain: cerebrum, cerebellum, and brain stem. The cerebrum consists of the right and left hemisphere and is involved in functions like touch, vision, hearing, speech, reasoning, and emotions. The cerebellum regulates muscle movements and balance. The brain stem is responsible for automatic functions like breathing, body temperature, digestion, sneezing, and swelling.