The brain is one of the most important organs in the human body and is responsible for the main actions taken by the body. This brain is protected by the skull and is enclosed in a cranium which keeps it very safe, because it is the center of the nervous system. The structure of the human brain can be compared to other mammals, but it is three times larger and more advanced than other mammals. The brain helps the body activate muscles and secrete chemicals that allow the body to respond to external stimuli. The human brain performs executive functions as well, such as self-control, planning, reasoning, and abstract thinking, which make humans the smartest species on earth.
