Brain glucose level, blood oxygen level, and other parameters. These hypothalamic nuclei send output signals to motor areas that can generate actions to rectify deficiencies. Some of the outputs also go to the pituitary gland, a tiny gland attached to the brain directly underneath the hypothalamus. The pituitary gland secretes hormones into the bloodstream, where they circulate throughout the body and induce changes in cellular activity. The individual animals need to express survival-promoting behaviors, such as seeking food, water, shelter, and a mate. The motivational system in the brain monitors the current state of satisfaction of these goals, and activates behaviors
Evolution of the brain and higher fitness that humans possess in relation to other primates. This comparative advantage is coupled with a larger brain size which ultimately allows the human mind to have a higher cognitive awareness. The evolutionary history of the human brain shows primarily a gradually bigger brain relative to body size during the evolutionary path from early primates to hominids and finally to "Homo sapiens". Human brain size has been trending upwards since 2 million years ago, with a 3 factor increase. Early australopithecine brains were little larger than chimpanzee brains. The increase has been seen as larger human brain volume