Small structure in brain above the roof of the mouth Stimulate one area you go into a rage. Stimulate an area just a few neurons over and you want to have sex. Hypothalamus: A small, essential region responsible for maintaining homeostasis by regulating various physiological processes, such as body temperature, hunger, thirst, and circadian rhythms. It also plays a role in controlling the release of hormones through its connection to the pituitary gland.