Homeostasis is a process by which the body maintains a stable internal environment within a narrow range of variation.Homeostasis (Greek for “staying the same”) is a process by which the body maintains a stable internal environment. The hypothalamus is a part of the brain that helps the body maintain homeostasis. It is located in the brain just above the brainstem and is a group of neurons that forms the primary link between the nervous system and the endocrine system. This small part of the brain is responsible for regulating many key body processes including internal body temperature, hunger, thirst, blood pressure, and daily (circadian) rhythms.