What term describes a stable internal environment maintained by the body?

The term that describes a stable internal environment maintained by the body is homeostasis. Homeostasis refers to the processes and mechanisms that the body employs to regulate its internal conditions, such as temperature, pH, hydration, and electrolyte balance, despite changes in the external environment. This dynamic equilibrium is crucial for sustaining life, allowing organisms to function optimally.

In understanding the other terms, metabolism refers to the biochemical processes that occur within a living organism to maintain life, including the conversion of food to energy. Homeodynamics relates to the concept of change within the body's systems, focusing more on the stability of systems under changing conditions rather than a stable state itself. Equilibrium generally describes a state of balance but may not encompass the active and responsive nature of the regulatory mechanisms that homeostasis entails.

Thus, homeostasis is the most appropriate term for describing the body's ability to maintain a stable internal environment crucial for health and proper physiological function.