Physiological balance is defined as the organism’s capacity to maintain a stable internal environment, a fundamental principle known as homeostasis. Homeostasis comprises a set of regulatory mechanisms that keep vital parameters such as temperature, pH, blood pressure, glucose levels, and oxygen concentration within a narrow range. In this process, all organs and systems work in constant interaction, primarily governed by the nervous and endocrine systems. To maintain homeostatic balance, the body employs negative feedback mechanisms. Moreover, intersystem interactions not only help preserve balance but also enable the organism to adapt to environmental stressors. For instance, the immune system modulates inflammatory responses through its interaction with the nervous system, while the relationship between the musculoskeletal and endocrine systems ensures metabolic adaptation during exercise. In conclusion, the sustainability of homeostasis is made possible by the integration of systems, dynamic feedback loops, and the coordinated operation of precise control mechanisms at the cellular level. This integrated structure supports the organism’s survival and resilience against changing environmental conditions.