Physiological principle of equilibrium or mass balance, what establishes and what is it used for?

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This video explains the principle of balance or the principle of mass or energy balance, which establishes that in an open system such as the organism, input and output (input and output) must be equated to keep the system in balance. In addition, its most common applications are described in detail. For example, this principle is very useful for teaching - learning the water and electrolyte balance of the body and the caloric balance or energy balance, but also to understand other concepts such as blood pressure or aortic pressure, and even renal clearance