The section deals with phenomena, the essence of which is determined by the chaotic motion of a huge number of molecules, which constitute bodies of different nature. Two main methods are used to study these phenomena. One of them is the thermodynamic method; it follows from basic experimental laws called the fundamentals (laws, principles) of thermodynamics. This approach does not take into account the internal structure of a material.
Another method is molecular kinetics (statistical method), which is based on the idea of molecular structure of a substance. By taking into account a large number of molecules in a substance, it is possible to determine certain laws using the theory of probability.
The section uses both approaches to varying extents.
It is important for physicians to understand energy properties of a body, heat exchange of biological systems with the environment, clarification of physical processes taking place in biological membranes, etc.
Chapter 12
Thermodynamics
Thermodynamics is a branch of physics that considers systems (thermodynamic systems), among which energy exchange is possible, without taking into account the microscopic structure of the bodies that make up the system. We distinguish thermodynamics of equilibrium systems, or systems passing to equilibrium (classical, or equilibrium thermodynamics, which is often called simply thermodynamics), and the thermodynamics of non-equilibrium systems (non-equilibrium thermodynamics). Non-equilibrium thermodynamics is of special importance when considering biological systems.
Along with thermodynamics, problems associated with use of low temperatures and heated media for therapeutic purposes, this chapter covers issues of thermometry and calorimetry too.