A . S . Iberall physiology . I . Introduction to the general notions A field and circuit thermodynamics for integrative

biological organization, ranging from molecules to humans, including clinical investigations. It is published 12 times a year investigations that illuminate normal or abnormal regulation and integration of physiological mechanisms at all levels of publishes original A field and circuit thermodynamics for integrative physiology. I. Introduction to the general notions IBERALL, A. S. A field and circuit thermodynamics for integrative physiology. 1977.-In this first of three articles on a physical basis for integrative physiology, statistical mechanical concepts are developed into a field thermodynamics. The development begins by comparing the different ways change is viewed in biology compared to physics. The Hamiltonian field concept unites the two. The requirements of a thermo-static description are introduced; then those of nonequilibrium thermody-namics are added. Conditions suitable for continuum, near-equilibrium analysis of systems are given; then the role of physical forces in organization is discussed. The development returns to statistical mechanics, and introduces conservation principles and equations of change for ensembles of interacting units. A general notion of systems and thermodynamic engines is discussed next, and a narrative account of the explanatory scope of field thermodynamics is given. Its applications to living systems are the subject of the subsequent two articles of this series. biophysics; general reductionism systems; homeokinesis; irreversible thermodynamics; THE DEVELOPMENT of integrative, quantitative physiology can be encouraged by strengthening its ties to physics. In this paper a general physical formalism is offered to the physiologist who seeks a basis for experi-men tal strategies tha t can be developed in .to an integra-tive systems outlook. Subseq uent papers (Parts II and III) &ill build from the physical notions introduced here toward a spectroscopic approach to physiological systems, and toward methods for describing cell, organ, or organismic process dynamics. The purpose of all three discussions is to show that integrative physiology can find a basis in physics that will guide experimentation. The physical basis will support a reductionistic attitude that does not lose sight of those emergent features of living systems, which are the interest of integrative physiology. Some central themes of biology are that cells are reproduced by cells, the program for reproduction is encoded genetically, and the internal environment of the cell or complex organization of cells is regulated, even though constituents turn over (17). In addition to reliable reproduction, the living organism exhibits four other essential processes: 1) sensory transduction, 2) motor actuation, 3) ingestion and energy transformation , and 4) …