Product Description This work offers a comprehensive re-examination and elaboration of homeostasis, a guiding principle in physiology that has received surprisingly little critical evaluation. Among the key topics addressed are questions concerning the competing demands of different regulatory systems within the body and the problem of maintaining equilibrium in such circumstances. The author makes the important point that the body does not always seek constancy of its internal environment, nor does it always react in ways that prevent change. On the contrary, sometimes physiological mechanisms actively promote change. These changes in regulated levels--termed "rheostasis"--are seen as having an adaptive value beyond a simple failure of homeostasis. This book compares and categorizes examples of rheostasis for a variety of physiological variables, and presents what is known about conflicts between different regulatory systems and their role in promoting the occurrence of rheostasis. Among other topics covered are weight loss during hibernation, calcium storage and reproduction, fever, and rates of fat deposition in adults. The work of an outstanding scholar, this integrative study represents a refreshing and essential new approach to one of the basic concepts in physiological science.