Membrane Physiology (Second Edition) is a soft-cover book containing portions of Physiology of Membrane Disorders (Second Edition). The parent volume contains six major sections. This text encompasses the first three sections: The Nature of Biological Membranes, Methods for Studying Membranes, and General Problems in Membrane Biology. We hope that this smaller volume will be helpful to individuals interested in general physiology and the methods for studying general physiology. THOMAS E. ANDREOLI JOSEPH F. HOFFMAN DARRELL D. FANESTIL STANLEY G. SCHULTZ vii Preface to the Second Edition The second edition of Physiology of Membrane Disorders represents an extensive revision and a considerable expansion of the first edition. Yet the purpose of the second edition is identical to that of its predecessor, namely, to provide a rational analysis of membrane transport processes in individual membranes, cells, tissues, and organs, which in tum serves as a frame of reference for rationalizing disorders in which derangements of membrane transport processes playa cardinal role in the clinical expression of disease. As in the first edition, this book is divided into a number of individual, but closely related, sections. Part V represents a new section where the problem of transport across epithelia is treated in some detail. Finally, Part VI, which analyzes clinical derangements, has been enlarged appreciably.