This graduate text, suitable for students in physiology and biophysics, and medical students specializing in neurophysiology and related fields, is a comprehensive discussion of biological mass transfer and bioelectrical phenomena. Emphasis is given to the applicability of physics, physical chemistry and mathematics to the quantitative analysis of biological processes, with all the necessary mathematical grounding provided in Chapter 1. This book guides the student through four key stages of quantitative analysis, which are central to the understanding of cell membrane functions.