This text, suitable for graduates and researchers in physiology and biophysics and medical students specialising in neurophysiology and related fields, provides a comprehensive discussion of biological mass transfer and bioelectrical phenomena. Emphasis has been 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. The quantitative analysis is broken into four key stages: - Formulation of a biological/biophysical model - Derivation of the associated mathematical description of the model - Solution of the mathematical expression - Interpretation of the mathematical solution to a biological explanation This book guides the student through these stages, which are central to the understanding of cell membrane functions.