Intended for advanced undergraduates and beginning graduate students in biophysics, biological physics, physiology, medical physics, cell biology, and biomedical engineering who have had prior course in physics and in calculus, this text bridges the gap between introductory physics and its application to the life sciences. Among the many topics treated in this wide-ranging book are: forces in the skeletal system; fluid flow, with examples from the circulatory system; the logistic equation; scaling; transport of neutral particles by diffusion and by solvent drag; membranes and osmosis; equipartition of energy in statistical mechanics; the chemical potential and free energy; biological magnetic fieds; membranes and gated channels in membranes; nonlinear phenomena, including biological clocks and chaotic behavior; signal anaysis; detection of weak signals; radiological physics and the use of x-rays in diagnosis and therapy; magnetic resonance imaging. The text includes many problems to test the student's understanding, and chapters include useful bibliographies for further reading. Its minimal prerequisites and wide coverage make ideal for self-study, as well as a useful reference for workers in medical and biological research. The fourth edition will be updated throughout to reflect new developments; the discussion of theory will be more closely linked to experiment; a discussion of stochastic processes will be added; the discussions of anatomy and biology will be expanded.