Provided here is an up to date account of how high pressuresaffect cellularprocesses in microorganisms and ineukaryotic cells. Topics include membranetransport, cellactivation, the excitable properties of cells, muscularcontraction, with particular emphasis on cardiac muscle, andthe role of pressure in the physiology of cartilage in loadbearing joints. Additionally there are thorough reviews ofthe effects of pressure on fish and on the central nervoussystem of mammals, including man.