Comparative physiology of the cardiac pacemaker mechanism.

Action Potentials Amphibians/physiology Animals Autonomic Nervous System/physiology Biological Transport, Active Calcium/metabolism Chick Embryo Chlorides/physiology Electric Stimulation Fishes/physiology Guinea Pigs Heart/anatomy & histology Heart Conduction System/cytology,metabolism,physiology Insecta/physiology Membrane Potentials/drug effects Mollusca/physiology Myocardium/cytology Neural Conduction Potassium/metabolism Purkinje Fibers/physiology Sinoatrial Node/cytology,metabolism,physiology Sodium/metabolism

Chlorides Sodium Potassium Calcium