Conduction of the Action Potential in the Frog Ventricle

Cardiac muscle fibers are made up of individual cells joined end to end; it has been suggested that the action potential must be conducted from cell to cell by some specialized mechanism. The alternative is that the electrical resistance is low at the junctions between the cells, so that the fiber behaves like a cable. The shape and time course of the foot of the action potential and the conduction velocity in the frog ventricle fit the predictions made from the cable theory.