An action potential reaches a cardiac contractile cell, which fires, but then does not propagate the signal to to the rest of its neighboring cardiac contractile cells. What would cause the action potential to fizzle out without being propagated to the neighboring contractile cells? A Removal of the gap junctions in the intercalated discs Removal of the neuromuscular junction Removal of chloride ions from the pacemaker cells Removal of potassium ions from the pacemaker cells None of these answers are correct F Removal of calcium ions from the pacemaker cells

The heart muscle (also called the heart muscle or myocardium) is one of three types of spinal muscle tissue, the other two being skeletal muscle and smooth muscle. It is a voluntary, boring muscle that forms the major tissues of the heart wall.

The muscles of the heart muscle form the muscles around the heart. With muscle activity that causes the circulation of blood throughout the body, unlike skeletal muscle, movement is not involved in supporting health.