_____ is the ability of cardiac pacemaker cells to spontaneously initiate an electrical impulse without being stimulated from another source, such as a nerve.
- A skeletal muscle contracts only after it is stimulated by a nerve. 2. Heart has pacemaker cells that can generate an electrical impulse without being stimulated by a nerve. a. ability of cardiac pacemaker cells to create an electrical impulse without being stimulated from another source is called automaticity.