Answer: Automacity is the term used to define ability of some certain cardiac cells to depolarize without stimulation.
Step-by-step explanation:
Automacity is defined as the ability of cardiac or heart cells to spontaneously depolarize without stimulation. The heart automacity is a fundamental physiological function in higher organisms. Examples of such are sinoatrial node which consist of highly specialized cells that has ability to depolarize without stimulation. The cells have ability to discharge action potential. Membranes and sub membrane mechanisms interact to generate automacity.