Now the last thing I want to mention about this type of arrangement is the fact that just like certain cardiac cells in the heart are capable of displaying a type of activity known as myogenic activity, single unit smooth muscles can also exhibit the myogenic activity. And what that basically means is these cells inside the single unit smooth muscle can basically contract without the input from our nervous system. So even if we don't actually receive a signal from the nervous system, these cells can basically contract independently and that means they're myogenic. So once again the single unit smooth muscle is the most common type of arrangement of smooth muscles in the human body. Single unit smooth muscles consist of an innervating neuron that causes one or several of the smooth muscles to contract. The action potential then travels through the other smooth muscles via gap junctions between adjacent cells.