Answer
The function of the heart is to pump out or expel blood. Whatever the volume of a hear chamber the blood it contains cannot be pumped out in milliseconds; complete expulsion would take about 0,5 second. In order to empty a heart chamber the heart muscle contraction must be more prolonged than the contraction of skeleton muscles.
Cardiac myocytes are striated. They are shorter than skeletal myofibers, but they are joined by intercalated discs which have gap junctions. These gap junctions enable cardiocytes to directly stimulate one another so the muscle can contract as a unit. Intercalated discs also provide mechanical connection between cardiocytes through desmosomes, so they do not pull apart during contraction.
Work Step by Step
Adherens junctions also play a role in the connection of cardiac sarcomeres.
