Select the correct statement about the function of myocardial cells.

Question

Quizplus · Accepted Answer

The coordinated contraction of the heart results from the fact that each cardiac muscle cell is connected by gap junctions to several neighboring cells, so that the entire heart contracts as a unit or it does not contract at all. Option A is incorrect because cardiac muscle cells are innervated by parasympathetic and sympathetic nerves, not just sympathetic nerves. Option B is incorrect because the refractory period in cardiac muscle is much longer than that in skeletal muscle. Option D is incorrect because the influx of calcium ions from extracellular sources is the initiating event in cardiac muscle contraction, not potassium ions.

Select the Correct Statement About the Function of Myocardial Cells