The thick, muscular middle layer of the heart wall that contains the atrial and ventricular muscle fibers necessary for contraction is the _____.
A) epicardium
B) pericardium
C) myocardium
D) endocardium

Question

Quizplus · Accepted Answer

The myocardium (middle layer) is a thick, muscular layer that consists of cardiac muscle fibers (cells) responsible for the pumping action of the heart.

The Thick, Muscular Middle Layer of the Heart Wall That