EVERYDAY SCIENCE

Detailed explanation-1: -The muscles of the heart, termed the myocardium, make up the middle and thickest layer of the heart wall. This layer lies between the single-cell endocardium layer, which lines the inner chambers, and the outer epicardium, which makes up part of the pericardium that surrounds and protects the heart.

Detailed explanation-2: -Myocardium. The middle layer of the heart wall is the myocardium-the muscle tissue of the heart and the thickest layer of the heart wall. It is composed of cardiac muscle cells, or cardiomyocytes.

Detailed explanation-3: -The outer layer of the heart wall is the epicardium, the middle layer is the myocardium, and the inner layer is the endocardium.

Detailed explanation-4: -The main function of the myocardium is to facilitate the contraction and relaxation of the heart walls in order to receive and pump the blood into the systemic circulation. In addition, the myocardial cells provide a scaffold for heart chambers and conduct electrical stimuli.