THORAX ABDOMEN AND PELVIS

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: -The layers of the heart are as follows: Pericardium, or the layer surrounding the heart. Epicardium, the outside layer of the heart. Myocardium, the middle layer of the heart.

Detailed explanation-3: -Cardiac muscle, also called the myocardium, is one of three major categories of muscles found within the human body, along with smooth muscle and skeletal muscle. Cardiac muscle, like skeletal muscle, is made up of sarcomeres that allow for contractility.