ANATOMY

Detailed explanation-1: -The muscle layer of the heart is termed the myocardium and is made up of cardiomyocytes. The myocardium is found in the walls of all four chambers of the heart, though it is thicker in the ventricles and thinner in the atria.

Detailed explanation-2: -Heart Wall The myocardium is the middle layer of the heart. It is the heart muscle and is the thickest layer of the heart. The epicardium is a thin layer on the surface of the heart in which the coronary arteries lie.

Detailed explanation-3: -The myocardium is mainly made up of two types of cells: cardiomyocytes and fibroblasts. Fibroblasts are distributed between cardiomyocytes, along with extracellular matrix (ECM), blood vessels, lymphatic vessels, and nerve endings.

Detailed explanation-4: -The myocardium contains a large number of mitochondria, providing energy for the heart muscle. The endocardium forms the inner lining of the heart, and the flaps which form the valves of the heart.

Detailed explanation-5: -The myocardium is the middle and thickest layer of the heart wall. (Myo-means “muscle.") Most of the heart wall is the myocardium. It also houses the cardiac electroconductive system (SA node, AV node, HIS fibers, and Purkinje fibers). PERICARDIUM: makes up the outer layers of the heart wall, enclosing the heart.