ANATOMY

Detailed explanation-1: -Structure of the Heart. The walls of the heart are composed of three layers: Epicardium-the outer layer. Myocardium-the middle, muscular layer. Endocardium-the inner layer.

Detailed explanation-2: -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-3: -The outer layer, called the fibrous pericardium, secures the heart to surrounding structures like the blood vessels and the diaphragm. The inner layer, called the serous pericardium, is a double-layered section of the heart.

Detailed explanation-4: -The epicardium is an evolutionarily conserved layer of mesothelium covering the outermost cell layer of the vertebrate heart. During fetal development, the epicardium serves as a progenitor source, contributing multipotent cells that give rise to cardiac mesenchyme.

Detailed explanation-5: -The inner part of the pericardium that closely envelops the heart is, as stated, the epicardium; it is also called the visceral pericardium.