Endocardium

The endocardium is a membrane that locally lines the cavities of the heart. It forms the inner lining of the atria and ventricles. Its cells are similar both embryologically and biologically to the endothelial cells of blood vessels. The endocardium is thicker in the atria than in the ventricles. and has three layers:

• The inner or endothelial layer
• The medium or subendothelial layer
• The outer or subendocardial layer

Description

Pair of the heart with its layers, among them the endocardio

This is a thin inner lining of the heart that is made up of endothelial cells and a thin layer of loose connective tissue. A mural endocardium can be distinguished that lines the cardiac cavities (atria and ventricles), and a valvular endocardium that lines the heart valves.

A rudimentary muscle-elastic tunic and a thick subendocardial layer of loose vascularized connective tissue are added to the mural endocardium.

The heart valves are covered by the valvular endocardium. In reality, the valves are made up of two layers of endocardium and dense connective tissue that forms the skeleton of the structure and is inserted into a dense fibrous ring that gives it support.

The semilunar valves (aortic and pulmonary) have commissures and the atrioventricular valves constitute a valvular apparatus formed by the valve itself, the chordae tendineae and the papillary muscles).