Epicardium ā thin, transparent, outer layer of the heart wall (visceral pericardium) which is composed of mesothelium and delicate connective tissue that imparts a smooth, slippery texture to the outermost surface of the heart
Myocardium ā cardiac muscle tissue that makes up about 95% of the heart and is responsible for its pumping action. It is striated and involuntary.
Endocardium ā a thin layer of endothelium overlying a thin layer of connective tissue that provides a smooth lining for the heart chamber and covers the heart valves. It is continuous with the endothelial lining of large blood vessels attached to the heart and minimizes surface friction as blood passes.
Right atrium ā is about 2-3 mm thick and forms the right border of the heart which receives blood from the epicardium, superior and inferior vena cava, and coronary virus.
Left atrium ā same thickness as RA and forms most of the base of the heart. It receives blood from the lungs through four pulmonary veins.
Right ventricle ā about 4-5 mm thick and forms most of the anterior surface of the heart. Blood passes from the right ventricle through the pulmonary valve into the large artery.
Left ventricle ā is about 10-15 mm thick and forms the apex of the heart. Blood passes from the left ventricle through the aortic valve into the ascending aorta.
Structure of 3 layers of the heart
Epicardium ā thin, transparent, outer layer of the heart wall (visceral pericardium) which is composed of mesothelium and delicate connective tissue that imparts a smooth, slippery texture to the outermost surface of the heart
Myocardium ā cardiac muscle tissue that makes up about 95% of the heart and is responsible for its pumping action. It is striated and involuntary.
Endocardium ā a thin layer of endothelium overlying a thin layer of connective tissue that provides a smooth lining for the heart chamber and covers the heart valves. It is continuous with the endothelial lining of large blood vessels attached to the heart and minimizes surface friction as blood passes.
4 chambers of the heart
Right atrium ā is about 2-3 mm thick and forms the right border of the heart which receives blood from the epicardium, superior and inferior vena cava, and coronary virus.
Left atrium ā same thickness as RA and forms most of the base of the heart. It receives blood from the lungs through four pulmonary veins.
Right ventricle ā about 4-5 mm thick and forms most of the anterior surface of the heart. Blood passes from the right ventricle through the pulmonary valve into the large artery.
Left ventricle ā is about 10-15 mm thick and forms the apex of the heart. Blood passes from the left ventricle through the aortic valve into the ascending aorta.