PATHOLOGY

Detailed explanation-1: -Three layers of tissue form the heart wall. 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-2: -The external structures of the heart include the ventricles, atria, arteries and veins. Arteries carry blood away from the heart while veins carry blood into the heart. The vessels colored blue indicate the transport of blood with relatively low content of oxygen and high content of carbon dioxide.

Detailed explanation-3: -The inferior or diaphragmatic surface of the heart forms a roughly straight plane or slight concavity that projects to the left and slightly inferiorly to the apex of the heart. It lies superior to the central tendon of the diaphragm and at its lateral projection, the muscular part of the left hemidiaphragm.