The heart has the following five surfaces:

• Posterior surface - corresponds to the base of the heart;
• Diaphragmatic surface - inferior surface;
• Sternocostal surface - anterior surface;
• Left pulmonary surface - left lateral surface;
• Right pulmonary surface - right lateral surface.

Diaphragmatic surfaces

In its anatomical position, the heart rests on its diaphragmatic or inferior surface. This surface faces inferiorly and lies on the central tendon of the diaphragm and left muscular hemidiaphragm. It is formed mainly by the left ventricle and a small part of the right ventricle, and both are separated by the posterior interventricular sulcus. The coronary sinus separates the diaphragmatic surface from the base of the heart and right pulmonary surface.

Sternocostal surface

The sternocostal or anterior surface faces forward, upward and slightly to the left. It is formed mainly by the right ventricle and right atrium, and this surface also has a minimal contribution from the left atrium and left ventricle.

Pulmonary surfaces

The two pulmonary or lateral surfaces are broad and convex, and they both face the lungs.

• The left pulmonary surface is formed mainly by the lateral part of the left ventricle.
• The right pulmonary surface consists mainly of the lateral portion of the right atrium.