Adult sheep (ovine) heart

Sheep (ovine) heart, viewed from the left side if it were in the body. The heart consists of four chambers through which blood flows; two upper chambers (atria; blood enters the heart through these) and two lower chambers (ventricles; blood exits the heart through these). The outer surface is visible here together with the aortic arch, pulmonary artery (artery that carries deoxygenated blood from the right ventricle of the heart to the lungs; also known as the pulmonary trunk), atria (also known as auricles) and coronary vessels (blood vessels that supply the heart with blood). The heart measures 14 cm from base to apex.