3 1.2 The Physiology of the Cardiovascular System

The heart is comprised of two types of compartments, the atria and the ventricles. The atria are chambers where blood is collected from the veins before being pumped into the ventricles. The ventricles forcefully pump blood out of the heart (Silverthorn et al.). The right atrium receives deoxygenated blood from the inferior and superior vena cavae during systole (Silverthorn et al.). Deoxygenated blood that arrived from the body then passes through the first atrioventricular (AV) valve, the tricuspid valve (Silverthorn et al.). The right ventricle pumps the deoxygenated blood through the first semilunar valve (SV) into the pulmonary artery, which conducts the plasma towards the lungs (Silverthorn et al.) during diastole. Blood that returns to the heart by the pulmonary veins is oxygenated, which enters the left atrium, passes through the bicuspid AV valve and then enters the left ventricle (Silverthorn et al.).  The left ventricle pumps plasma through the aortic SV into the aorta in order to be distributed systemically (Silverthorn et al.).

Figure 4. A portrayal of the anatomy and circulation of the heart.