Step by step blood flow in heat can be represented as follows
- Oxygen-poor blood returns from the body to the heart through the superior vena cava (SVC) and inferior vena cava (IVC), the two main veins that bring blood back to the heart.
- The oxygen-poor blood enters the right atrium (RA), or the right upper chamber of the heart.
- Then the blood flows through the tricuspid valve (TV) into the right ventricle (RV), or the right lower chamber of the heart.
- The right ventricle (RV) pumps oxygen-poor blood through the pulmonary valve (PV) into the main pulmonary artery (MPA).
- The blood flows through the right and left pulmonary arteries into the lungs.
- During the process of breathing, oxygen will be in the blood and carbon dioxide is taken out from the blood and thus the blood will be oxygen-rich.
- Oxygen-rich blood flows from the lungs back into the left atrium (LA), or the left upper chamber of the heart, through four pulmonary veins.
- The blood then flows through the mitral valve (MV) into the left ventricle (LV), or the left lower chamber.
- The left ventricle (LV) pumps the oxygen-rich blood through the aortic valve (AoV) into the aorta (Ao), the main artery that takes oxygen-rich blood out to the rest of the body.