Mammalian cardiovascular system.
Pulmonary (lung) circuit:
- The right ventricle pumps blood to the lungs
- via the pulmonary arteries.
- Blood in capillaries loads O2 and unloads CO2.
- Oxygenated blood returns via pulmonary veins
- to the left atrium and left ventricle.
- Oxygenated blood leaves the heart via the aorta
- to capillaries in the head and arms, and also
- to capillaries in the abdominal organs and legs.
- Oxygen-poor blood returns via superior vena cava
- and inferior vena cava, then empty
- into the right atrium.