Pulmonary (lung) circuit:

1. The right ventricle pumps blood to the lungs

2. via the pulmonary arteries.

3. Blood in capillaries loads O₂ and unloads CO₂.

4. Oxygenated blood returns via pulmonary veins

5. to the left atrium and left ventricle.

Systemic circuit:

6. Oxygenated blood leaves the heart via the aorta

7. to capillaries in the head and arms, and also

8. to capillaries in the abdominal organs and legs.

9. Oxygen-poor blood returns via superior vena cava

10. and inferior vena cava, then empty

11. into the right atrium.

Review:

Exercise: