The oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. This blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. From the left ventricle, the blood passes through the aortic valve to the aorta.
1. Biosphere
2. Lithosphere
3. All of the above
4. i dont know
Red blood cells actually carry the nutrients
