After oxygen diffuses into the blood, where does the saturated blood travel next?

After oxygen diffuses into the blood, where does the saturated blood travel next?

• A. To the capillaries in the muscles
• B. To the heart and then to the capillaries
• C. Directly to muscle cells
• D. To the lungs again

Answer: (B)

When blood has picked up oxygen in the lungs, it still needs the heart to drive circulation. The oxygenated blood goes to the heart first, where it’s pumped out into the body’s arteries and travels to capillaries in the muscles to deliver oxygen. Only after circulating through the body does it return to the heart (to be sent to the lungs again for another round). So the next step is to the heart and then to the capillaries. It wouldn’t go directly to muscle cells, and it wouldn’t go back to the lungs immediately.

When blood has picked up oxygen in the lungs, it still needs the heart to drive circulation. The oxygenated blood goes to the heart first, where it’s pumped out into the body’s arteries and travels to capillaries in the muscles to deliver oxygen. Only after circulating through the body does it return to the heart (to be sent to the lungs again for another round). So the next step is to the heart and then to the capillaries. It wouldn’t go directly to muscle cells, and it wouldn’t go back to the lungs immediately.