Gas Exchange across Respiratory Surfaces

Art Connections

Figure Which of the following statements is false?

  1. In the tissues, P O 2 drops as blood passes from the arteries to the veins, while P CO 2 increases.
  2. Blood travels from the lungs to the heart to body tissues, then back to the heart, then the lungs.
  3. Blood travels from the lungs to the heart to body tissues, then back to the lungs, then the heart.
  4. P O 2 is higher in air than in the lungs.

Hint:

Figure C