13.19

Capillary blood to tissue cells

After the oxygen continually passes from the air of alveoli to capillary blood, it passes from __________

Diffusion

All gas exchanges are made by _____

Carbon dioxide-poor and oxygen-rich

As a result of such exchanges, arterial blood tends to be _____

Tissue cells to capillary blood; capillary blood to alveoli air

Conversely, carbon dioxide moves from the ______ and from ________

Air of alveoli to capillary blood

Thus oxygen continually passes from the _________

Oxygen-poor and carbon dioxide-rich

Venous blood is ________

Higher concentration, lower concentration

When substances pass in this manner, they move from areas of their ____ to areas of their _____