Gas Exchange
Gas exchange takes place by diffusion through alveoli into blood.
The different percentage of nitrogen, oxygen, carbon dioxide, and water vapor in the air accounts for different pressure levels, which determines how these gasses will diffuse.
When you breathe in, the pressure of oxygen is higher in alveoli. This causes the oxygen to leave the alveoli and diffuse into the blood. The pressure of carbon dioxide is is higher in the blood, so it will diffuse into the alveoli.
This process occurs in the cells throughout your body.
When you breathe in, the pressure of oxygen is higher in alveoli. This causes the oxygen to leave the alveoli and diffuse into the blood. The pressure of carbon dioxide is is higher in the blood, so it will diffuse into the alveoli.
This process occurs in the cells throughout your body.
Hemoglobin
98.5% of oxygen in your body is carried on hemoglobin molecules. Each hemoglobin molecule carries about 2 oxygens. This is what delivers oxygen throughout your body.