Internal Resp. Gas Exchange

• Gas exchange in the alveoli

  1. Diffusion of carbon dioxide out of blood

  2. Diffusion of oxygen into blood
• Gas exchange in the alveoli takes place through the process of diffusion
• Material moves from an area of higher concentration to an area of lower concentration
• Blood that goes to the alveoli through the capillaries is poor in oxygen and rich in carbon dioxide
• Carbon dioxide in the blood

  Diffuses out of the blood into the alveoli
• This gas is released out of the body when you exhale
• Oxygen from the inhaled air inside the alveoli

  Diffuses into the blood
• The blood, which is now rich in oxygen and poor in carbon dioxide, leaves the alveoli
• The blood flows back into the heart which pumps the blood to be delivered to different parts of the body