Gas exchange

Definition

Gas exchange is the process by which oxygen is transported to cells and carbon dioxide is expelled from the body. It primarily occurs in the alveoli of the lungs where blood vessels facilitate this exchange.

5 Must Know Facts For Your Next Test

1. Gas exchange occurs in the alveoli, tiny air sacs within the lungs.
2. Oxygen diffuses from the alveoli into pulmonary capillaries while carbon dioxide diffuses from blood to be exhaled.
3. Efficient gas exchange requires a large surface area and thin respiratory membrane.
4. Partial pressure gradients of oxygen and carbon dioxide drive their diffusion during gas exchange.
5. Conditions like emphysema or pulmonary edema can impair gas exchange by damaging alveolar structures or increasing membrane thickness.

Review Questions

• Where does gas exchange primarily occur within the respiratory system?
• What two gases are involved in gas exchange, and how are they transported?
• How do diseases such as emphysema affect gas exchange?

Related terms

Alveoli:

Microscopic air sacs in the lungs where gas exchange occurs.

Partial Pressure:

The pressure exerted by a specific gas in a mixture of gases, crucial for driving diffusion.

Pulmonary Capillaries: Small blood vessels that surround alveoli and participate in gas exchange.