2.9 - Lungs and Gas Exchange

• Which organ system are the lungs part of?

  Respiratory System
• What structures connect the bronchi to the alveoli?

  Bronchioles
• What are the tiny air sacs in the lungs called?

  Alveoli
• What is the name of the process by which oxygen moves through the wall of the alveoli into the blood?

  Diffusion
• How are alveoli adapted for efficient gas exchange?

  Their walls are only one cell thick, which provides a short distance for diffusion.

  There are many of them, giving a large surface area.

  They are moist, which allows gases to dissolve, and therefore diffuse more easily.
• Which gas diffuses from the blood into the air of the alveoli?

  Carbon Dioxide
• Which substance inside red blood cells does oxygen bind to?

  Haemoglobin
• Carbon Dioxide is transported around the body dissolved in the blood plasma.