1. What is the purpose of the lungs?

To get oxygen in the circulatory system.

2. How does oxygen get from the lungs to where it is needed in the body?

By the circulatory system.

3. Suggest a reason why the lungs are so close to the heart.

So the pressure of the heart is more effective.

4. Explain what the diaphragm is for and how it helps us.

It inflates the rib cage. It helps us by letting more air go into the lungs.

5. Explain why the alveoli have such a large surface area (70 square metres for the average human).

Because it is scrunched up so it can diffuse more.