1. How much oxygen is found in inhaled air?

    10%

    20%

    30%

    40%

2. A bronchiole is smaller than a bronchus.

    True

    False

3. Our trachea is kept open at all times by .

4. Name the valve found between the right atrium and right ventricle.

5. A vein has:

    thin walls and no valves.

    thick walls and no valves.

    thick walls with valves.

    thin walls with valves.

6. What is red pigment in the blood called which combines with oxygen?

7. Blood leaves the heart to go to the lungs in the aorta.

    True

    False

8. Which of the following features is false of the alveoli.

    they present a large surface area.

    they have a dry lining.

    they have a thin lining.

    they have an excellent blood supply.

9. The muscles found between the ribs are called the muscles.

10. When we exhale, which of the following happens?

    rib cage moves up and out, diaphragm moves down.

    rib cage moves up and out, diaphragm moves up.

    rib cage moves down and in, diaphragm moves down.

    rib cage moves down and in, diaphragm moves up.