2. The lungs are in the upper part of the body called the thorax

3. They are protected by the ribcage

4. The trachea, or windpipe, is held open by rings or cartilage

5. The bronchi are tubes leading into the lungs which also have rings of cartilage to keep them open

6. The alveoli provide a large surface area for gas exchange

7. The intercostal muscles are used in breathing

8. The diaphragm is a sheet of muscle which is important for breathing

9. The ribs protect the heart and lungs and are where the intercostal, or rib, muscles are attached

10. Review 1.Which is the correct of structures that air would pass through as it entered the lungs? C These air passages get narrower and narrower, ending at the alveoli

11. Which of the following labels is pointing to the alveoli? A, B is trachea and C is bronchus