1. The dome-shaped muscle under the lungs that flattens during inspiration is the __________________________________. 2. The double membrane that covers the lungs and lines the thoracic cavity is the...

1. The dome-shaped muscle under the lungs that flattens during inspiration is the __________________________________.

2. The double membrane that covers the lungs and lines the thoracic cavity is the __________________________________.

3. The small air sacs in the lungs through which gases are exchanged between the atmosphere and the blood are the __________________________________.