Across
- 2. a large tube filled with cartilage, this is the second step in the respiratory system
- 3. the action of breathing in
- 5. the system that allows you to breath and sends your muscles oxygen
- 6. are the center of the respiratory system
Down
- 1. a skeletal muscle that contracts and flattens under your lungs
- 4. any of the major air passages of the lungs which diverge from the windpipe