Respiratory system

12345678910
Across
  1. 4. a muscle sheet underneath the lungs that contract when you inhale
  2. 6. The volume of the lungs would be increase when we inhale
  3. 8. a structure in the pharynx which prevent the food entering the trachea
  4. 9. air sac must be thin, large surface area , and __________ to allow efficient gas exchange
  5. 10. The ribcage contract and moves __________ when we exhale
Down
  1. 1. a site of gas exchange
  2. 2. The volume of the air which remain in the lungs after expiration
  3. 3. a blood which contain more oxygen than carbon dioxide
  4. 5. a cell which produce a mucus
  5. 7. a tiny small hair like structure which always swept away mucus toward the throat