Across
- 2. the gas that is inhaled by mammals
- 4. windpipe of the respiratory system
- 6. major organ of the cardiovascular system
- 10. involved in swallowing, breathing, and voice production
- 12. the gas that is exhaled by mammals
- 13. the act of breathing in gas to fill the lungs
- 15. blood vessels that connect veins and arteries
- 16. the number of chambers in the heart
- 17. a flap of cartilage at the top of the trachea that covers the opening of the windpipe
- 20. side of the heart that is oxygen-poor (blue)
Down
- 1. the act of breathing out gas to expel the lungs
- 3. many tiny air sacs of the lungs which allow for gas exchange
- 5. major air passages of the lungs which branch off of the trachea
- 7. blood vessels that carry blood towards the heart from the lungs
- 8. the number of ventricles or atriums in the heart
- 9. smaller branches of the major air passages that extend off of the trachea
- 10. side of the heart that is oxygen-rich (red)
- 11. during exhalation, the thoracic cavity _____ in size
- 14. blood vessels that carry blood away from the heart
- 18. during inhalation, the thoracic cavity _____ in size
- 19. major organs of the respiratory system