Across
- 1. tube that carries air from the larynx to the bronchi
- 3. gas exchange between the body's cells and the blood
- 5. mechanical movement of air into and out of the lungs
- 6. heart's sinoatrail node, which initiates contraction of the heart
- 9. hemoglobin-containing, disc-shaped, short-lived blood cell that lacks a nucleus and that transports oxygen to all the body's cells
- 12. large, nucleated, disease-fighting blood cell produced in the bone marrow
- 15. a blood vessel that carries deoxygenated blood back to the heart
- 16. gas exchange between the atmosphere and the blood, occurring in the lungs
- 17. flat cell fragment that functions in blood clotting
- 19. one of the two large tubes that carries air from the trachea to the lungs
- 20. nitrogenous waste product of the excretory system
Down
- 2. circulatory system disorder in which arteries are blocked, restricting blood flow
- 4. microscopic, one-cell-wall thick blood vessel where exchange of materials occurs between blood and body cells
- 7. clear, yellowish fluid portion of the blood
- 8. one of the tissue flaps in veins that prevents backflow of blood
- 10. in the lung, a thin-walled air sac surrounded by capillaries
- 11. hollow, muscular organ that pumps oxygenated blood to the body and deoxygenated blood to the lungs
- 13. largest respiratory system organ in which gas exchange takes place
- 14. bean-shaped, excretory system organ that filters out wastes, water, and salts from the blood and maintains blood pH
- 18. elastic, thick-walled blood vessel that carries oxygenated blood away from the heart