Breathing

Name: ______________________   Date: ____________

Use the clues to fill in the crossword.

Across

  1. 1. Red liquid pumped around the body by the heart (5)
  2. 7. Any of the smallest ___ ducts (plural) (11)
  3. 10. An alkaloid poison that occurs in tobacco (8)
  4. 11. Membranous tube with cartilaginous rings that conveys inhaled air from the larynx to the bronchi (8)
  5. 13. Plant dried and smoked in cigarettes (7)
  6. 15. The metabolic processes whereby certain organisms obtain energy from organic molecules (11)
  7. 16. Protective secretion of the mucous membranes (5)

Down

  1. 2. Gas in the air that we need to breathe (6)
  2. 3. Either of the two main branches of the trachea (8)
  3. 4. The organ of smell and entrance to the respiratory tract (4)
  4. 5. The act of supplying fresh air and getting rid of foul air (11)
  5. 6. The rhythmic contraction and expansion of the arteries with each beat of the heart (5)
  6. 8. Any of the minute blood vessels connecting arterioles with venules (plural) (11)
  7. 9. The power to do work or make things move (6)
  8. 12. To draw air into, and expel out of, the lungs (7)
  9. 14. Serious disease where cells grow out of control (6)