Across
- 6. sheet of muscle that separates chest cavity from abdominal cavity
- 7. sensory filter of vertebrate brain
- 9. voice box
- 13. system of breathing in which lower air pressure causes air to enter lungs
- 15. relay point between neurons or neuron and effector cell
- 17. part of an animal where O2 from the environment diffuses into living cells and CO2 diffuses out to the surrounding environment
- 19. relaxation phase of the heart
- 21. chamber of heart that pumps blood
- 22. carries blood between heart and the rest of the body
- 25. brain and spinal cord in vertebrates
Down
- 1. many tiny sacs where gas exchange happens in lungs
- 2. converted from fibrinogen to clot blood
- 3. protein with iron that transports oxygen
- 4. tiny blood vessels that run in all parts of the body
- 5. conductor of heartbeats also known as the sinoatrial node
- 8. folded tissue layer that forms the surface of the cerebrum
- 10. blood vessels that return blood back to heart
- 11. pumps fluid through open end tubes to flow through cells
- 12. chemical messenger that carries information from a neuron to a cell
- 14. detects pacemaker impulses
- 16. number of heart beats per minute
- 18. controls pituitary gland and hormone secretion
- 20. windpipe
- 23. also known as white blood cells
- 24. coordinates body movement with cerebrum