Health 3

2. Largest part of the brain; controls thinking, reasoning and memory.
3. Sound waves travel from the outer ear through the...to reach the eardrum
4. Bacteria and viruses that cause disease
7. Receptors that send messages to your brain which allow you to smell
10. The body's ability to resist a particular disease
12. Gives the eye its color
13. A person trained to examine eyes and prescribe glasses
14. Becomes thicker when you look at close objects and thinner when you look at distant ones
16. Tough outer layer of the eye
18. The special kind of skin cells that line your mouth, nose, and throat.
21. White blood cells inside lymph nodes
22. Nervous system consists of the brain and spinal cord.
23. Like wires; communication system.

1. The chemical which destroys most of the harmful bacteria that enter your stomach
5. The largest lymphatic organ
6. The enzyme that kills bacteria in your tears and perspiration
8. Transportation tubes for lymph
9. The hairlike projections that line the mucous membrane
11. Center of the iris through which light passes
15. The largest organ of your body.
17. Enlarged bunches of lymphatic tissue
19. Carries messages to your brain causing you to hear
20. Hollow space in your skull that surrounds each eye