Communicable Diseases

2. An infection of the lungs in which the air sacs fill with pus and other liquids.
7. The lining of various body cavities, including the nose, ears, and mouth.
9. A yellowing of the skin and eyes.
11. An occurrence of a disease in which many people in the same place at the same time are affected.
15. The passageway that makes breathing possible.
16. White blood cells that attack invading pathogens.
18. The state of being protected against a particular disease.
19. Communicable diseases whose occurrence in humans has increased within the past two decades or threatens to increase in the near future.
20. Single-celled microorganisms.

1. A disease that is spread from one living organism to another or through the environment.
3. A substance that kills cells or interferes with their functions.
4. An organism that carries and transmits pathogens to humans or other animals.
5. A reaction to tissue damage caused by injury or infection.
6. A network of cells, tissues, organs, and chemicals that fight off pathogens.
8. A microorganism that infects the digestive system.
10. Scarring of the liver tissue.
12. Substances that are capable of triggering an immune response.
13. A global outbreak of an infectious disease.
14. Specialized white blood cell that coordinates and performs many of the functions of specific immunity.
17. A piece of genetic material surrounded by a protein coat.