By Ariana Elkins and Alyssa Perkins. The Immune System . Infectious Diseases. Infectious diseases occur when microorganisms cause physiological changes that disrupt normal body functions. Infectious diseases can be caused by viruses, bacteria, fungi, “protists”, and parasites.
By Ariana Elkins and Alyssa Perkins
The Immune System
Non- Specific Defenses
Fighting Infectious Diseases