Biology 2

Immune System Interactive Physiology Worksheet

The Immune System: Immune System Overview

1. Pathogens are classified according to their size and where they are located in the body. List the five types of pathogens from largest to smallest:
• __________________________ • __________________________
• __________________________ • __________________________
• __________________________
2. Which type of pathogen is always intracellular? ________________ Which type of pathogen is always extracellular? ________________
3. Name the three main lines of defense and give an example of each:
|Line of defense |Example |
| | |
| | |
| | |

4. When the surface barriers (innate external defenses) are penetrated, what is the next line of defense? ___________________________
5. This defense mechanism (named in question 6) identifies enemies by recognizing ____________ unique to the pathogens. When they are overwhelmed, they secrete __________________ to mobilize the adaptive defenses.
6. Name the four key ways adaptive defenses differ from innate defenses:
• __________________________ • __________________________
• __________________________ • __________________________
7. B and T lymphocytes recognize pathogens by binding to them. What the lymphocyte recognizes is called the __________________ found on the antigen.
9. Specific B cells called _________ cells secrete ______________, which bind to the antigens.
Humoral Versus Cellular Immunity
10. ____________ immunity is directed against pathogens in the extracellular fluid. This immunity involves ___ lymphocytes.
11. ____________ immunity is directed against pathogens