Immune System Overview

Purpose of the Immune System

• Primary function: Protect the body from pathogens (shady proteins, viruses, bacteria, eukaryotic parasites, fungi).
• Defense mechanisms: Prevent entry of pathogens or eliminate them if they get in.

Lines of Defense

First Line of Defense (Non-Specific/Innate Immunity)

• Goal: Keep pathogens out.
• Components:
  • Skin: Barrier; oils are slightly acidic to inhibit bacteria.
  • Mucus Membranes: Contain chemicals to hamper bacterial survival.
  • Acidic Environments: Stomach acid, part of the body's