Main Parts of the Body’s Defense
- Skin: Acts as a tough outer wall to stop germs from entering.
- White blood cells: Patrol the blood and tissues to hunt and destroy bad invaders.
- Lymph nodes: Small bean-shaped glands that trap germs and clean fluid.
- Bone marrow: Soft tissue inside bones that makes new blood cells.
- Spleen: An organ that filters the blood and fights infections. [1, 2, 3, 4, 5]
How the Defense Works
- Innate immunity: The general defense you are born with that attacks any intruder right away.
- Adaptive immunity: Learned protection that grows over time as your body meets specific germs.
- Antibodies: Special proteins made by B cells that lock onto germs and mark them for destruction.
- T cells: Special cells that find and destroy infected or unhealthy body cells. [1, 2, 3]