Immune System and Other Body Defenses: Overview, The first line of defense: physical barriers, The second line of defense: the immune system, Other defenses, Immune responses and disease
What are the Three Lines of Defense?
Body defenses against infection | PPT
237 Ilustraciones de Body Defenses - Getty Images
The Four Lines of Defense — Immunology #2 | by Beth Howe | ILLUMINATION | Medium
Session 4: Immune defences against infectious diseases: View as single page | OpenLearn
Immune System Function, Conditions & Disorders
DARPA: Dialing Up the Body's Defenses Against Health Threats - American Security Today