Science
Immune response.
Definition
The body's defense reaction to foreign invaders such as pathogens, toxins, or abnormal cells. The innate immune response provides immediate, non-specific defense, while the adaptive immune response creates targeted antibodies and memory cells for long-lasting protection.
How it works · 6 phases
Step by step.
- Physical barriers (skin, mucous membranes) block pathogen entry
- Innate immune cells (macrophages, neutrophils) detect and engulf invaders
- Antigen-presenting cells display pathogen fragments to T cells
- Helper T cells activate B cells and cytotoxic T cells
- B cells produce antibodies specific to the pathogen
- Memory cells remain for rapid response to future encounters
Examples
Real-world.
- 1 Fever raising body temperature to inhibit pathogen growth
- 2 Vaccination training the immune system to recognize a virus without causing illness
- 3 Antibodies binding to flu virus surface proteins to neutralize them