Chapter 14 of 14All chapters
Chapter 14 of 14
The immune system
Two layers of defence.
Innate and adaptive
The innate response is immediate and general: barriers, inflammation and cells that engulf anything foreign. The adaptive response is slower, learns a specific threat and remembers it.
- Antibodies mark a specific invader so other cells can destroy it.
- Memory cells are why a second infection is usually milder and faster to clear.
Vaccines and fever
A vaccine teaches the adaptive system without the illness. Fever is the body raising its own temperature to slow invaders down, which is a defence rather than a symptom to always suppress.