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What is the immune system?
Medicine & HealthLesson on requestFree to read
Quick answer
The immune system is the body's defense network — a coordinated set of cells, tissues, and organs that detects and destroys harmful invaders like bacteria and viruses, and learns to recognize threats it has met before. Innate immunity is the fast, general first line (skin, inflammation, cells that attack anything foreign).
Key things to understand
- Innate immunity is the fast, general first line (skin, inflammation, cells that attack anything foreign).
- Adaptive immunity is slower but specific: it makes antibodies tailored to one pathogen and remembers it.
- White blood cells such as T cells and B cells coordinate the response.
- 'Memory' cells let the body respond much faster next time — the basis of how vaccines work.
People also ask
What are antibodies?
Proteins the immune system makes that lock onto a specific pathogen to neutralize it or tag it for destruction.
What's the difference between innate and adaptive immunity?
Innate is the fast, general defense you're born with; adaptive is the slower, specific defense that learns and remembers particular threats.
How does the immune system remember diseases?
After fighting a pathogen it keeps memory cells that recognize it, enabling a much faster response if it returns.
How does the immune system protect us?
It recognizes germs as foreign, destroys them with white blood cells and antibodies, and remembers them for a faster response next time.
What weakens the immune system?
Poor sleep, chronic stress, poor nutrition, and some illnesses can all reduce how well it works.
How do vaccines help the immune system?
They show it a harmless piece of a germ so it builds memory and protection without you getting sick.