The immune system uses several kinds of defence. Barriers help keep microbes out, broad responses can react after entry, and specific responses recognize particular features. Some responses leave memory for a later matching encounter. That memory is not a defence against every different microbe.
The human body · Discover & try
How do different defences work together?
Reading level 1 of 5 · EarlyChange
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Innate
Broad defence mechanisms present without a new specific memory.
Immune memory
Cells retained after some responses that can recognise particular features.
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See how it works
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Conceptual defences shown in separate panels; real responses overlap. Invented symbols and timing do not predict illness or protection.
What to look for
- Barriers, broad responses and specific recognition contribute different defences.
- The memory route refers to a matching feature; it does not mean protection from everything.
Explain what you noticed
A memory cell recognises symbol M, but a new invader has a different symbol N. What can you conclude?
Keep this idea: Broad defences and specific recognition cooperate; immune memory is not a universal match.
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Source material checked 2026-10-29. Explanations and activities by Nepedia. Source links do not imply endorsement.
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