How do our bodies know when foreign objects are inside us? And how do they know when they are gone?

129 viewsBiologyOther

Like with viruses and food poisoning.

In: Biology

2 Answers

Anonymous 0 Comments

Cells have to interact with each other. 

To that end, the outside of them is covered with all sorts of connectors, mostly made of proteins.  Think of it like puzzle pieces. 

Your immune system is CONSTANTLY experimenting around with different kinds of connectors and it (mostly) builds ones that connect to things that aren’t supposed to be in your body. 

So, when it runs across something that doesn’t connect, like a shard of metal, or connects to one of those immune cells specifically designed to fit puzzle pieces that aren’t supposed to be there, like a virus, it reacts.  That reaction triggers other cells and a chain reaction known as an immune response begins. 

Every once in awhile the immune system accidentally makes cells that fit and thus trigger on something which isn’t dangerous. We call those allergies.  Sometimes it accidentally makes something that triggers on things you need, which we call auto-immune disorders. 

Very ELI5, but hopefully it helps

You are viewing 1 out of 2 answers, click here to view all answers.