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Terr_ t1_ixlkxhy wrote

Another metaphor:

Suppose you have a thousand planks of wood in nice stacks. You can store them and still be okay if a random 10% become rotted and must be thrown out.

Now imagine you store a house made out of a thousand planks of wood, and again 10% of it rots. It might become dangerously weak, and it will be very expensive to check and replace the bad parts.

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_googlefanatic_ t1_ixlmglt wrote

But I don't understand , why does a few cells destroyed in a tissue affect the tissue , the cells can re divide , right? If not then why so ?

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wedontlikespaces t1_ixlnbah wrote

Because when they're independent cells they are independent but when they're in a tissue they're part of a larger structure, so if that larger structure is damaged the whole tissue becomes nonviable.

If 10% of a heart dies, then the entire heart no longer works.

Going back to the house example, if a structural support beam is one of the 10% of wooden beams that rots, then the whole house is going to fall down. It's not a perfect analogy because obviously there's some bits of wood which are more important than others, but you get the idea.

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Terr_ t1_ixlnrjg wrote

Many of the cells in your body have stopped dividing, they've settled into specialized roles and positions and will not "fill in the gaps" by duplicating to replace missing neighbors. The shape of everything else around them and the signals from their neighbors cause them to act in certain narrow ways. When they don't do that and start dividing again, that's often cancer.

New cells are usually generated from deeper spots, from special cells with the job of just churning out certain kinds of gradual replacements.

So if you choose a random zone of tissue and kill some cells in it, those gaps or weaknesses may persist in that area until everything around it is pushed out and replaced by the march of fresh cells from further in.

If you damage one of those special zones where new cells are still being made, the damage could be permanent, like getting a scar on your skin that lasts even when almost all of the cells have been replaced over time.

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_googlefanatic_ t1_ixlu4ze wrote

Got it , but It should be rare right ? Like when we damage the exact location ....

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Ishana92 t1_ixm22tp wrote

If you had time to repair all the damage it would be fine, probably. But those cells that died are releasing all sorts of messages to neighbouring cells. It's not just that they died and now there is a hole to fill, it's that now there is a hole and neighbouring cells are also freaking out and not doing their job. And then if you have living organism the immune response is going to kick in and just go crazy at site that is damaged. You get the whole cascade when cells are all dependent.

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TEW20 t1_ixmthod wrote

Not necessarily, some structures never regenerate and scar tissue forms where the damage happened, so that part of the tissue never recovers it's function. That's why damage to some organs cannot be repaired.

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