system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do abrasions weep?

After hurting myself, I noticed that abrasions on the skin always produce a lot of fluid. Cuts or scratches usually never do that. What has a abrasion that something like that happens?
gpt
When tissues are damaged, part of the body's response is inflammation.  Inflammation includes increased blood flow to bring in nutrients and oxygen to start repair and white blood cells to clean up damaged cells and catch any invaders that may be in the wound.  Also, the surrounding blood vessels getting slightly leaky so that plasma (the clear, straw-coloured part of blood) get right up around the damaged area to provide a good environment for the white blood cells to work in and more direct access to the nutrients that are dissolved in the plasma.

When you get a cut or scratch mostly you see blood, but sometimes you might still get a little plasma seepage after the bleeding stops.  In abrasions you haven't damaged deep enough to get good bleeding going, but still get the inflammation related seepage.  Abrasions also tend to be over larger areas so it takes longer for clotting to take place and stop all the leaking.