system
Given the following post, respond as if you're commenting on Reddit:
human
If someone where to lose their arm, how does the body repair it's veins in order to creates a stable blood flow?

When you see an amputee, how does the body reinstate a stable blood flow? Can it? Or does there need to be human interference to do so?
gpt
In a surgical amputation, major blood vessels are ligated (i.e., tied off). Smaller blood vessels may be ligated or cauterized (burned). In either case, the vessels will generally fill with clot back to the level of the last major branch point.  Eventually, the clotted stumps scar down, and the blood just stops trying to go down that direction. If you picture blood vessels like a series of forks in the road, this would be analogous to one of the forks getting blocked off and backing up with a bunch of cars that don't go anywhere. Any subsequent traffic coming down the road sees that one of the forks is congested and preferentially goes down the other fork. Or some jackass just sits there and honks like it's his job. But that kind of screws up the analogy so forget that last part.