system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: what stops someone from bleeding profusely when a surgeon cuts on them?
gpt
Not everything that carries blood is the same size. A tiny capillary may only bleed a few drops (like when you get a paper cut).


  Surgeons know a lot about your anatomy and where they can and can’t cut. They avoid cutting into blood superhighways (arteries and major veins) that would cause major bleeding and kill you.


If they do cut into a blood superhighway they have tools to plug it up like clamps

When they cut into very small capillaries that don’t bleed much they have tools which can cauterize the wound or you may stop bleeding on your own.