Eli5 why is it that if I cut myself with a knife I bleed like crazy, but when a surgeon cuts into a chest, removes the ribs to perform a major surgery you don’t see all that much blood comparatively?

Question

Eli5 why is it that if I cut myself with a knife I bleed like crazy, but when a surgeon cuts into a chest, removes the ribs to perform a major surgery you don’t see all that much blood comparatively?

In: 562

Answer 1

Ooh ooh I know this one having spent a little time in the OR. The skin on much of your abdomen and chest isn’t brimming with blood vessels like your fingers. And what you don’t see maybe is that someone is standing by with cautery to quickly zap any bleeders. Also they may have put in a local anesthetic that includes a second drug that shrinks the blood vessels in that area. It turns out using local nerve block reduces stress even though they are also using a general anesthetic.

I once tripped and a stick jammed itself through my leg skin. Like all the way in under the skin and then all the way out like a giant sewing needle. No blood. My dog does this too. He’ll go crashing through the brush and have like a huge tear in the skin. One time I saw his muscles moving! Took a bunch of stitches but zero bleeding