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

1. When we put you under general anaesthetic your blood pressure drops so you’re not pumping your blood round your body as hard and it oozes/bleeds less. Slow moving bleeds clot, so little bleeding vessels don’t even need cautery. If your BP goes up during the op, the surgeon will give the anaesthetist a “yo bro, slow the flow” look before continuing because the bleeding increases and it’s harder to see and get a grip on things.
2. Choosing where to cut to avoid major vessels
3. Cautery
4. Clamps for larger vessels. We can stitch them closed too if they’re damaged.
5. In some operations they can even block the blood flow completely by clamping off arteries or blowing up medical balloons inside the vessel further upriver