What happens?

Question

If blood flows through the entire body then what happens when a limb is cut off? Since the vein or veins that the blood is flowing through is cut off, then how does the blood finish its course? Do doctors redirect it? Or does blood stop flowing to that part of the body? I need to know its driving me crazy!!

Answer 1

The arteries branch into smaller and smaller vessels until they are capillaries and then they get bigger and bigger until they are veins. When you cut off or lose a part, the part that is still there will have capillaries. Most places have blood supply from more than one source (for example in your hand there is a connection between the ulnar and radial arteries and in the brain there is the circle of Willis) But if you interupt the blood flow through a "terminal artery" then no blood will flow and the part supplied with blood will die. Think stroke, heart attack, mesenteric ischemia, etc.

Answer 2

You could say "it's not all a one way street" and when this happens the body sometimes has a unique way of stopping the blood flow (most of the time) Civil war soldiers were fortunate in having this happen and by the time the inept surgeons got around to them, if they didn't die of shock first, sepsis, or gangrene, they lived through the horror of having the limb cut off and living, then there was the problem of the infections, after using the same knives and saws on dozens of men, it's surprising how many did live.

I saw a man that was pinned between a boxcar and a loading platform for three hours. He blood and pressure was enough to sustain life, they brought his wife to see him, he spoke with a priest. The small town doctor gave him double shots of morphine, I know from 'Nam it was enough to kill him but, no one said anything. When they pulled the boxcar away, he was already dead, he died peacefully but, his heart was pumping blood.