Questions for Science... Question in Description?

Question

Why do parts of our body "fall asleap?"

Answer 1

The tingling sensation is the bodies nervous system signal that a part of the body has a reduced flow of arterial blood to it. This reduction may be due to a constriction or pressure on an artery cutting down or cutting off blood supply. Actually the tingling occurs when the blood flow starts again and is the response to cells becoming revitalized. The part with restricted blood flow may have had no feeling at all and been paralyzed for a time.

Answer 2

simply because they lack adequate blood supply