I’ll open by saying that I’m no physicist, but I know that free fall is zero gravity. Sounds odd when there is so much wind resistance, but whether you are at terminal or not, if you are in free-fall, you are in zero-g. This is stated in the equivalence principal of physics. Being in a state of zero gravity in free-fall, I would speculate that blood would flow even more freely than it does when we are on the ground.
“Counterintuitively, a uniform gravitational field does not by itself cause stress or strain, and a body in free fall in such an environment experiences no g-force acceleration and feels weightless. This is also termed zero-g.”
http://en.wikipedia.org/wiki/Weightlessness
and
http://en.wikipedia.org/wiki/Equivalence_principle