In The Walking Dead (and most zombie movies), the zombies reanimate and then are able to walk again, eat again, and see again without respect to any injuries the person received before "dying." How does a reanimated being walk if the heart or certain muscles is destroyed? Clearly in many shots of the zombies we see little if any blood from the zombies. In the early part of the series, we would see half-stumps of people, dead people with large chest wounds, or dead people with partially eaten, injured or decomposed muscles that attempt to get Rick or other survivors.
What is evident is that circulation is not happening or possible in many cases. In living creatures, circulation of blood is what keeps motion possible. We know from having a foot or other limb "go to sleep" that we cannot move that limb until we get circulation back. Does the brain and nervous system become strong enough to "shock" the body into moving? how does that sustain without circulation? what happens then if the spine was severed?
Thanks for going on this trip with me!