When you are discussing zombies, you would be using pseudo science. The game already has zombies which were cut open, with blood being spilled, but they still survived. So the circulation is not an issue.
In fact, the organs aren’t really required. In the original Zombie Exodus, there were zombies in an area where the humans died of suffocation, but the zombies were fine.
So it is possible to explain some of the stuff with science, but there will be a point where the player has to do the ‘suspension of disbelief’ where things like zombies are involved.
As far as what I’ve seen in zombie exodus, no. However, @JimD can certainly decide otherwise.