My theory is that the lungs are modified to become massive viral factories that produce stem cells that are passed on from infected cell to cell due to the lack of blood flow and preserve the cells without the aid of oxygen. This also has an effect on their moan. When they moan due to the lungs being filled with stem cells some viral particles are released to put down a scent for other zombies.


Reply from smilerwithaknife: Zombies do not need to breathe because they are not alive. All of the cells in their bodies are dead. There are no stem cells, no blood flow, no preservation of cells. While the lungs continue to function, it is not for the process of extracting oxygen and expelling carbon dioxide (the continuous operation of the lungs is what allows the zombie to moan when sighting prey). Max Brooks explains this much better than I could inThe Zombie Survival Guide, which should be required reading for everyone on this site.

DOXKID: Do not mix normal biology with undead creatures. The moment the heart stops in humans and the brain shuts down, most biology having to do with that single organism has done it's job and quits. Fungi and such still consume it, but i don't even want to pretend like anyone here can properly understand and combine both natural biology and magical undead.

IFB254- Now hang on. We all agree that the best possibility is to destroy the brain. And if the brain still controls the body, even in the most rudimentary sense. To work, the cells need oxygen. Oxygen comes from breathing. I'm not discounting the possibilities stated above, just reasoning. There is the possibility that the lungs only focus on supplying oxygen to the brain, that's it, but I find it a little hard to believe. I mean, don't viruses need oxygen?

LordCohliani- Yea! Doesn't the brain need oxygen to survive? And how can zombies move their muscles without oxygen? I think zombies DO need oxegen...

Original-Sin - Almost every living substance on this Earth has some form of respiratory system, Plants, Animals, we Humans for examples. Zombies need their lungs for SEVERAL reasons, the two most common being for the function of their brain (the above posts are right... the lungs help pump oxygen to the brain, ceasing this would cease all functions of the ZED... no lungs, no brain) and for instinctive communication (moaning to attract other zombies I believe). Smilerwithaknife, if your going to talk about that JOKE of an 'author' Max Brooks, please know in his horrible survival guide (with probably more than half the facts in it wrong (not on zombies, on other things like weapons) ) he states that the virus doesnt CREATE life, it ALTERS it. The cells are still alive (by fictions standards)... otherwise they would start to rot and crumble away in a matter of weeks, making all the films a fallacy, considering there wouldn't be zombie fiction without the films for it to be based off of, it would prove everything we know about them wrong. Zombies need air just as much as we do, after all... we are the exact same (with the exception of a VIRUS). VIRUS ZOMBIES ARE NO MORE DIFFERENT THAN US... THAN YOUR MOTHER WHEN SHE HAS THE FLU... LEARN IT, LOVE IT.