Inner workings of a centaur?

So I've been thinking about making a centaur race but because of how detailed i am I started thinking about their biology. While I want the creature to be as plausible as can be I was also trying to find a way to keep the flexibility of the upper torso and making them capable of lying down without fear of death from crushed organs. mostly for posing reasons.

I've already decided on making them omnivorous and using 2 hearts,1 major and 1 minor that merely assists, and i could easily stretch out the digestive system due to having a lot more room now which might lighten the load for the equine half. What has me stumped however are the lungs I don't quite know where or how to place them to match what i need, I've seen suggestions about having 2 sets but I don't even understand how those could function. at one point i was even thinking of adding a set of air holes that could be used to provide extra air while running.

I'm perfectly ok with modifying the creature ,so long as i'm able to maintain flexibility and avoid the weight issue. any and all suggestions are welcome.

If the digestive system and intestines are mostly in the equine half, you can probably give their space in the human half to the lungs. You want them bigger than what humans have, and probably patterned after those too as horse lungs are mechanically tied to their stride while in motion. (You can also fudge some details by saying that they're more efficient than human or horse lungs in providing oxygen to the bloodstream.)

Actually, you might want to keep them mechanically decoupled from locomotion. A lot of human vocal abilities such as laughter come from the fact that our lungs are divorced from our walking. Its why we're the only mammals who can laugh.

I once saw a fantasy biology sketch cross-section of a centaur, where the human part was basically only containing the lungs and oesophagus.

It made more sense to me if all the vital organs were in the human part, and the horse part pure locomotion power and all the biology that comes with it. Even though that might require some vital organs being in the horse part, like the heart (or two—or a liver-sized human heart in the human part maybe?) or the large intestine.

And centaurs probably have to eat a lot more than a person.

The problem with putting the lungs in the human torso is that they will not then be large enough to power the horse half (ditto for the digestive system). But it's unlikely that Centaurs can run as fast as horses anyway, given how their weight would be balanced.

agreed on both aspects. i'd think they'd be faster than a human but slower than a horse. if i make them slim like i planned too they might match a horse at best. (no need to keep all that extra room i theres no use for it.

I have seen so many sketches but not a single person can agree on how things should line up. centaurs would definitely require a lot of energy which is the reason i wanted to make mine omnivorous. more sources of available food for them that they could digest would make survival a bit more believable

that was actually the reason i looked at using 2 sets yet 2 sets of lung do not seem like they would work properly at all. I could possibly combine how the 2 look and act? handwaving might be necessary at this point.

As for organs, maybe a more bird-like respiratory system might work? The one I'm worried about is the digestive system, most humans don't weight over 100 kg, whereas a decent horse would be going on four times that, so the things would be constantly pigging out, which raises the question of exactly how mobile the waist is, since, a lot of natural food is down low (vegetables, most small animals, berries, etc), so they either have to bend over of lie down, both of which are very compromising positions should danger arise.

how so? I'll need some explanation on that respiratory system.

i stated earlier they're omnivorous so they should have easier access to food that would provide energy. i also stated that i wanted to keep flexibility so that shouldn't be an issue, hopefully once the lung situation settled these centaurs should be lighter and slimmer than the standard as well

For birds, full respiration takes two breatha, firth inhalation takes air into the posterior air sacs, which is then forced into the lungs on the first expiration, into the anterior air sacs on the second inhalation, and out on the second exhalation. None of this involves a diaphragm in and way because birds don't have those, everything being done by the rib-cage.

There's a basic video here, and several others around the place.

I don't know whether it would be enough to fill the whole 'human' body with respiratory gear, but it would reduce the weight a bit I imagine.

edited 4th Jul '15 3:59:28 AM by MattII

Is the ventral/posterior half going to be gazelle-like instead of horse-like?

I think that might make the biology slightly easier to figure out, but might add limitations as you've been prepared to compromise speed, what about the weight they can carry?

Extremely relevant link.

(Warning: Link may not actually be extremely relevant.)

Magic

But seriously, what about this link?

[1]◊

edited 8th Jul '15 4:29:38 PM by HydraGem

Link is busted (try dropping the curly brackets).

Okay, I got it working now-I guess.