I think I've over simplified the bird method but basically they inhale and exhale at the same time as required. They literally have double ended lungs, you push air in at one end and exhale CO2 at the other end. We mammals use the same route in and out of our lungs and the whole thing is driven by our diaphragm which pumps the bottom of our pleural cavity.
The bird mechanism is obviously efficient for oxygenation but it must have a cost that our body plan discarded or at least failed to even consider many millennia ago.
> ... it must have a cost that our body plan discarded ...
Our body plan didn't discard this mechanism, any more than it discarded wings or beans. We never had any of those features in our ancestry, because mammals aren't descended from birds. Our most recent common ancestor is much, much earlier than bird ancestors began evolving any mechanisms related to flight or high-altitude breathing.
Is this 'just' continuously blowing out from air stored in cheeks, while breathing as normal through the nose? I have said 'just', but it doesn't seem easy!
It doesn't seem to me that the lungs are being used differently (to normal breathing). I could be wrong.
(Edited to add text in parenthesis in 3rd sentence)
Yes, take a glass of water and fill your mouth, pretend to be a fountain spitting a stream of water, and breath through your nose. That is how I was tought to learn it anyways.
1) jet engines are interesting because of the continuous flow and also that all the rotating parts rotate in the same direction, a huge advantage over reciprocating engines. So jet engines can do 50,000 rps, while piston under 20,000 rps.
Note that sleeve piston engines like the Rolls Royce Crecy, are much more efficient than valves, but development stopped at the end of WW2 and resources focused on jet engines.
Rolls Royce Crecy - The Most Advanced Piston Aero Engine Never Made
2) the exception to continuous flow is the WW2 V-1 pulsejet engine, which has a gate that is closed at combustion time, about 42 Hz.
The pulsejet is a very interesting engine in that it's the simplest possible jet engine - literally an empty metal tube with spray nozzles and a sparkplug.
The V-1 was the first mass-produced cruise missile. The Germans also had air-to-ground (anti-ship) guided missiles both wire-guided and radio-guided with a TV screen(!)
But the US Navy was the first to build precision-guided autonomous missiles, both the all-analog Sidewinder and Wall-eye, which shared modules. The Wall-eye made the famous Gulf War photos you've seen of entering via windows. It had analog circuitry to do edge-detection in real-time.
Well this seems interesting... So from my knowledge of high school honors bio, blood vessels have these long slow muscles that also help pump blood. If a heart pumps continuously, wouldn't that create back pressure on the vein/artery muscles, which would in turn increase your blood pressure whenever the vessel muscles contract to pump? And if you got an artificial heart, I'd think higher blood pressure is a bad thing?
From my quick research just now, it seems continuous flow hearts are not better because they pump differently. That's just a side effect with no benefit that's noted in studies. A continuous pump is much smaller, and for long-term total heart replacement, is the only thing that can be small enough to fit in the body. In fact, it's noted in a case study that they're not sure about the long term effects of not having pulses, and that's something that will need to be studied.
Now as far as the lungs - I think that would be a bad idea too. We'd need separate flow-through pathways to inhale and exhale. So two necks, or an exit hole in the chest. That takes up space and is another vector for infection. In addition, exhaling moisturizes the tissue, so you'd need much harsher intake tubes, and your exhale tubes would be constantly dripping water. All that extra space has to come from somewhere - meaning you now have less space for actual oxygenating tissue, resulting in worse oxygen capture. Now the diaphragm has to pump harder, because you're not extracting as much oxygen from your air intake.
Anywise, you had a funny comment, which I hopefully made funnier by responding to it seriously. We're a good team. Team Heart & Lungs they call us.
Yes, Medlife Crisis talks about the issue of continuous flow artifixcal heart and mentioned that work is happening on one than mimmics the heart better in one of his videos.
so when I google "medlife crisis continuous flow heart," the first result is your comment. the one i'm replying to right now. which is pretty funny. do you have a link or good thing to search for, because I can't find it on the 1st couple of pages of results. not "asking for a source" - just bored and looking for something to read.
