Comment on Would having two hearts be better or worse for the human body?
AbouBenAdhem@lemmy.world 5 days ago
It’s better, which is why we already do.
Mammals have a double circulatory system, with the left and right ventricles effectively acting as separate hearts that happen to be physically connected.
deranger@sh.itjust.works 5 days ago
Citation needed. The junctions in cardiac cells make electrical signals propagate through them all, so acting independently isn’t something that’s normal. There’s two loops, but one pump. It’s a single system.
AbouBenAdhem@lemmy.world 5 days ago
Even if they were physically separated you’d want them to pump in sync, to maximize the pressure. So having them share electrical signals is just the optimal setup for two hearts.
HeyThisIsntTheYMCA@lemmy.world 5 days ago
you want to maximize flow, not pressure. maximizing pressure is a great way to die of stroke.
AbouBenAdhem@lemmy.world 5 days ago
Not absolute pressure, but pressure per unit of work (i.e., efficiency).
FistingEnthusiast@lemmynsfw.com 5 days ago
You’re being needlessly pedantic
The reality is that they’re two hearts
If they were to be carefully separated, but with the SA & AV nodes still connected somehow (ignoring the fact that the Perkinje fibres and bundle of hiss can also act as pacemakers), you’d have two separate hearts doing their thing
deranger@sh.itjust.works 2 days ago
Well they’re not separated, so who’s really making the pedantic argument here?
Onomatopoeia@lemmy.cafe 5 days ago
But if the nodes are connected, it’s still a single pump.
You’re merely choosing to redefine the terms. The nodes are part of the heart as a system - remove the nodes and well, the pump no longer pumps.
Your argument is like saying you can split a multi-cylinder automotive engine in half, leave the ignition system in place, and you have 2 engines.
No, you have one engine split in two, with it’s electrical timing system still determining how each cylinder maintains the exact same timing as before.
(Automotive engines are essentially air pumps with very specific timining mechanisms, as each cylinder’s output affects other cylinders, akin to the timing in a heart).