this post was submitted on 10 Oct 2023
51 points (89.2% liked)

No Stupid Questions

35810 readers
1636 users here now

No such thing. Ask away!

!nostupidquestions is a community dedicated to being helpful and answering each others' questions on various topics.

The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:

Rules (interactive)


Rule 1- All posts must be legitimate questions. All post titles must include a question.

All posts must be legitimate questions, and all post titles must include a question. Questions that are joke or trolling questions, memes, song lyrics as title, etc. are not allowed here. See Rule 6 for all exceptions.



Rule 2- Your question subject cannot be illegal or NSFW material.

Your question subject cannot be illegal or NSFW material. You will be warned first, banned second.



Rule 3- Do not seek mental, medical and professional help here.

Do not seek mental, medical and professional help here. Breaking this rule will not get you or your post removed, but it will put you at risk, and possibly in danger.



Rule 4- No self promotion or upvote-farming of any kind.

That's it.



Rule 5- No baiting or sealioning or promoting an agenda.

Questions which, instead of being of an innocuous nature, are specifically intended (based on reports and in the opinion of our crack moderation team) to bait users into ideological wars on charged political topics will be removed and the authors warned - or banned - depending on severity.



Rule 6- Regarding META posts and joke questions.

Provided it is about the community itself, you may post non-question posts using the [META] tag on your post title.

On fridays, you are allowed to post meme and troll questions, on the condition that it's in text format only, and conforms with our other rules. These posts MUST include the [NSQ Friday] tag in their title.

If you post a serious question on friday and are looking only for legitimate answers, then please include the [Serious] tag on your post. Irrelevant replies will then be removed by moderators.



Rule 7- You can't intentionally annoy, mock, or harass other members.

If you intentionally annoy, mock, harass, or discriminate against any individual member, you will be removed.

Likewise, if you are a member, sympathiser or a resemblant of a movement that is known to largely hate, mock, discriminate against, and/or want to take lives of a group of people, and you were provably vocal about your hate, then you will be banned on sight.



Rule 8- All comments should try to stay relevant to their parent content.



Rule 9- Reposts from other platforms are not allowed.

Let everyone have their own content.



Rule 10- Majority of bots aren't allowed to participate here.



Credits

Our breathtaking icon was bestowed upon us by @Cevilia!

The greatest banner of all time: by @TheOneWithTheHair!

founded 1 year ago
MODERATORS
 

I have wondered many times how a human would fare if the kidneys dumped urine into the start of the large intestines somewhere about the appendix instead of into a bladder to be sprayed out. I'm assuming water would be reabsorbed and slower to process out, primarily through sweat and evaporation from the lungs, and maybe diarrhea, though it may be that other waste products, such as salts or ureas may be absorbed into the large intestines instead of being ejected, though I have no idea if it would, or if it would be ejected as intended. Do we have any biologists here that could give insight on if combining both waste paths into one would be advisable?

all 42 comments
sorted by: hot top controversial new old
[–] readyno@lemmy.world 57 points 1 year ago (4 children)

Am doctor, you are essentially asking about a fistula (abnormal communication) that would allow urine and bowel to mix. This would allow for communication of gut bacteria to then invade the urinary system which would then easily cause a kidney infection which would then seed the blood resulting in bacteremia. Bacteremia is bad, like you die from infection unless you are on IV antibiotics and get the source under control bad. As an example, colovesicular fistula is a communication between the colon and bladder which often results in bad infections and needs to be surgically repaired. Hope this helps.

[–] Delphia@lemmy.world 22 points 1 year ago (3 children)

Ok but why cant I have a secondary urethra grafted in that runs in my leg down to a nice discreet exit on my ankle so I can take a sneaky wee when Im out and about.

[–] finthechat@kbin.social 12 points 1 year ago (2 children)

You could just tape a garden hose to your dick and run it down a pant leg. Man, I should patent this idea....

[–] roguetrick@kbin.social 8 points 1 year ago

That's called a condom catheter. Don't hook it up to suction.

[–] Resistentialism@feddit.uk 1 points 1 year ago

I can't. Hose widths are too big.

[–] Thurkeau@lemmy.world 2 points 1 year ago (2 children)

Then you'd be right back where you started for my purposes, still losing moisture unnecessarily.

[–] Delphia@lemmy.world 10 points 1 year ago (2 children)

I dont care about your purposes, I work in the sun day in, day out. I drink several litres of water and have to go into a hotbox of a portaloo to take a piss. Its like a shit and blue liquid scented sauna and I hate it.

[–] mrbubblesort@kbin.social 5 points 1 year ago (1 children)

That seems more like a workplace problem than a biological one

[–] ivanafterall@kbin.social 5 points 1 year ago* (last edited 1 year ago)

Are you going to tell me how to graft a second urethra down my leg or should I just Google it?

[–] Aussiemandeus@aussie.zone 1 points 1 year ago

Man have i got the solution for you. We call it dehydration.

So the trick is don't drink water get hot as fuck maybe pee once or twice all day.

And as a bonus knock off beers get you hammered

[–] Mac@mander.xyz 2 points 1 year ago

Look up an endurance racing catheter.

No he's asking what if humans had cloacas

[–] Thurkeau@lemmy.world 1 points 1 year ago (1 children)

I can totally see that, though what if the body was able to adapt to the new configuration and keep the gut bacteria in its place, but the urine still flowed into the bowels for reprocessing? What else would the large intestines pick up aside from water and maybe salt?

[–] Rin@lemm.ee 2 points 1 year ago (1 children)

There's not much in urine except water, maybe a little bit of sugar if you're diabetic. I don't think this would be a beneficial adaptation. I'm pretty sure that if this was advantageous, it would have been adapted way earlier in our evolution.

[–] Delphia@lemmy.world -3 points 1 year ago (1 children)

Also girls should pee after sex to flush out the pipes. I can imagine that the works might get clogged up if dudes didnt pee out of the same tube they ejaculate out of.

[–] Shou@lemmy.world 1 points 1 year ago

Not a problem for men to worry about. It is however true for rats. They can get penis plugs because their sperm acts like glue.

[–] Rivalarrival@lemmy.today 26 points 1 year ago* (last edited 1 year ago) (1 children)

Consider, for a second, what would happen if and when the pressure in the colon exceeded the pressure in the bladder, and a urethra connected the two: fluid in the colon would backfeed into the urinary tract. The kidneys would ultimately be exposed to intestinal flora.

The prevalence of UTIs even with the "air gap" of separate waste streams tells me that this would be an extraordinarily bad idea, at least with our current biology.

If we had evolved in a more arid environment, there might be some advantage, but if we had, we would have a significantly different system to maintain homeostasis: it would have to be significantly more resilient to bacterial contamination than our current system.

[–] Chetzemoka@startrek.website 15 points 1 year ago* (last edited 1 year ago)

Can confirm, there is a condition that removes the air gap causing a pretty much continuous UTI. (Colovesical fistula: https://www.medicalnewstoday.com/articles/colovesical-fistula#treatment-and-management)

[–] LackingC10H12N2O@lemmy.world 21 points 1 year ago* (last edited 1 year ago) (1 children)

I have Crohn's disease and therefore already pee out of my a$$ on a regular basis.

0/10 would not recommend.

(obv. not exactly what OP is asking but i imagine it feels the same)

[–] elementalguy2@lemmy.sdf.org 7 points 1 year ago

Ditto. I had my large intestine removed and now adding even more liquid would not be pleasant.

[–] redcalcium@lemmy.institute 19 points 1 year ago (1 children)

Then you'll basically have a cloaca, and perhaps you'll ended up like bird and reptile which can't seem to hold their shit and also have watery shit. One of the great things about mammals is they're able to hold their (relatively) dry shit until they found a safe place to dump it.

[–] Catoblepas@lemmy.blahaj.zone 2 points 1 year ago

That might be a trainability issue rather than a physical capability issue, the more intelligent parrot species are able to be trained to defecate either on command or in specific spots.

[–] Drewdp@lemmy.world 13 points 1 year ago (1 children)

The kidneys already recover water and salt. Google the loop of Henley.

What we pee is what our body considers in excess. We intake a lot of our water from food, so we need a way to expel that. Peeing is much nicer than bloating and constant Diarra.

[–] Thurkeau@lemmy.world 0 points 1 year ago (2 children)

True, though as is, we still need to take in water due to a shortfall in what we do take in. That said, I'm also wondering if my proposal would also result in other waste products being recirculated and building up in the system, causing their own complications.

[–] Zeth0s@lemmy.world 8 points 1 year ago* (last edited 1 year ago)

You are asking for kidney stones. There's a chemical reason you want plenty of water to dilute your waste, that is avoid precipitation

Edit https://en.m.wikipedia.org/wiki/Precipitation_(chemistry)

[–] match@pawb.social 1 points 1 year ago

One waste product building up would be water, in that case

[–] _haha_oh_wow_@sh.itjust.works 12 points 1 year ago

Well, then urine trouble because that would be like having liquid poo all the time. Gross.

[–] BananaTrifleViolin@kbin.social 11 points 1 year ago

So the way evolution works, the design we have works well enough that it doesn't cause problems. It might be the best possible design or it might not, all that mattered is that whenever it arose in evolutionary history it was either an advantage over what camebefore in terms of survival so propagated or it was not detrimental and paired with something else genetically that propagated.

We can't definitively answer your question but we can speculate on why it's a good idea to separate urine and faecal matter. Urine is a reasonable medium for growing bacteria. That wouldn't matter in the colon but would matter if bacteria from the colon could ascend into the kidneys and diarupt it's function. Valves could help or a bladder that drains into the colon, but complete separation may just be better.

It may also be that the acidic nature of urine would disrupt the helpful bacteria we rely on to colonise our guts to help digest foods.

Another possibility is the constant flow of urine would mean our faecal matter would never dry out. It'd be like having diarrhoea all the time and we'd need to poop constantly. The colon retrieves enough water - but not all water - that's why poop isn't hard as rock. If it was flooded with fluid it may not need to retrieve fluid.

The fluid might even be stuck in a cycle between the colon and the kidneys and make it harder for the body to keep homeostasis - as the kidneys excrete more fluid to try and regulate fluid volume the the colon could just resorb it. Basically the colon could end up working against the kidneys and cause even more work for thenl body. It may just be less efficient than discarding water as needed.

Drier faecal matter in the colon and a reservoir of fluid in the bladder does also give us freedom to release when it is safe to do so, which may protect us from predators (having to stop to poop even a few times a day is dangerous compared to only going when you know it's safe to as there are more opportunities to be attacked by a predator). It would also be very easy to track an animal that leaves a constant trail of poop and urine uncontrollably behind it.

All or none of these may be reasons why we have separate urinary and alimentary tracts; it's impossible to know and would always be speculation. But regardless these do seem like reasonable reasons why we may have separate tracts.

[–] jaanus20@lemm.ee 4 points 1 year ago (1 children)

Not a biologist, just a normal dude. Isn't one function of urine to flush out toxins? With them staying in the intestines could it poison the human?

[–] Thurkeau@lemmy.world 2 points 1 year ago (1 children)

That's actually part of my question. The bowels also dump toxins overboard as well, but will they be enough to do the job?

[–] aubertlone@lemmy.world 2 points 1 year ago

I think you need to perhaps watch some videos explaining the anatomy/physiology of the gastrointestinal tract and urinary tract.

The kind of questions you're asking can be easily answered with an understanding of the systems I've stated above.

[–] rufus@discuss.tchncs.de 2 points 1 year ago (1 children)
[–] Thurkeau@lemmy.world 1 points 1 year ago (1 children)

A cloaca still has facilities for urine to be dumped overboard, doesn't it? My proposal is to recirculate it before dumping it overboard dry.

[–] rufus@discuss.tchncs.de 1 points 1 year ago* (last edited 1 year ago)

And what would you do with the water you've taken out in the drying process? Have seperate organs to seperate it (kidneys, colon) and a seperate set of organs to dump it out (pee)? That's returning to the way we humans handle it. Or you need to stop flushing things with the water and stop eating food that contains it. Or your organism just accumulates water and explodes like a water balloon if it has no way to get out. It has to go somewhere if you ingest it.

[–] sagrotan@lemmy.world 1 points 1 year ago

The beargryllneys?

[–] I_Clean_Here@lemmy.world 1 points 1 year ago (1 children)

What if my mother had wheels?

[–] Thurkeau@lemmy.world 6 points 1 year ago

I think that's called a bicycle.

[–] angrystego@lemmy.world 1 points 1 year ago (1 children)

The other solution would be to evolve a bladder capable of reabsorbing water.

[–] Thurkeau@lemmy.world 1 points 1 year ago

That is also something that I have wondered about, but that probably isn't a thing because of salt buildup.