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Comment by cityofdelusion | Hacker News Reader

The author suggests humans are overturned to repairing skin and blood, but I strongly disagree. People with problems with wound healing can face significant disability and mortality. Wound healing allows us to have surgery and close up with simple sutures. A lot of complications post-surgery in humans and other animals are specifically from impaired wound healing capability. It’s a good trade-off: nearly everyone will eventually get cut open by accident or on purpose. The skins ability to heal is so amazing that many types of wounds require nothing other than some cleaning, the body will fully clot, bridge, build, and scar back to most retained function. Wound healing allows us to heal large burns and even simply leave many wounds open to air.

Complications with healing are pretty brutal. Necrosis, amputation, infection are all common without the built-in cascade we have.

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I thought the reason was well known, and the article briefly touches it...

The liver's great ability to regenerate largely boils down to how homogenous and simple the liver actually is. It's structured more like a battery pack, where you have individual cells that are largely functionally identical to each other that perform the bulk of the work, and they happen to be connected together. If an individual cell fails, (for the most part) all you need to do is merely regrow a new one, and it's orientation matters little (relatively speaking as compared to other organs) so long as it's connected to the rest of the battery pack (organ).

Contrast that to something like a kidney, which has complex orientation that is formed via growth, and which has a high degree of different types of cells where replacing a part isn't as simple as merely regrowing the part which failed, but also about that growth happening in precisely the right location. So instead of it being like having to replace a failed cell in a battery pack, it's like replacing a wheel to a car. Attaching it anywhere (like the windshield for example) won't necessarily fix the issue, it needs to be connected to the axle...

Also, the liver metabolizes a lot of toxins, and some cells die in the process, so there was a strong pressure to replace them. That pressure was our ancestors insisting on eating toxic things like mushrooms and spoiled food until it didn't immediately kill them.

> our ancestors insisting on eating toxic things like mushrooms and spoiled food

Presumably this didn't happen because are ancestors were dumb, but rather because the ability to process slightly spoiled food is a significant advantage in an environment where fresh food is sometimes scarce?

Our very distant ancestors weren't even human, or biped, so they were indeed quite dumb compared to us; but the sibling comment is right, it was food scarcity. Even us modern humans will eat anything if our survival depends on it.

Another useful evolved ability to eat suspicious things is vomiting. Not all animals can quickly purge toxins that way, cows, horses, or rats, for example.

Yes, the same reason that my dogs will puke something up, and then try to re-eat it.

Survival in the wild is harsh, yo. Try for every scrap of food.

Many problems with would healing are due to nutrient deficiencies. For example, people who are sulfur deficient will heal and recover much slower than those who are not.

That's why so many professional athletes take MSM (Methylsulfonylmethane). Their bodies would not be able to recover as quickly without the extra sulfur.

Huh, another reason to eat more spinach I suppose.

If you like all those carotenoids and oxalates... If rather just have some onions for sulphur instead.

Blanche spinach, try not to eat them raw. Speaking of oxalates, I did not know yam leaves were inedible. Saw a little tender shoot, bit a little piece off. Tastes like mushroom. I don't think it's toxic but it's like eating glass.

Blanching does nothing to oxalic acid.

And that "eating glass" comment is related to how I know. I boiled a wild "edible" (skunkweed leaves) in 3 changes of water; what I should have done is either dry it completely or (better) treat it with lye. Bad memory mistake. Yeah: eating glass shards.

The problem is not wound healing, the problem is over the top inflammatory responses, and yeah with out them injuries could be much worse, but we get a lot of diseases because of accumulated damaged from long term inflammations. Point is doing simple things like eating a bit of sugar spikes your inflammatory reactions, causing all sort of problems down the road.

Ideally we could have a switch, low inflammatory reactions when good, high inflammatory reactions on injuries.

Your liver makes platelets so if your liver function is not optimal, wound healing is harder.

Some people also have rare diseases where they don’t have clotting factors so require a transfusion of clotting factors before surgery for optimal wound healing.

> Your liver makes platelets

Megakaryocytes are primarily bone marrow cells.

Indeed, but your liver does make clotting factors and also thrombopoietin, which stimulates platelet production.

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