Wrinkly fingers
Wrinkly fingers have long been an indicator that it's time get out of the bath. But why do our fingers and toes wrinkle during a bath?
Scientists think that they have the answer to why the skin on human fingers and toes shrivels up like an old prune when we soak in the bath. Laboratory tests confirmed a theory that wrinkly fingers improve our grip on wet or submerged objects, working to channel away the water like the rain treads in car tires.
People often assume that wrinkling is the result of water passing into the outer layer of the skin and making it swell up. But researchers have known since the 1930s that the effect does not occur when there is nerve damage in the fingers. This points to the change being an involuntary reaction by the body's autonomic nervous system — the system that also controls breathing, heart rate and perspiration. In fact, the distinctive wrinkling is caused by blood vessels constricting below the skin.
In 2011, Mark Changizi, an evolutionary neurobiologist at 2AI Labs in Boise, Idaho, and his colleagues, suggested that wrinkling, being an active process, must have an evolutionary function. The team also showed that the pattern of wrinkling appeared to be optimized for providing a drainage network that improved grip. But until now, there was no proof that wrinkly fingers did in fact offer an advantage.
In the latest study, participants picked up wet or dry objects including marbles of different sizes with normal hands or with fingers wrinkled after soaking in warm water for 30 minutes. The subjects were faster at picking up wet marbles with wrinkled fingers than with dry ones, but wrinkles made no difference for moving dry objects.
Read more:
http://www.nature.com/news/science-gets-a-grip-on-wrinkly-fingers-1.12175
Photo credit Lucien Dubois
Interesting...
ReplyDeletePerhaps still not convinced, but nice article. ○~♡
My entire life I thought our fingers wrinkled because the oils got washed away... this theory is refreshing in a way. I've never thought of it like that
ReplyDeleteWow!
ReplyDeleteAnother indication that we come from the water.
ReplyDeleteHmmm... Interesting! I always thought that #skin #wrinkling was due to dehydration.
ReplyDeleteIs this not to do with Osmosis, the net movement of water from a high water potential to a low water potential? Doesn't this cause the cells to become either crenated or turgid (haemolysis) ?
ReplyDeleteDewi, could be. That's why I questioned the post.
ReplyDeleteIt's much more complicated, with the sodium, osmotic pressure, etc. needing to be factored in.
Cynthia Bush ahhh OK. That makes sense. That's interesting though. Do you think its relating to osmosis or the theory above?
ReplyDeleteI don't think osmosis has anything to do with this.
ReplyDeleteWater-induced wrinkles don't form on the tips of previously severed but subsequently reattached fingers, which means wrinkles are instead produced by nerves that automatically trigger constriction of the blood vessels beneath the skin, reducing the volume of the tissues there.
Another hypothesis I've heard is when you soak fingers in warm water, the blood vessels tighten and the flesh of the finger shrinks to a greater extent than the skin. Hence: wrinkling. But let's not forget that pruning happens in cold water also, which doesn't tighten blood vessels.
This is an interesting post with much conjecture. I will return later to comment further.
ReplyDeleteActually my own correction, this couldn't be Osmosis because dead skin cells are keratinised therefore meaning they are made of insoluble proteins of which water will not flow through and excretment. Maybe it's simple diffusion through the dead skin cells. Your hypothesis number 1 seems a perfectly valid explanation.
ReplyDelete