Many of us might be wondering why and how our toes and fingers get wrinkly when we stay in the shower or inside the water for a long period of time.
But why can water easily run off our skin when we are washing our hands? Why do our fingers and toes go wrinkly in water but not the other parts of your body?
These are the very basic questions that we asked ourselves as it happens really often in our daily life. Firstly, we all need to know that our skin is covered with its special oil known as sebum.
What is Sebum?
Sebum is an oily and waxy substance that is produced by the sebaceous glands of your body. It is found in the outermost layer of the skin.
Additionally, sebum is a complex mixture of fatty acids, sugars, waxes, and other natural chemicals that form a protective barrier against water evaporation.
Function of Sebum
The function of sebum is to coat, moisturize, lubricate and protect your skin. Sebum is known as the body’s natural oil that makes your skin a bit waterproof.
This explains why water can easily run off our skin when we are washing our hands instead of soaking it up.
However, staying in water for a long period of time eventually washes away the sebum. Result is, water can now penetrate to the outer layer of your skin. After a while, this will cause your skin to become waterlogged.
Why The Other Parts of Your Body Don’t Get Wrinkled?
Actually, some parts of our skin which is known as glabrous skin has a very unique response to water.
In contrast with the other parts of our body, the skin of our fingers, palms, toes, and soles wrinkles after being exposed to wet for a few minutes. It will usually start to wrinkle after being exposed to water for 5 minutes or more.
Scientists used to think that it is the result of a biochemical reaction called osmosis. Many of us have probably learned about osmosis in our science class.
Osmosis is the movement of water through a semi-permeable membrane from a region of high concentration to a region of lower concentration of water.
This process yanks a handful of compounds out of the skin causing the fingers and toes to become pruned. For the longest time ever, everyone thought water was the reason that caused our skin to swell up and get puffy.
A century ago, scientists noticed that this curious reaction was not just a simple reflex or the result of osmosis. Why? Because this does not happen to people with nerve damage either on their fingertips or toes.
Surgeons have also learned that the wrinkling response would disappear if certain nerves to the fingers were cut. Therefore, wrinkled fingers were part of an involuntary or automatic response of the nervous system. Indeed, the wrinkling response has been advised as means of determining whether the sympathetic nervous system is functional in patients that are unresponsive.
More About The Sympathetic Nervous System
The sympathetic nervous system is the system that controls the other fight-or-flight functions that include quickening breathing and slowing digestion.
Furthermore, this system is linked to sweat glands that cover among other areas like your palms and soles of your feet.
Cause of Wrinkly Fingers in The Water
Pruney fingers or toes are actually caused by a process called vasoconstriction. Vasoconstriction is the process when the blood vessels under your skin shrink.
When your nervous system is working properly, soaking in water will send a message through the nerves telling those blood vessels to shrink.
The loss of blood volume will make the arteries, veins and capillaries narrower. At last, the skin over the blood vessels collapses and forms wrinkles.
Wrinkly Finger Improves Your Grip
Here are the reasons why your nervous system want you to have wrinkly fingers in the water.
By having wrinkly surface, it will help you to grip things better. This trait might have benefited our old ancestors digging and working in a wet environment.
In 2011, a team of researchers started to study about the active process of skin wrinkling. They noticed that the folded skin creates a really great drainage system in getting water off the fingertips. They took the test.
Two years later, a second study took the test even further. A team gathers a few participants to pick up both wet and dry objects including marbles with dry hands. Then, repeat the experiment with hands that had been soaked in warm water for 30 minutes. It could be seen clearly that participants could pick up wet objects faster with wrinkly fingers.
On top of everything, this shows that this trait is meant to improve our grip. You can actually try this at home. If you have some marbles at home, try picking them up first with dry fingers. Then followed by your presoaked, wrinkly and pruney fingers. You will immediately notice that your grip has improved as you could pick up the marbles easily and faster with pruney fingers compared to dry fingers.
For your toes, so far no test has been done on it. But when you need to move fast on wet ground or environment, wrinkly toes might have better quality of gripping too. And this might have helped our ancestors a lot in escaping from the predator when it is raining.
If this is such an advantage for us, why don’t humans stay wrinkled at all times? Another group of scientists have tested this theory with other objects too. They said that they did not see any improvement in the ability of gripping. Therefore, the jury will still be out there.
To conclude, the wrinkles on your fingers may give your more grip, just like threads on a car tire. When this happens, leave it as nothing you can do about it. After a while, it will eventually disappear. Lastly, you will be having more sebum on your skin in no time.
Is this answer your curiosity of why do your fingers get wrinkly in water? Share your thought of how fast your finger and toes can get wrinkly after contact directly with water!