Because fingers and toes are controlled by the autonomic nervous system (also called autonomic nervous system), when the skin is soaked in water for a period of time, the autonomic nervous system will issue instructions to make the subcutaneous tissues of the fingertips and toes contract, and the volume will be correspondingly reduced, while the surface area of the skin remains unchanged, so wrinkles will appear.

Wrinkles on fingers can help people better grasp objects (such as fish) in water, because wrinkled fingers are actually used to drain water to enhance the friction of fingers; Wrinkles on toes can help people walk better in water, because wrinkles are equivalent to the lines of tires, which can make water flow away more easily along gullies, thus forming a negative pressure belt and increasing adhesion.

Extended data scientific verification

The researchers pointed out that the wrinkles on the fingers can make it easier to drain water and increase the friction between the fingers and objects, just like the tire tread. To test this theory, the researchers asked 20 volunteers to soak their fingers in warm water for 30 minutes, which made their fingers wrinkle, and then asked them to move wet glass beads and fishing lead weights from one container to another.

Through experiments, the researchers found that volunteers moved wet glass beads 12% faster than normal when their fingers were wrinkled, but when they moved clean glass beads, the speed was similar. This shows that wrinkling of finger skin can really help people grasp objects better.

Another study found that finger skin wrinkling is the result of contraction of blood vessels under the skin, which is the response of the autonomic nervous system. This is an active process, not a passive reaction after skin absorbs water as previously thought.

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China News Network-Research has found that finger skin wrinkles to better grasp objects.