Biology
Prune Fingers Wrinkles
Quick fact
The wrinkling of fingers and toes in water is triggered by the sympathetic nervous system constricting blood vessels, not by absorption of water into the skin. This response disappears if the nerves to the finger are severed.
Why this is interesting
You've spent a long bath and noticed your fingertips turned into wrinkled prunes. But did you know that this isn't just passive water-swelling—it's actually a clever, active response your body controls?