why do our fingers look pruny after being in water for an ex

Solution

Absorption of water by keratin causes the purning. If you noticed, only the parts of the skin with of dead keratin like pads of the finger tips will purne. The stratum carnium of the pads of the fingers is very thick and have a lot of keratin in it thus it absorbs more water causing it to wrinkle. If you take a file and file your finger tip pads, you will notice less purning compared to soak in water.