why do fingernails seem to sharpen as they grow?



First post, so I hope I am doing this right!

I have noticed that when you trim your nails, the profile of the nail’s edge is pretty much squared off, but as the nail grows it seems to sharpen. Could this be due to simple wear and tear, do different layers of the nail grow at different rates, or is it something else?

For clarification, I am not talking about a top view of the nail. I am talking about the perspective of the end of the nail as viewed from the side.

In: Biology

it thins out due to daily tasks wearing them down. just like you mentioned in your post. this is also why nails are more likely to break the longer they grow

It’s wear and tear. Imagine that side profile of the nail after you cut it. It looks mostly square, right? So, what part is going to wear away first? The corners. The center of the profile can’t possibly wear away first because how would it even come in contact with stuff to wear it down?

Over time the edges wear away and you’re left with a sharper nail than when you first cut it.