Nails - toe or finger - grow depending on several factors. One of them is the shape and direction of the nailbed: if it’s very curvy, you’ll get more rounded nails (and at the extreme end, ingrowing nails). if it points to a particular direction, the nail will tend to grow following that direction. Think of it as a pasta extruder: the shape of the pasta and the direction it takes when exiting the extruder depends on the hole’s geometry.
Of course, the shape of the bone underneath also guides them this or that way. Nails don’t grow in a vacuum: they’re attached to the digit underneath for most of their length.
After that, nails will shrink depending on how dry the environment is around them. That changes their shape also.
Nails - toe or finger - grow depending on several factors. One of them is the shape and direction of the nailbed: if it’s very curvy, you’ll get more rounded nails (and at the extreme end, ingrowing nails). if it points to a particular direction, the nail will tend to grow following that direction. Think of it as a pasta extruder: the shape of the pasta and the direction it takes when exiting the extruder depends on the hole’s geometry.
Of course, the shape of the bone underneath also guides them this or that way. Nails don’t grow in a vacuum: they’re attached to the digit underneath for most of their length.
After that, nails will shrink depending on how dry the environment is around them. That changes their shape also.