Healthy and Split Nails
Fingernails and toenails are a modified type of hair, and are composed of a very strong protein called keratin.
They serve several purposes, including picking up objects and for defense. Because nails have no nerves, they do not
hurt. However, the tissue under the nails can become quite painful due to pressure.
Keeping the edges of fingernails and toenails smooth by regular use of an emery board 
will help prevent them from splitting.