Figure 16.8: The structure of fingernails is similar to toenails. Thefree edgeis the part of
the nail that extends past the finger, beyond the nail plate. Thenail plateis what we think
of when we say “nail,” the hard portion made of the tough protein keratin. Thelunulais
the crescent shaped whitish area of the nail bed. Thecuticleis the fold of skin at the end of
the nail. ( 16 )
Figure 16.9: Hair, hair follicle, and oil glands. The oil, called sebum, helps to prevent water
loss from the skin. ( 14 )