	Page 37 -- GENDER-RELATED FEATURES OF SKIN

Fingernails

   The nails are flattened, elastic structures which are relics of claws. They consist largely of compressed keratin, and are in fact greatly thickened areas of the epidermis. The keratin of the nails is derived from the stratum lucidum (meaning 'the clear layer'), which lies just below the stratum corneum
(see page 12). The keratin of the nails can absorb large amounts of water, particularly during a warm soak. This is why nails are softer, and much easier to cut, after a bath.
    On average, fingernails grow by half a millimetre or so a week; toenails grow a little more slowly. Growth is said to be quicker in the summer than in winter, and is most rapid in the longer digits.
   The white flecks that sometimes appear in the nails are due to minute air bubbles in their structure. fingernails

Well-cared-for nails enhance beautiful hands.

Gender-related features of skin

   There are subtle differences between the skins of men and women.
  The stratum corneum tends to be thicker in men than in women. Moreover, in men the total skin thickness is about 25% greater than in women. The collagen content of skin is directly related to sex: male forearm skin, for example, contains more collagen than female skin at the same site at all ages.
   There is also a difference in the composition of the sebum. Also, throughout their lives men produce more sebum than women do, and the lipid film on the surface of their skin is therefore more pronounced: as a result, desquamation in men is a slower process than it is in women.
   There are also differences in sweat secretion between the sexes. Men have fewer sweat glands, both eccrine and apocrine.
   Skin aging has different features in men and women. These are discussed in Chapter 4 ('Skin and aging').