Читать книгу Good Skin - Ingrid Wood - Страница 9

The dermis is composed entirely of living cells. While the epidermis can repair itself, the dermis can become permanently damaged. This layer consists mainly of collagen, a protein that’s responsible for the structural support (i.e. strength and resilience) of the skin. Collagen is packaged in bundles held together by elastic fibres. These are made up of another protein, elastin, which gives the skin its tone, plumpness and elasticity. Also found in the dermis are the sebaceous glands, hair follicles and sweat glands. The main function of sweat glands is to regulate the body’s temperature. They are distributed over the entire body surface, with a larger number on the palms, soles and forehead. The sebaceous glands produce sebum (oil), the skin’s natural lubricant. They are very sensitive to hormones, especially male hormones, which increase the glands’ size and the secretion of sebum. (That’s why males are more prone to acne, especially during puberty.) Sebaceous glands therefore play a key role in determining facial skin type.

MELANOSOME COMPLEXES

Do men and women age differently?

There is definitely a difference in male and female skin and so also in the ageing process. Women have less collagen than men to begin with, and because men have a thicker stratum corneum and produce more sebum than women, the lipid film on their skin surface is more pronounced. Furthermore, men’s sebaceous glands are active well into their eighties. Also, testosterone, which is found in far higher levels in men, increases the rate of cell turnover in the basal layer and enhances collagen production, thereby thickening the skin. While there is a gradual thinning of skin with age in men (about 1% per year), the thickness of a woman’s skin remains fairly consistent until menopause, when her oestrogen levels start to fall. Then she will experience a dramatic thinning of the skin, and decreased collagen synthesis and repair. In addition, there is an increase in intrinsic ageing with the failure of oestrogen production and reduced dermal hydration.