Читать книгу The Face Lift Massage: Rejuvenate Your Skin and Reduce Fine Lines and Wrinkles - Narendra Mehta - Страница 12

The skin covers virtually the entire body, providing a barrier that protects the underlying tissues from dehydration, friction, physical and chemical damage, and invasion by harmful organisms. The skin is relatively waterproof, although some moisture is absorbed when you take a bath – this causes the skin to swell, producing the wrinkling we notice after a long soak. The skin also contains sebaceous glands that produce an oily substance called sebum. This keeps the skin supple and lubricated and helps protect against moisture loss. The skin still loses some moisture, however, especially in the dry atmosphere of a modern centrally heated home or office, which is why you should apply moisturizer regularly to keep the skin supple. Sweat glands have an important defensive role, too. Sweat is slightly acidic and combines with sebum to produce a protective layer called the acid mantle that guards against bacteria and fungi. Sweat also contains an enzyme, lysozyme, that can destroy bacteria. In response to sunlight, some skin cells produce a dark-brown pigment, melanin, which blocks damaging ultraviolet radiation.