en
Livros
Karen Gilbert

Natural Beauty

  • towokiffez uma citaçãohá 6 anos
    Understanding the skin

    The dermis

    This layer is quite tough with a lot of elasticity since it is mainly composed of connective tissue made up of collagen and elastin. As we age, the collagen fibers—which help to bind water to the skin and give it strength—decline, and so wrinkles start to develop. If the skin is overstretched, as in cases of obesity and pregnancy, the elastin fibers can rupture, resulting in stretch marks. The dermis also contains hair follicles, sweat glands, sebaceous glands, blood and lymph vessels, and sensory nerve endings.

    The sebaceous glands are located near the hair follicles and are present in all parts of the body except the palms of the hands and soles of the feet. They secrete sebum—a mixture of oils and fats—in order to keep the skin lubricated and to provide some waterproof protection. Sebum also acts as a bactericidal and antifungicidal agent to prevent microbes invading the skin. Sebaceous activity is regulated by the male sex hormone androgen, which is present in both men and women and increases at the onset of puberty; this is why oilier skin and acne are more common around that age, especially in teenage boys.

    The epidermis

    The outermost layer of the skin is itself made up of several layers. The basal layer, at the bottom, also known as the stratum germinativum, is where new cells are created. During their 40-day cycle, the cells move gradually from the basal layer through to the stratum corneum at the surface, where they are sloughed off in a process called “desquamation.” New cells will then take their place, and the cycle starts again.

    The basal layer is also the site of melanocytes, which are responsible for pigmentation in the skin—the production of melanin. Melanin production is actually your body’s defence mechanism against the harmful rays of the sun.

    SKIN TYPES

    NORMAL

    If you are lucky enough to have neither particularly dry nor oily skin, then it could be classed as normal and just needs to be kept clean and hydrated with simple cleansing and light lotions. Many skins fall into what is known as the combination category. Combination skin is where the “T zone” of forehead, nose, and chin is slightly oilier than the cheeks. The cheeks are not necessarily dry, but most of us produce more sebum in the center of the face. Don’t be afraid to treat each area with different products, if necessary. If you always seem to have a shiny nose, don’t use any moisturizer on it since it is obviously producing plenty of oil on its own.

    OILY

    Although more prone to blocked pores and blemishes than dry skin, oily skins do have the bonus of looking younger for longer. However, they can also be prone to dehydration and sensitivity, so take that into account when choosing your skincare. Avoid any ingredients that are heavily occlusive, since they may cause breakouts,
fb2epub
Arraste e solte seus arquivos (não mais do que 5 por vez)