Skincare Knowledge ❘ Momotanijuntenkan

Skin Structure

Skin structure

Skin Functions

Protective function	Human skin works to absorb external impacts and prevent various kinds of chemical substances or microbes contained in wind, dust and the outside environment from entering the body.
Perceptual function	Human skin has a touch spot, which gives a feeling of touch, and warm and cold spots, which give a feeling of warm or cold, from which a signal is transmitted along the nerve to the brain, where the stimuli are received.
Body temperature adjustment function	Human skin works to regulate body temperature. When the body becomes hot, the skin cools the body by sweat. When the body becomes cold, the skin develops goose bumps and warms the body by generating heat.
Secretion function	The skin works to secrete sweat made in sweat glands and secrete sebum made in sebaceous glands.
Absorptive function	The skin works to absorb substances through the epidermal route (stratum corneum) and the hair follicle route (pores).
Skin turnover	The skin works to create new skin cells to replace existing cornified cells on the surface layer of the skin.

Skin Turnover

From among skin functions, turnover is most closely related to beauty care. Cornified cells on the surface layer of the skin are originally generated in the basal layer and gradually come up to the surface, through the spinous layer and the granular layer, to become cornified cells at the cornified layer. For a full cycle of takeover, it takes a total of 28 days: 14 days to come to the cornified layer, and another 14 days to become cornified cells and be exfoliated as scurf. When skin turnover functions well, the skin surface can be kept in good condition. Once this cycle is disrupted, skin condition will get worse, leading to skin trouble.

Moisture Balance in the Skin

Moisture balance in the skin is maintained mainly by water from sweat, secrete sebum made in sebaceous glands, natural moisturizing factors of corneocytes, and intercellular lipid. As with those of the skin, major ingredients of skincare lotions are water, oil, moisturizing factor, and intercellular lipid-similar factor. These ingredients keep a good balance of moisture in the skin, creating the same moisturizing environment as that the skin naturally has.