Skin is not directly in contact with the outside world: in fact, it is covered with a protective film, which allows skin for the maintaining of its moisture and the preventing of many kinds of aggressions.
Its composition
The cutaneous film on the surface comprises the hydrolipidic film (mainly made of sweat, water, sebum and other lipids), dead cells and microorganisms, also called the cutaneous flora.
Its functions
The cutaneous film on the surface has an antimicrobial effect: due to its acidic pH, it kind of controls the development of microbes. It acts also as a UV radiation-blocker, keeps the hard skin moisturized, prevents skin from many attacks (thanks to amino acids, which maintain the acidic pH), gives epidermis its suppleness, its radiance and makes it pleasant to the touch.
