Protection: Through the fat cells in the subcutaneous tissue the skin protects the body against blows and falls. The Stratum Corneum acts as a barrier against bacterial invasion. The Stratum Germinativum produces melanin pigment as a natural protection from ultraviolet light.
Regulation: controls our body temperature so that it maintains our internal heat regardless of environmental climate. It does this through the excretion of sweat from the sudoriferous glands, and the dilation of the blood vessels in the dermis.
Sensation: Because the skin contains so many tactile nerve endings, the brain can be made aware of the stimuli of pain, heat, and cold in any part of the body.
Absorption: The skin is able to absorb some oil or fat-based substances on a topical level, but deeper penetration is confined to either medication or application of a water-based substance by means of galvanic current. Penetration of cosmetic preparations is restricted to the epidermal layer only.
Excretion: the eccrine and apocrine glands excrete perspiration and sweat for temperature regulation.
Secretion: Sebum is secreted by the sebaceous glands, and is a complex mixture of lipids and fatty acids. Adult sebum is fungicidal and germicidal and inhibits the growth of skin surface bacteria. Sebum plays an important part in maintaining the surface of the skin intact.
Respiration: To an extent skin cells of the dermis “breathe,” exuding carbon dioxide and eliminating unwanted gasses into their surrounding connective tissue fluid.