- Function of skin

The abnormal stratum corneum causes many skin troubles. If horny layer is damaged due to some reasons, epidermal cells will be exposed to external environment. Hence skin will become vulnerable to desiccation and external infection.

Skin is the multi-functional organ. At first, skin has body protecting functions. Skin protects internal organs from external environment. It not only blocks viruses, UV, and harmful substances such as pollutants but also recovers damaged cells. Sebum is secreted from sebaceous glands to form sebum membrane on the skin surface. It plays a key role in protecting body by avoiding the excessive water loss, absorbing the external shock and healing the wounds.

Second, skin has respiration and excretion functions. 1% of the total oxygen respiration occurs through skin. If you put on make-up too thick or for a long time, it will affect the skin's breathing and hence it will be unfavorable to the health of the skin. Additionally, the skin excretes sweat and metabolic waste through the sweat glands and sebaceous glands to assist metabolism and remove pollutants which penetrate into the skin.

Third, skin has thermoregulations functions. Skin is the major organ that controls heat from environment. It detects heat in the environment, and the brain determines whether the detected heat is too much, suitable, or not enough for the body to function appropriately. If the environment is too hot, the skin sweats to release body heat by the evaporation sweats. Moreover, it dilates capillaries near the skin so that they can release heat which brings color to the cheek.

Finally, skin has cognitive functions of external environment and reactions. Nerves are distributed in the skin to detect external environment changes. The primary functions of the skin are sense of pain, touch, pressures and so on. Sense of nerve endings receptor is evenly distributed throughout the skin therefore it can deliver information to brain to plan next reaction under the changed environment by detecting pain, hot, cold, soft and rough feelings.