Skin is the largest organ of the
integumentary system made up of
multiple layers of epithelial tissues
that guard underlying muscles and
organs.
Skin pigmentation varies among
populations, and skin type can range
from dry skin to oily skin.
Severely damaged skin will try to
heal by forming scar tissue, often
giving rise to discoloration and
depigmentation of the skin.
integumentary system made up of
multiple layers of epithelial tissues
that guard underlying muscles and
organs.
Skin pigmentation varies among
populations, and skin type can range
from dry skin to oily skin.
Severely damaged skin will try to
heal by forming scar tissue, often
giving rise to discoloration and
depigmentation of the skin.
Skin performs the following functions:
 | Protection: an anatomical barrier between the internal and external environment in bodily defense; | |
| Langerhans cells in the skin are part of the adaptive immune system | ||
| Sensation: contains a variety of nerve endings that react to heat and cold, touch, pressure, vibration, | |
| and tissue injury. | ||
| Heat regulation: the skin contains a blood supply far greater than its requirements which allows | |
| precise control of energy loss by radiation, convection and conduction. Dilated blood vessels increase perfusion and heat loss while constricted vessels greatly reduce cutaneous blood flow and conserve heat. | ||
| Control of evaporation: the skin provides a relatively dry and impermeable barrier to fluid loss. | |
| Loss of this function contributes to the massive fluid loss in burns. | ||
| Aesthetics and communication: others see our skin and can assess our mood, physical state and | |
| attractiveness. | ||
| Storage and synthesis: acts as a storage center for lipids and water, as well as a means of | |
| synthesis of vitamin D by action of UV on certain parts of the skin. | ||
| Excretion: sweat contains urea, however its concentration is 1/130th that of urine, hence excretion | |
| by sweating is at most a secondary function to temperature regulation. | ||
| Absorption: Oxygen, nitrogen and carbon dioxide can diffuse into the epidermis in small amounts, | |
| some animals using their skin for their sole respiration organ. In addition, medicine can be administered through the skin, by ointments or by means of adhesive patch, such as the nicotine patch or iontophoresis. The skin is an important site of transport in many other organisms. |
Skin Care
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