Appendises including hair and nails. Derived epithelial hair and horns are formed from modified cells that arise in complex structures, namely follicle located in the deeper layers of the dermis. At the time of hair across the surface of the dermis layer of the hair is covered by sebum excretion from the small glands located adjacent to the hair shaft. Its function is to lubricate the skin and keep skin supple, acts as a water repellent and protect the skin from the dry air.
Nails are made up of cells that undergo modifications horn firmly united. At the proximal nail matrix is formed in the skin. The nail consists of prickle cells that undergo modification in which the nail firmly attached.
Nails that some had the color of blood and some of the pigment melanin in the epidermis, especially. As penitup outer skin has many functions that are not only protective besifat, tetepi also include the following:
It acts as a barrier to infection of origin is in one piece, but can be damaged by microorganisms often excluded by the action of long-chain fatty acids are found in the skin. Invasion of bacteria can also be hindered by the acidity of the skin.
Resilience strong network protects underlying tissues.
Skin acts as an insulator (hipoderm) and helps regulate body temperature. Control of body temperature is also a function of glands and blood vessels sudorifera. When the day is hot, sweat glands menskresi, and evaporation causes cooling; blood vessels dilate to allow the release of body heat by increasing blood flow near the surface of the body. When it is cold, the blood vessels constrict, reducing blood flow and thus reduce heat loss.
Because it contains sensory nerve endings, the sensation of the skin plays an important role in maintaining health.
To a certain extent, the skin acts as an organ of excretion for the body remove waste products. Because it plays a role in maintaining fluid and electrolyte balance.
In appropriate conditions, the skin distribute vitamin D the body. This vitamin is formed by the photochemical action of UV rays on a suspected sterol excreted in sebum.
