Nails represent dense horn plates on a back surface of the ends of fingers of hands and legs. The nail plate consists of a keratin, i.e. epidermialny cages formed at its basis and zarogovevshy.
Nails perform a number of important functions. They protect trailer phalanxes and fingertips from injuries, are a necessary condition for sensitivity of fingertips, i.e. increase ability of the person to distinguish objects, promoting performance of tactile function.
In ancient times they used for self-defense. In later centuries it was possible to determine differences in human culture by nails, for example, the Chinese tangerines had extremely long nail plates. Presently nails are one of components of human beauty, but they did not lose and the physiological functions.
Often they become an indicator of the disease processes happening in an organism. For example, longitudinal fillets on nail plates demonstrate that their owner has chronic inflammatory diseases (teeth, a nose, a nasopharynx). Cross fillets can indicate diseases of internals (kidneys, a liver, intestines). Existence on a nail of cross grooves says that the organism lacks zinc. It is necessary to be examined also at change of color of nails. So, at blood circulation violation they get a bluish shade. Yellow nails are sign of a sore liver, and emergence on a nail plate of yellowish hillocks can be the certificate of psoriasis. On quality of nails it is possible to judge balance of the consumed food. The lack of nutrients interferes with their normal growth, causes weakness and fragility. In order that nails were beautiful and healthy, vitamins and mineral substances including calcium have to be a part of a daily diet. The insufficient use of animal protein can also lead to deterioration in their state.