Nails are plates from the dead cells of epidermis filled with a keratin, – grow throughout all human life. Their growth happens because the new, not horny yet cages in the lunul push out dead strong cages. In a week the nail can grow by 2 mm.
Growth of nails
Nails are dense horn plates on fingers of legs and hands of the person which are a kind of epidermis. Their appointment is in protecting fingers from damage of soft fabrics and the nervous terminations to them. Nail plates mainly consist of a keratin – one of types of protein which also contains in skin and hair. As a part of a keratin there are many atoms of sulfur which strengthen this substance and do it strong and firm. Except protein, nails contain insignificant amount of water and fat thanks to what the surface of nail plates shines a little.
Also in them there are a phosphorus, calcium, chrome, selenium and zinc.
Nails grow with a speed about 1-2 mm a week, standing slightly more slowly, that is completely the plate is updated approximately for half a year. Various environmental conditions and conditions of a human body can slow down or accelerate growth of nails. Besides, nails grow quicker at women, than at men. In the summer growth increases, decreases in the winter. It is noticed that on a working hand the nails grow slightly quicker, perhaps because blood supply is better for a thicket of the used extremity. If in length the nail can grow as much as necessary, then thickness is defined genetically and to make a plate natural methods of thicker, than is put in genes, it is impossible.
Sometimes nails become thinner because of injuries or the shortage of mineral substances, in that case they can be restored.
Mechanism of growth of nails
The tissue of nails which was dead in it is not present the nervous terminations and blood vessels therefore the person does not feel pain when cuts nails or they break. Nevertheless, horn plates on hands and legs grow in spite of the fact that dead cages cannot share. The fact is that at the basis of nails living cells, in this place they actively are reproduced. Each new living cell gradually is filled with a keratin which thanks to the waterproof properties stops the message of parts of a cage among themselves, and she dies. The horny, dead cell "is literally squeezed out" by the new, recently formed and not filled with a keratin yet cages outside thanks to what the nail plate is gradually extended. New tissue of a nail is formed in a special zone which is called a lunula, it can be seen on each finger, it is a small white or light semicircle in the basis of a nail over which the small layer of skin – a cuticle is formed. It protects the production site of a keratin and new cells of a nail from bacteria and mechanical damages.