Friday, November 18, 2016

Additional Structure In Human Skin

Structure of Human Nails

Nails are derivatives of the epidermis, in the form of slabs horn substance found on the dorsal surface of the fingers and toes. Nails are composed of the roots and part of the body.
Seen from above, the nail body proximal end there is a section called white crescent-shaped lunula. Nails are hard slab above the last knuckle. Each - each nail attached to the corium which are modified into a matrix / base of the nail.
At the end of the nail bed is a fold of skin in which there is the nail root. Elongated nail growth caused by the division of cells in the stratum soft germ at the root of the nail.

Hair Structure People

Hair is a thin layer of horned derived from epithelial invagination of the epidermis. Color and size varies according to race, age sex, and area of ​​the body. Hair is almost contained in the whole body except on the surface of the hand.
Hair grows in a discontinuous and have a period of growth followed by periods of rest. This growth does not occur simultaneously in all parts of the body, although in the same area. This type of growth is called a mosaic growth.
Long periods of growth and rest periods are not equal to the area of ​​the body. Hair growth on body areas such as the scalp, face and pubic greatly influenced by hormones - sex hormones (specifically androgens), adrenal and thyroid hormones. Hair growth is not affected by how often a haircut or shave.
Hair wrapped by the hair follicle, which is an invagination of the epidermis which occurred during the period of growth with a widening end called the hair bulb. Part of the hair inside the hair follicle called the hair root.
Hair is formed by mitotic cell-cell germinal epithelial food sufficiency in the hair bulb. The germ cells will continue to divide and experience diferiensiasi into cells that form the hair medulla, cortex hair, and the hair cuticle. Cells that are older are urged away from the area of ​​growth, the cells are dead and keratinized, forming part of the enlarged base of the hair.
The hair is contained in the hair follicle called the hair root, and that extends to the outside / surface of the skin called the hair shaft. Hair consists of, cuticle, cortex, medulla. Medulla is the innermost layer of cells which often includes the air space.
Fine hair covers the whole body except the soles of the feet, palms, knuckles and last. Hair has no blood vessels, nutrients derived from the blood vessels in the corium papillae.

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