What is the structure of human skin? What are the functions of skin and the layers? What is epidermis and dermis?
The skin which covers your body has four main functions.
1. It covers and protects the body from microbes and other harmful materials.
2. It regulates body temperature.
3. It gives off poisons and waste materials by perspiration.
4. It gives you information about the temperature of the air, and the properties of object in contact with the skin (hot, cold, soft, hard, wet, dry etc.)
The skin is made of two layers.
1) The Epidermis : is the outer layer that you see when you look at skin. There are tiny openings (pores) on the surface of the epidermis. The surface of the epidermis is made of dead skin cells. These cells wear off and the dead cells are replaced by new cells produced by the innermost layer of the
2) The Dermis (Inner layer) is the layer of skin below the epidermis. The dermis layer is seen only when the skin is cut. Blood vessels and most nerve endings, hair roots and parts of the sweat and oil glands are in the dermis.
Skin has the ability to repair itself when it is cut. Hair, fingernails and toe nails grow from the skin.
Nerves in the skin allow you to feel heat, cold, pressure and pain. When a hot object touches your skin your nerve endings send a message to the brain. Your brain tells you that you are touching something hot.
The skin covering different parts of your body has different thicknesses. The skin over the eye lids is the thinnest, while the skin on the soles of the feet is the thickest. The number of nerve endings change in different parts of your body. Your face and hands have many nerve endings while your back and legs have a few nerve endings. Would you get more information by, touching something with your hands or with your legs?
In the dermis there are the roots of hair, oil glands and sweat glands. Hairs are made of dead epidermal cells. A hair is rooted in the skin. Oil glands are found in the skin all over the body except the, palms of the hands and the soles of the feet. Oil secreted by the oil glands keeps the skin and hair soft and moist.
Sweat, which helps to control body temperature, is produced in the sweat glands. Hot weather or physical exercise causes the temperature of the body to increase. As a result, a person sweats. The evaporation of sweat has a cooling effect on the body. Sweat is mostly water, but it also contains small amounts of waste product.