1. YOUR SKIN, NAILS, AND HAIR

2. Healthy Skin Your skin is your body’s largest organ. Your skin performs many important functions. It protects you from germs and helps control your body temperature. Nerve endings in your skin allow you to feel textures, temperatures, pressures, and pain.

3. Parts of the Skin Your skin consists of two main layers. The thinner outer layer of the skin is called the epidermis. The thicker inner layer of the skin is known as the dermis. Melanin consists of cells in the epidermis that give the skin its color. Freckles are spots of melanin. The epidermis continuously makes new skin cells to replace old ones. These new cells are exposed about every four weeks.

4. The dermis has many parts: sweat glands, blood vessels, nerve endings, oil glands, and hair roots. Oil glands keep your skin soft and protect it from cracking and drying. Sweat glands in skin allow perspiration to escape through your pores. Sweat on the skin’s surface cools off, keeping your whole body cool. Water and salts are eliminated from your body through sweat.

5. Pores are tiny openings in the skin. Fat cells are under the dermis.

6. Functions of The Skin 1. Waterproofing. Your skin keeps water out of the body. 2. Vitamin D formation. Your skin uses the sun’s light to produce small amounts of vitamin D, which helps build bones and teeth.

7. Caring for Your Skin Keep your skin clean. Protect your skin from the sun. Ultraviolet (UV) rays from the sun damage your skin. Cover exposed skin with sun-blocking agents or sunscreens with a sun protection factor (SPF) of 15 or higher. Wear protective clothing such as long –sleeved shirts and wide brimmed hats. A dermatologist is a doctor who treats skin disorders.

8. Nails Fingernails and toenails are made of a tough protein called keratin. It makes them hard. The nail plate or body of nail is the actual nail, and is form of a strong flexible material made of several layers of dead, flattened cells. The cuticle is a nonliving band of epidermis.

9. Healthy Hair Hair shafts, the part of the hair you can see, consist of dead protein cells that overlap each other like shingles on a roof. The shape of the shaft determines the overall appearance of your hair: wavy (oval), straight (round), and curly (flat). Your hair color comes from melanin. A common scalp problem is dandruff, flaking of the outer layer of dead skin cells. Head lice cause an itchy scalp. These tiny wingless insects that live in the hair are very common and easy to catch from someone else.