Is Your Hair Stronger Than Steel?: Questions About Hair, Skin, and Teeth
Why do we need skin and hair Your outer wrapping of skin hair teeth and nails does a lot more than keep up appearances Between them they protect you from damage or infection and keep you at the right temperature You can become seriously ill if you get too hot or too cold Your skin acts as a blanket against the cold and allows heat to escape when you’re hot Are all hairs the same thickness Generally speaking East Asian people have thicker individual hairs than people from other parts of the world 4
Is your hair stronger than steel An object of around 3 ounces 100 g could dangle on a single strand of human hair That’s nearly two regular-sized bars of soap It’s not quite as strong as steel but it’s up there with other strong substances like Kevlar used to make bulletproof vests Bacteria yuck Why do hairs really stand on end Your body hairs lie flat when you’re hot and rise when you’re cold to trap a warming blanket of air How does skin protect you from germs Think about all the germs in the air and on the things you touch Your skin shields your organs and major systems from the illnesses that those germs can cause Just a small break in your skin can provide an opening for infection That’s why your body works quickly to form a scab over a cut It plugs the hole so that new skin can grow 5
SKIN THICKEST Thinnest skin How thick is your skin It differs in thickness around your body The thickest skin is on the soles of your feet and is around 0 16 inch 4 mm thick Your eyelids are made of some of your thinnest skin only 0 02 inch 0 5 mm thick Your skin does lots of different jobs from protecting and insulating your body to giving you the sense of touch Is skin really an organ Yes the largest of the body’s organs Laid flat a 13-year-old’s skin would cover around 18 square feet 1 7 sq m about the size of a twin bed 6
How does skin work It is divided into layers The part that you can see called the epidermis is the outside layer It forms the protective barrier for your body The layer beneath is the dermis which contains blood vessels sweat glands and hair follicles The bottom layer called the hypodermis connects your skin with your muscles Yikes How much dead skin comes off Every minute you lose 30,000 to 40,000 dead cells from the surface of your skin Dermis Sweat gland Epidermis Hypodermis Hair follicle Blood vessel Are we really covered by dead skin The skin that you see is made up of dead skin cells New cells are constantly forming at the base of the epidermis They then begin the journey upward Older cells nearer the surface die and rise to the surface as these new cells replace them 7
