The main idea of hair

Your hair grows from follicles within the skin. The hair inside the follicle is known as the hair root. At the base of the hair root is known as the hair bulb, which recieve nutrients and form new cells.
http://www.hairfinder.com/hairquestions/hairgrowth.htm

When your think of the word hair, your probly thinking of your head. But hair isnt just on your head, its many places on your body excluding your lips, soles on your feet, and the palms of your hands. Hair has many different jobs depending on where it is. The hair on your head is used for warmth and little cushion for your skull. The hair on your eyelashes protects the amount of light going into your eyes and the dust going into them. Your eyebrows protect the sweat from dripping into your eyes. The hair you see on all parts of the body contain dead cells, that why when you cut them it doesn't hurt. But if you pull a hair from your body it might hurt because your are pulling out a part of a cell under the skin that isn't dead.
http://kidshealth.org/kid/htbw/hair.html

Chemotheropy drugs get rid of cancer cells that are very quick multiplyers. Other cells in the body like follicle cells multiply fast as well. The drugs cant discern the two therefore attacking healthy cells which cause hair loss.
http://cancer.about.com/od/chemotherapysideeffects/a/preventhairloss.htm

Wigs produced by machines are based on strands that have been woven together with thread. Once the thread has been woven together they are then stitched together in a crosshatch fromation
http://www.ehow.com/facts_5637258_wigs-made-of_.html

Synthetic wigs are made out of wefts of hair that are sewn together to creat the base of the cap.
http://www.womenswigsolutions.com/synthetic-wigs-machine-made-wigs/

Alopecia is the loss of hair from the head or body. There are many different types of this desease.
http://www.alopeciaareatainfo.com/alopecia-areata-types.shtml

Hair loss occurs in middle age men and women. Men and women both respond to think in a negative way. They think it is a loss of physical and mental strength and not looking attractive anymore.
http://www.medicalnewstoday.com/articles/68080.php

The cooling of the scalp is one of the waya to prevent chemotherapy hair loss.
http://annonc.oxfordjournals.org/content/16/3/352.full