ASK A SCIENTIST
Question: What is hair made of?
Answer: We use our hair to express our personalities - to conform, to make a statement, to help us feel good, to attract other people. Our hair even reflects our mood especially when we are sad. Our hair is perhaps our most distinctive feature.
A hair is a specialized outgrowth of part of the skin called the epidermis. It has two distinct parts, the hair follicle and hair shaft. The hair follicle is a tiny cup-shaped pit buried deep in the fat of the scalp. The follicle is the point from which the hair grows. It is well supplied with minute blood vessels, and the blood passing through them nourishes the growing region. The hair bulb lies inside the hair follicle. It is a structure of actively growing cells, which eventually produce the long fine cylinder of a hair. New cells are continuously produced in the lower part of the bulb. As they grow and develop they steadily push the previously formed cells upwards. When the cells reach the upper part of the bulb they begin to change, and they arrange themselves in cylindrical layers, one inside the other. The inner three layers become the actual hair. The outer three layers become the lining of the hair follicle- the inner root sheath. Cells inside the hair bulb produce the pigment that colors the hair - the pigment is called melanin. These special cells are called melanocytes.
Ask a Scientist appears Thursdays. Questions are answered by faculty at Binghamton University. Teachers in the greater Binghamton area who wish to participate in the program are asked to write to Ask A Scientist, c/o Binghamton University, Office of Communications and Marketing, PO Box 6000, Binghamton, NY 13902-6000 or e-mail firstname.lastname@example.org. Check out the Ask a Scientist Web site at askascientist.binghamton.edu. To submit a question, download the submission form(.pdf, 460kb).