HAIR PHYSICAL PROPERTY SCIENCE
What is hair composed of?
Whenever we think of hair, we automatically think of the hair on our head. But hair is actually present in almost all parts of the body. Hair is made up of a protein called keratin which is the same protein in our nails and in the skin.
Hair usually comes out of a root portion called the hair follicle. The average adult head has approximately 100,000 to 150,000 hair follicles. In a normal state about 90% of these hair follicles are active. It is also a fact that hair being all dead cells sheds a certain amount every day. Although various figures for hair shedding are given ranging between 50 and 150, it suffices to say that everyone loses some hair every day and that amount can truly vary from person to person.
Why is it so important to understand that hair is dead tissue?
Both skin and hair are external organs and therefore highly susceptible to environmental and physical stress. In addition, poor nutrition, use of wrong products, internal illnesses and other factors also affect skin and hair. However, because skin is mostly a living, breathing tissue with biologic properties, it has the ability to repair itself and to a large extent, reduce damage. On the other hand, hair is not that forgiving as it does not have biological properties, and thus to a certain extent damage repair is possible if the outer covering or cuticle is intact. However, for most other hair problems, the best way to treat it is to snip off damaged portions and wait for new hair growth. Since hair is attached to the scalp, which is a living tissue, it is important to take care of the scalp, in addition to the hair.
So, what are the different parts of hair?
The hair that we visibly see outside is actually a string of dead keratin cells which is pushed out of the scalp where the living part of our hair the hair follicle is present. The living parts of hair, namely the hair follicle, hair root, root covering, and the oil gland are beneath the scalp skin, and need constant care and nourishment. The actual hair shaft which emerges as visible hair comprises the cuticle or the outermost covering made up of overlapping scales, the outer visible hair strand with the cortex and medulla, and these have has no living processes. Thais is the reason why hair can be cut, pulled into styles, treated chemically and have heat applied with no discomfort at all. So, in a sense hair is like the fabric, while the scalp is like the loom where all the activity happens.