Know your hair

The hair is one of the most important factors which contribute to beauty and personal appearance. For its proper care, it is essential to have a basic knowledge of its structure. The hair is made up pf keratin, a protein based substance. This substance also forms finger and toe nails. Each hair consists of three layers. the central core, known as medulla, is made up of spongy tissues which may contain some colour pigment. The middle layer, known as the cortex, consists of long thin cells which give the hair its elasticity and colour. The outer layer, known as cuticle, consists of hundreds of tiny, overlapping scales.

Hair is formed in minute pockets in the skin, called follicles. An upgrowth at the base of the follicles, called the papilla, actually produces hair, while a special group of cells turns amino acids into keratin. The rate of production of these protein "building blocks" determines hair growth. The average growth rate is about 1.2cm ]per month, growing fastest on women between the ages 15 and 30 years. The sebaceous gland which secrets the oil that gives healthy hair its natural shine is located half way along hair follicle.

The follicles, which contain the hair roots, are fed by blood carrying nutrients. Good circulation is thus of utmost importance to healthy hair. It is th supply of nutrients which determine[s the health of hair as it emerges from thescalp and continues to grow. Once hair leaves the follicle, it is in fact technicially "dead", but it grows because of continued tissue formation within the follicle.
The disturbance in the production of sebum by these glands can result in over dry or greasy hair. Thus, if the glands become blocked or are underactive, the hair will be greasy.

The natural colur of hair and its hape straight or curly are determined by hereditary factors. In case of curly hair, the actual shape of the hair follicle forces the emerging hair to develop waves. The number of individual hairs ranges between 90,000 to 140,000, depending on the natural hair colour. Blondes the most hair since their hair is thinner than of brunettes. Redheads have the least number of hairs, although theirs will often look more abundant since it is generally the sickest. The number of hair roots or the texture of the hair, canot be changed except the natural changes which occur with age.

The life-span of a hair varies from several months to several years, depending on the scalp and hair conditions. The average life of a hair is five years. After that, the follicle from which the hair is growing begins to shrink and the hair remains static untill is drops out or is brushed out and is replaced a few months later by a new hair. Although a large numbr of hairs may come out in a single day, it will not does not from in the follicle due to inadequate blood supply, or glandular or hormonal imbalance.

There are four types of hair-normal, greasy, dry and greasy-dry. Normal hair is shiny yet not greasy, and fairly easy manage. Greasy hair looks good for a day or two after shampooing but then quickly bcomes lank. Dry hair is difficult to control after shampooing, looks dull and nds that are dry and split. Greasy-dry hair is usually fairly along and the hair nearest the scalp is greasy while the ends are dry.