5. How the hair is formed?

The hair is grown from the follicles with the skin and the part that is inside the follicle is called the hair root. The hair bulb is situated at the hair root and is responsible for receiving the nutrients and formation of new cells. The hair that we see protruding from the skin is the hair shaft. It would be better to understand the function of dermal papilla that is found within the hair follicle that is cone shaped. The function of dermal papilla feeds the blood and the nutrients to the hair bulb. The sebaceous gland keeps the hair oily and shiny. The arrector pili are the tiny muscle at the base of the follicle that is sensitive to stimulus like scare, excitement or cold and make the hair stand upright.

The process of hair growth can be explained as follows. Using the nutrients from the dermal papilla the hair bulb is responsible in generating the new hair cells, and moves through the root of the hair and the process of keratinization happens in which the hair is filled with fibrous protein and loses its nucleus. The cell is no longer is alive the moment it loses its nucleus and the hair that protrudes from the skin is merely fiber of keratinized protein. 

6. Hair Growth Cycle

It is better to have a first hand knowledge about the hair growth cycle to appreciate better the reasons for the problems concerned with the hair such as hairless patches and total baldness in both men and in some unfortunate women.

The hair is formed in the hair bulb situated at the root of the hair deep in the hair follicle. It is the hair follicle that is responsible for the production of the hair. The follicle continues to produce hair from the birth of a person until his death. The hair lasts and grows for very longer periods and the same is tortured by shampooing, cut conditioned and exposed to cold and heat and affects only the hair shaft and the hair bulb and the root remain strong. The hair final falls out, leaving the follicle to produce another one after a short break. The process is called the hair cycle.

7. The various stages in the Hair cycle

The hair passes through three different stages namely the growing; the intermediary and the shedding phase each known by distinct names called anagen, Catagen, and telogen. Let us look into these stages.

Anagen (the growing phase)

The growing phase of the hair is known as the Anagen at this stage there is active growth in hair bulb. The stage last for a few years says between three and seven years. The hair grows at this stage without interruption and the normal growth is around I centimeter per month. The growth of the hair also varies according to the season. While in winter the growth is more the same is summer is comparatively less. It is at this stage the hair gets the pigment. But usually the pigment is less in the older people and the hair turns gray but the hair may still be strong in them. In some cases the hair cycle gets shortened in older people and the hair may become thinner and may eventually lead to baldness also.

Catagen and Telogen

Catagen is the second stage in the hair cycle growth that lasts between two and four weeks. The follicle stops producing the hair at this stage, the base of the hair follicle moves upwards to the surface of the skin. The catagen is followed by the telogen that lasts for three to four months. This is followed after the resting period of the follicles when it does not produce any hair and thereafter a new hair begins to grow from the hair follicles. As the new hair grows the old one is naturally shed. The hair at this stage is very weak and may fall out while shampooing or combing. This is a natural process and there is nothing to worry on this phase as usually one in ten hair is shed in this process and new one are grown. The new hair also emerges from the same openings and the cycle repeats.

The hair growth is a natural phenomenon and the nutrients and the health of the hair follicle play an important role in the growth and life of the hair.