Keratin, a strong structural protein, is the building block of human hair, nails and skin’s outer layer. Here we are letting you know the whole process of hair growth. Each hair consists of 3 layers; medulla, cortex and cuticle.
Medulla: The inmost layer of a hair strand is Medulla. It only exist only in the large thick locks.
Cortex: It is the middle layer that is responsible for providing strength, color and texture to the hairs.
Cuticle: Cuticle is the outmost layer of tresses. It is drab and thin and serves for protecting the middle layer, Cortex.
Hair Root’s Structure
Hair root lies underneath the skin surface and is surrounded by a hair follicle. The dermal papilla exists at the foot of these hair follicles. A bloodstream carrying the nutrition that are necessary for the production of new hair, feeds this dermal papilla. In fact the dermal papilla contains receptors for male hormones and androgens that’s why it plays important role in growth of hairs. Androgens control hair growth and sometimes become the cause of hair loss as well.
The Growth Cycle of Hair
Hair growth is cyclical process. Each cycle can be divided into three stages and each hair undergoes all three phases of the cycle.
Phase 1: The first stage of hair growth cycle is Anagen or Growth Phase. It is a proven fact that more or less 85% of the hairs that are present on the scalp are in the Anagen or growth phase at once. Usually, this phase varies from 2-6 years. The approximate maximum growth of curls in one year is 10cm and their length don’t extends over one meter.
Second Phase: Second phase of hair growth cycle is Transitional phase or Catagen. When the first growth phase ends up, the curls enter into the transitional phase which goes on for about 7-15 days. The length of tresses follicles shrink to almost 1/6 of the standard length during this phase. The base tears down and the dermal papilla separates from the base to rest below.
Last Phase: Third and the ultimate phase of hair growth which is called a Resting phase or Telogen follow the catagen. It usually lasts about five to six weeks. Hair stop growing at this stage however, they remain stuck to the follicle whilst the dermal papilla continue resting below.
As soon as the Telogen Phase ends the Anagen Phase restarts. The dermal papilla and the follicle’s reintegrate and in this way the production of new hairs start.