Question: how does hair grow

Sarah Martin answered on 19 Jun 2012:

Hi nadiasoares!

Great question! Hair is made of old cells and a protein called keratin, and that’s produced in little pockets in our skin called follicles.
It’s grown in three steps:
The anagen phase is known as the growth phase. It can last up to eight years. The span at which the hair remains in this stage of growth is determined by genetics. The longer the hair stays in the anagen phase, the faster and longer it will grow. During this phase, the cells in the follicle divide to produce new hair fibres. About 85% of the hairs on one’s head are in the anagen phase at any given time.
The Catagen phase: Signals sent out by the body determine when the anagen phase ends and the catagen phase begins. The catagen phase, also known as the transitional phase, allows the follicle to renew itself. During this time, which lasts about two weeks, the hair follicle shrinks and the hair strand is cut off from its nourishing blood supply.
During the telogen phase the hair and follicle remain dormant anywhere from 1–4 months. Ten to fifteen percent of the hairs on one’s head are in this phase of growth in any given time. The anagen phase begins again once the telogen phase is complete. The preceding hair strand is pushed up and out by the new, growing strand. The process causes the normal hair loss known as shedding.

Enough information?
🙂 Sarah