Hair age and hair length
Question: this week our reader Irina sent a question: "What is the life expectancy of the hair?"
We went to a consultation with the trichologist and received an answer, which we gladly share with you ...
As you know, the hair is a filiform appendageSkin, consisting mainly of solid keratin - protein, as well as pigment, lipids, various microelements and water. Each hair consists of a stem (which is the hair itself) and the root (hair follicle, hair bulb), where the cells are divided and, consequently, hair growth.
The structure of the hair itself includes three layers:
- The inner layer (medulla) is a soft substance, the cells of which are not fully keratinized (keratinized)
- Cortex (cortex) - by volume is up to 90% of the total mass of hair
- Scales of the outer layer (cuticle), consisting of 6-9 layers of cells, which seem to overlap each other like a shingles. With their close fit, the hair will be shiny and beautiful.
The hair grows out of the hair follicle, inWhich places the root of the hair, and the hair follicle feeds itself at the expense of the hair papilla, which brings nutrients to it - it is from it that the growth of hair and their condition depends.
Each hair passes in its development three stages: Stage of growth (2-4 years), rest (15-20 days) and transition from the 1st stage to the 2nd (90-120 days). On average, approximately 93% of the hair is in the 1st stage - the growth stage, 1% - in the 2 nd stage - the resting stage and 6% - in the third, that is, the transition stage.
The quantity, quality, color and structure of our hair are programmed genetically, that is, we inherited from our parents, grandparents, and it is impossible to change this.
The cycle of hair growth repeats during human life 24-25 times. Sometimes it is possible to "wake up" sleeping bulbs, and then you can slightly activate hair growth.</ P>