It grows because of the division and multiplication of a type of cell, the keratinocytes. They are located in the hair bulb, a region of small structures within the skin where the strands develop, the so-called hair follicles. “As the keratinocytes divide, they are pushed upwards, causing the hair to grow”, says dermatologist Valcinir Bedin, president of the Brazilian Society for Hair Studies. The life cycle of our mane’s hair has three phases: birth, growth/resting and shedding. Each of the approximately 5 million hair follicles you have on your head can repeat this complete cycle up to 20 times over your lifetime. But of course they work at different paces. That’s why, at this very moment, you have strands that are being born, others growing and so on. As the number of follicles is absurd, the amount of them in the fall phase is also large. Result: a young person loses approximately 100 hairs a day! This is normal. Worrying is when that number increases a lot, which can be the sign of a ghost that scares men: baldness. Boys whose father is bald are great candidates to follow the same path, as the problem is hereditary. But there are still cases of hair loss due to illness or serious emotional distress – that story that so-and-so went bald out of concern is not so much… Women, despite not being the main victims of baldness, can also face periods of hair loss exaggerated, as in the postpartum period. The concern with this type of problem is more than natural, since hair is an important symbol of beauty. And even because of this, the most diverse myths emerged on the subject. From the most curious (and less hygienic) ones, such as “you shouldn’t wash your hair frequently to prevent it from falling out”, to the ones followed strictly by women, such as “you have to trim it to grow it”. The two, by the way, are just popular beliefs.
dive into it
At the bookshop:
Living Well With… Your Hair, Valcinir Bedin and Denise Steiner, Kalys, 1999
On the Internet:
https://science.howstuffworks.com/hair-replacement1.htm
https://www.hairtoday.com
From side to side
Even if you don’t cut your hair all your life, it will hardly reach your feet. Because of the useful life cycle, the longest length a wire usually reaches is 1 meter. Of course, there are exceptions, like the record holders in giant hair, who have strands with an abnormal survival time.
Busy life
Each strand lives about six years. There are up to five years in the birth phase, a few weeks in the growth/resting phase and a few more months preparing for the fall. Growth of about 1 cm per month occurs from the root (which is in the hair follicle) to the tip. Because it is sensitive to light, hair grows faster during the day and in the summer and continues to grow for up to 24 hours after the person dies.
by a thread
Baldness is hereditary and genetically determined. But it doesn’t always mean total hair loss. Often, what doctors call miniaturization of the follicles occurs: that is, these structures decrease in size, leaving the hairs thinner. Eventually the follicles may die, but this is not a rule.
hit the skin
Dandruff, that kind of white «bran» that spreads over some heads, is a flaking of the scalp. It doesn’t look good to see her tracks, but, apart from the aesthetic aspect, she doesn’t cause major damage. Dandruff can arise from genetic, emotional and environmental factors. A more radical version of the scalp problem is psoriasis, which forms a reddish plaque covered with scales.
Like that
What determines the type of hair – oily, dry, normal or mixed (oily root and dry tip) – is the amount of fat produced by the sebaceous glands connected to the hair follicles. The greater the production of the glands, the more oily the wires will be. Each type requires specific shampoos and care products
passing blank
Over time, the cells that manufacture melanin lose their production capacity and the hair begins to turn gray. This, in general, occurs around the age of 30 and the first area to have gray hairs is usually the side of the head. But there is an “advantage” to gray hair: as the space previously occupied by melanin is filled with air bubbles, the strands are born very strong.
From light to dark
Hair color is determined by the protein melanin, produced by cells in hair follicles. The greater the amount of melanin, the darker the hair will be. Children usually have lighter strands because melanin production only increases in adolescence, encouraged by the sex hormones of that period.
Hair shape is genetically determined and largely depends on where the hair follicles are located under the scalp. See what the main differences are:
Straight:
The follicles have a very vertical position and generate round hairs (if analyzed under a microscope)
Wavy:
The follicles are a little more inclined than those with straight hair and generate oval hairs.
Curly:
The follicles are in a position almost parallel to the scalp and generate flat hairs.