Among humans, hair takes two to three months to reach its maximum length, while hair develops over two to six years. The strands that make up our hair go through three stages of growth.
The first is anagen, a phase that represents almost the entire useful life of the hair, which is formed in the innermost layers of the skin and continues to grow out of the body at a rate of about 1 centimeter per month.
Then comes catagen, a period in which the thread is at rest and does not grow, this phase lasts a month at most. Finally, comes the telogen phase, which only lasts a few months. That’s when the hair ′′ dies ′′ and falls out, naturally.
The final length of each strand is directly related to its lifetime, which is why hair grows longer than armpit hair and other body regions.
hairy doubts
Find out why the human body has so many different types, colors and shapes of hair.
What parts of the body don’t grow hair?
Lips, palms of hands and soles of feet are regions of the body where there is not the slightest chance of even a little hair being born. And the reason is very simple: while our organism is in formation, even during life inside the uterus, these parts do not develop, under the skin, the necessary structures for the formation of hair.
Why are the wires different colors?
Melanin is the substance that colors hair. However, what defines the tone of the hair is the balance between the two pigments that make up this natural dye. When there is more concentration of eumelanin, the hair is darker. In light or red hair there is a predominance of pheomelanin, a reddish pigment. Albinos and seniors, with total or partial absence of melanin, have white hairs.
What are the types of hair on the human body?
Our capillary mass is divided into two categories: vellus hair and terminal hair. The first encompasses those short and thin strands, which rest discreetly in places such as the forehead and, in the case of women, the neck, face and abdomen. Terminal hair, on the other hand, is the thickest, covering our legs, arms, groin and armpits. Hair on the head also falls into this category.
Why do some hairs only grow on men?
In addition to having more hair than women, men grow hair in areas that are smooth on their bodies – such as the chest, ears or face. This is due to androgenic hormones, such as testosterone, which are produced in greater quantities in furry than in naked ones.
What makes hair straight or curly?
The shape of the hair follicle, where the hair comes out of the body, defines the anatomy of the hair. If the channel is cylindrical, the wire comes out smooth. If it is flattened, the fur is curled. What determines whether the follicle is rounded is its position in relation to the skin. The steeper the slope, the tighter the exit.
How many hairs are there on the human body?
Each individual has about 5 million hairs on their body. The highest capillary concentration is on the head, where about 1 million hairs grow – in those who are hairier, up to four hairs come out of each follicle.
Up to half of this coat covers the scalp on top of the head. The remainder is distributed over eyelashes, eyebrows, inside the nose, beard and ears.
Consultancy: Katleen Conceição, dermatologist, and Ademir Jr., dermatologist and trichologist