On average, 100 thousand hair follicles are found on the head of each person. Of these, about 20-30 hairs can grow during life. Moreover, each of them is a unique substance, the structure of which is very interesting and unusual.
Hair structure and structure: informative video
Sometimes the hair is called dead. Moreover, scientists are still arguing whether such a name can be used in relation to hair or not. This is due to the fact that the physiological properties of the hair that a person sees cannot be called fully alive. After all, the vessels supplying it with blood do not fit to it, there are no nerve endings, and, of course, the hair outside is in no way connected with the muscles.
Thanks to this, when cutting hair, a person does not experience pain, blood does not appear anywhere, and muscles do not stretch with banal combing
But, despite all this, hair is more often referred to as living substances, since it has the ability to reproduce itself. It’s just that all living cells are usually located at the root.
Scientists claim that each hairline consists of two parts – permanent and temporary. The hair follicle is one of the permanent ones, due to which the hair grows. The hair itself, which is outside, is called temporary. Hair grows due to cell division in the follicle, more precisely, in its lower part – the bulb. Due to the fact that it is located in the lower part of the follicle, the bulb is close to the blood vessels, which feed it and also supply oxygen.
Sebaceous glands are also usually located near the blood vessels, so that the hair is closely associated with them. Namely, sebum is responsible for the shine of the hair.
Hair buds are laid in a person at the time of intrauterine development (this happens in the third month of pregnancy). The hair follicle is located quite deep inside, in the fatty layer of the skin. At the same time, despite the fact that its size is negligible, it consists of different formations (the number of which is quite large). This is a thin fibrous capsule, and a vitreous membrane, and an external root sheath, and matrix cells, as well as a bulb, a funnel and many others. Each of these elements have their own distinct functions. So, for example, the cells of the matrix at the moment of active division give rise to hair, the funnel is the place where the hair goes out, the root sheath covers the growing hair and is its full support and protection against early hair loss.
According to its chemical composition, hair is a mixture of various useful elements in the following percentage:
- 15% water
- 78% protein kerotine
- 6% lines
- 1% pigment
Keratin is a substance that strengthens hair (and the main part of its composition is amino acids). Moreover, the body spends a large amount of energy to produce a sufficient amount of this protein.
If a person experiences any disruptions in the work of the body, for example, nutrition worsens, the sleep schedule gets lost, the working rhythm changes, all this directly affects the hair: they slow down their growth, become dull, brittle and begin to actively fall out
The structure of the hair consists of three layers. The outer one is called the cuticle (it is also called the integumentary layer or scaly). Its functions are quite simple in nature and complex in execution. The cuticle is the protection of the hair. By its structure, it consists of several layers (from 6 to 10) of thin keratin plates. Such plates are usually interconnected rather closely with the help of cross-links and lipid layers. It is the cuticle that protects the hair from mechanical damage and the harmful effects of atmospheric phenomena.
Normally, the cuticle should reflect light well, while the hair, with a healthy cuticle, looks shiny, shiny and not brittle.
The middle layer in the hair structure is the cortex. This is usually called the main substance of the hair, which occupies about 85% of the volume of the entire hair shaft. The cortex consists of keratin fibers, the number of which is more than a million. As a rule, they are all securely twisted together and additionally secured with cross ties. It is in the cortex that melanin is contained, which gives hair color. Melanin is produced by special cells called melanocytes. If these cells malfunction, the amount of coloring pigment fades away, and the hair turns gray.
The inner layer of the hair is called the brain. Despite such an unambiguous name, the medulla is not necessarily present in the hair. So, for example, based on the following classification, this substance is not present in vellus hair. Anyway, medulla mostly have only long hair. The medulla itself (also called the medulla) is air bubbles in the hair shaft. At the same time, it does not carry any special physical or chemical properties.
How many hairs there will be, how abundantly they will cover the head and how actively they will grow can be traced and analyzed according to the stages of hair growth.
The growth stage (scientifically called anagen) lasts 3–7 years (depending on the living conditions of a person, the state of his body and many other factors). On average, scientists have calculated that hair grows by 1 cm per month. In women, hair grows longer and faster. So, for example, in men, the anagen stage for each hair lasts 2 years, in women – 5.
The next inevitable stage is catagen (called withering)
By itself, it is very short and only lasts a couple of months. Sometimes it goes away in a few weeks.
The transitional stage is replaced by rest – telogen. At this moment, the hair freezes – it no longer grows, but it still does not fall out. This phase lasts about 3 months. Then the hair will fall out, and another from the same follicle grows in its place. All these cycles, according to research, can be repeated about 15 times in a person’s life.