It's no secret that training for a doctor is a habitual and obligatory process. Every day there are new research results, important discoveries and new products in the pharmaceutical market. Continuing education of a doctor – this is the key to the successful treatment of his patients, and one of the issues that any specialist must master to perfection – it is the anatomy and physiology of the organ or organ system that he treats. The state of health and pathology of hair – this is the main subject of study of the science of trichology. On estet-portal.com you will find a simple, understandable and absolutely reliable answer from a medical point of view to the question: where does hair grow from.
How does human hair grow from a medical point of view
There is hair on the body of almost every living being. As you know, in the animal world, hairline performs one of the most important functions – protective, and therefore the bodies of animals are almost completely covered with hairs.
A distinctive feature of human hair is that it grows only on certain areas of the skin. Moreover, the hair in the armpit – it is a trait unique to humans.
Sometimes you can hear the erroneous opinion that human hair – it is a dead substance. Yes, we really do not feel pain when the hair is cut, break or fall out, and we do not feel discomfort during any manipulations with them. But at the root of each hair there are living cells that multiply, being deep in the dermis, from where, in fact, human hair grows.
Where hair grows from:
- where hair grows from: hair anatomy;
- where hair grows from: hair physiology.
Where does hair grow from: hair anatomy
From the point of view of the anatomy of human hair, it is divided into two fundamentally important parts: the shaft and the root. The shaft or trunk is that part of the hair that is located above the surface of the skin, and consists of:
- medulla – cells that are not completely keratinized;
- cortical substance – keratinized cells, which make up 90% of the total mass of the hair;
- cuticles – the outer layer of the hair.
The hair root is located in the dermis and is surrounded by a root sheath, together with which it is called the hair follicle. It is a thickening, consisting, for the most part, of cells that are actively dividing and forming, in fact, hair – it is the matrix of the hair follicle. In the lower part, the hair or dermal papilla adjoins the bulb, which contains blood vessels. It is thanks to the dermal papilla that hair grows: if it dies – the hair also dies, but if the hair is uprooted and the papilla remains – a new hair will grow in its place.
Where does hair grow from: hair physiology
How hair grows in terms of physiology – this is the most important question, without having an answer to which, a specialist will not be able to cure any trichological pathology. & nbsp; In its development, the hair follicle goes through several phases:
- catagen phase – lasts several weeks, is characterized by atrophy of the hair papilla, as a result of which the cells of the hair follicle are deprived of nutrition, stop dividing and undergo keratinization. It is generally accepted that the first hair cycle begins with this phase;
- telogen phase – This is the dormant period of the hair, when the cells of the bulb seem to rest. The telogen phase lasts only a few months, passing into the anagen phase;
- Anagen phase – This is the period of hair growth, which lasts an average of 3-6 years. It is during the anagen phase that the cells of the hair bulb matrix actively divide, allowing the hair to grow. With age, the anagen phase tends to decrease.
Typically, in a healthy person, about 80-90% of the hair is in the anagen stage, 10-15% is in the telogen stage, and only 1-2% is in the catagen stage.
Thus, the answer to the question "where does the hair grow from" lies in the anatomical features of their structure and physiological features of functioning. Human hair grows from the dermis, where their matrix is located – actively dividing cells, and the hair papilla, which provides nutrition to these cells.
Dear colleagues! On June 24-26, 2016 Georgia will host the main event of the year in the world of trichology – 17th Congress European Hair Research Society (EHRS 2016).
You will be able to take part in the social program, as well as meet old friends and make new ones. We hope that your participation in this scientific forum will provide a lot of new, professional information.
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