The Hair Structure

Hair Structure

Hair on their structure is divided into the barrel (visible above the skin surface of the hair) and root (of hair, which is located in the dermis at the root of the vagina). The root and root sheath together form a hair follicle. Trunk or the hair shaft at an angle to the skin surface, while the angle can vary from 10 to 90 degrees (the smaller the angle, the harder it is given installation, but also a high probability of inflammation of the scalp as a result of ingrown hair).

Within the hair shaft is the medulla, cortex and secondary cuticle. Medulla is not completely dead cells, cortical substance - it's dead skin cells, which are pigments responsible for light hair (eumelanin or phaeomelanin). Zumelanin responsible for black-and-brown color, and pheomelanin in the yellow-red. In different proportions of these pigments give hair a certain color: brown, black, blond, red, gray and ashy, and their different shades. The cuticle consists of several layers of cells that resemble scales, are directed away from the hair root to the center.

As for the hair follicle (also known as onion), this is the most important part of the hair, as it is at the root of the hair cells are located, which strenuously sharing, form the hair itself, as well as many blood vessels that provide nutrition hair. By the bulb adjacent dermal papilla, which contains blood vessels and is responsible for monitoring the status and growth of hair? Papilla is extremely important throughout the hair system, because without it, the hair dies (in this case if the nipple remains even when ejection of hair from the root, it will ensure the growth of new hair.) By the hair follicle papilla but also adjacent sebaceous glands (glands of up to 200 000, and the amount produced by fat 50g), sweat glands, as well as the elevator. Sebaceous glands may depend on many factors: the power phase of the menstrual cycle, sex, age, and so on. The sebaceous glands are very important, because using them on the skin creates a water-lipid film, which is protective. This film is composed of dead epidermis cells, sebum and sweat glands and has a slightly acidic medium (which prevents the growth of microorganisms). Plus, this film has a water-repellent effect, prevents drying of the epidermis and protects against harmful UV rays. Above all in the hair follicle contains many nerve fibers that extend from the bulb to the epidermis. To save the water-lipid film, strongly recommended that you use to wash the usual alkaline soap (preferably liquid preferred), and if you do use it, thoroughly rinse it with the skin surface.

hair follicle

Among the main parameters of hair is to provide the length, thickness, elasticity and porosity. On average, hair grows 1 cm per month (it falls every day 40-80 of hair). The length and thickness of hair depends primarily on the race (very long, thick and coarse hair with representatives of the Mongoloid race). The thickness also depends on age: for example, neonatal hair 3 times thinner than adults, and in old age, hair thins again. Plus, the thickness of the hair also depends on hair color: very thick red hair and blondes have the thinnest. Good elasticity of hair guarantees the possibility of the hair to stretch up to 30% of its own length and return to its original condition, and good porosity helps retain moisture in up to 50% of body weight.
Hair goes through several stages: anagen (growth period), telogen (resting period) and catagen (the period of transition from one stage to another, thus there is atrophy of the follicular papilla, resulting in hair follicle cells stop dividing and undergo cornification). In general, healthy people, about 80-90% of hair is in anagen phase, 1-2% - in stage catagen, and about 10-15% - in the telogen phase.

Author:

Dr. Adrina Barack

Resources:

Wikipedia

Hair Structure and Chemistry Simplified By John Halal

Published Date: 16.09.2011