Tuesday, 21 May 2019 , 12:41:14

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The hair anatomy

Each hair consists of a root – the part of the hair which is located deep within the skin, and shaft – the part visible on the surface (that which we call our “hair”).

In the hair shaft can be found three concentric layers:

1. Extermal layer, or the cuticle. It is also called outer or scale.

2. The cortex.

3. The medullar layer – the central, inner substance.

The hair anatomyThe medullar substance of hair

This is the central part of the hair shaft, which is not found in all types of human hair. For example, in baby hair the medulla is absent. The medullar substance is replaced by air bubbles, due to which the hair attains some degree of thermal conduction. The medulla plays no role in changing the chemical or physical qualities of the hair.

The hair cuticle

The hair cuticle performs a protective, barrier function. It forms in 6-10 overlapping layers of transparent keratin plates, interconnected by many cross bonds and lipid layers. The cuticle interfaces mechanical and chemical influences on the hair. An undamaged cuticle reflects light well. The hair shines and does not break.

 Core substance (cortex)

Cortex – the main substance of hair (constitutes 70-85% or hair volume) which is made up of thousands of keratin strands. These fibers are twisted between themselves and connected by strong cross links.

Each hair follicle is an independent formation, with its own growth cycle, and these cycles are not synchronized between different follicles. Otherwise, we would lose all our hair at the same time, while in reality this process takes place gradually and unnoticeably.

Each hair follicle has its own nerve system and musculature. Due to muscles and nerve endings, the hair follicle acquires tactile sensitivity, which allows it to complete barely perceptible movements.

You have probably already heard that hair is a nonliving substance, capable of self-regeneration. Living cells, which multiply with great speed, exist in the root of the hair, which is buried deep in the dermis.

The hair follicle is the root of the hair, with its surrounding tissues, which form formations such as exterior and interior root sheets, and the hair-gland complex (sebaceous and apocrine sweat glands, the arrector pili muscle lifting the hair, blood vessels, and nerve endings).

Next «The life cycle of the hair»