What is Hair? Structure and Characteristics of Hair

What is hair? Hair is an appendage of the skin. It offers protection to your body and helps
you look attractive. Hair is mainly composed of a hard chemical substance called Keratin.
It also contains varying amounts of carbon, hydrogen, oxygen, nitrogen, and sulfur.

Recommendable  Products
 
Since we learned about the structure and characteristics of hair,
we should be able to keep it growing and maintain it's good condition.

In the structure of hair, there are two main portions. One above is the surface of the skin and one is below it. The portion of the hair that we are usually most concerned about is called the hair shaft. This is the part of the hair that we see sticking out from the skin. The hair root is the portion that is below the skin.

A variety of structures are connected to the hair root. The hair follicle is a tiny tube-like pit in the skin. At the base of the follicle is the papilla. The papilla is deep in the dermal layer of the skin and is well supplied with blood vessels and nerves. The hair bulb lies just above the papilla and fits over it tightly. The bulb is wide at the base but gradually narrows as it approaches the surface of the skin. The hair bulb is nourished by the papilla.

There are three main hair layers. The outer layer is called the cuticle. This layer is composed of tiny, transparent, overlapping cells resembling the scales of a fish. Beneath the cuticle lies the cortex. This is the main section of the hair, and it is here that we find the pigment granules that give hair its color. When we change the natural color of hair, it is the color granules within the cortex that we change.

The cortex also gives elasticity to hair, and this is the part of the hair that we affect when we style it. The innermost portion of the hair shaft is the medulla. This is a small core of cells that can run the hair bulb to the tip of the shaft. Sometimes the medulla is present only in the part of the hair that is below the skin. The medulla is very scanty in fine hair.

In describing characteristics of hair, we usually speak of its texture, elasticity, porosity, and density. The texture of hair may be coarse, medium, fine or very fine. This is usually determined by the diameter of the hairs. Coarse hairs have a large diameter, whereas very fine hairs have a very small diameter. The hair will retain the same texture throughout adult life until the graying process begins.

At this point, coarse hair may become fine, or fine hair may gradually become coarser. Porosity refers to the ability of the hair to absorb moisture. Elasticity refers to the ability of hair to stretch beyond its normal length and spring back. Normal hair, when wet, can be stretched about one and a half times its normal length. Density refers to the amount of hair per square inch on the scalp. It can be called thin, medium, or thick, depending upon how much hair is there.

By forms of hair, we mean that it is straight, wavy, curly, or kinky. The shape of the individual hair shaft is related to the form of the hair. The shape of the hair shaft in straight hair is usually rounded, wavy hairs are oval, and curly and kinky hairs are usually flat. The follicles of straight hair usually point straight to the surface of the skin. The follicles of the other types of hair are curved. The greatest curve is present in follicles of kinky hair.