October 8, 2010

Hair 101: the basics

We’re going back to basics today!

Before we get in to more technical aspects of hair care, you have to know the basics. Once you have the basics covered, then you’ll be able to understand why certain products, styling tools, and etc. work!

First things first, let’s talk about your hair SHAPE.  I’m not talking overall appearance and shape of your hairSTYLE, but the actual shape of the individual hairs on your head.

hair follicle shapes

Your hair shape is determined by your hair follicle

A hair follicle that is round in diameter is going to produce hairs that fall straight. An oval shaped hair follicle is going to produce waves or curls, which will be determined by the roundness of the follicle.  (More round, less curl. More flat, more curl) A flat or elliptical hair follicle is going to produce the curliest hairs.

The easiest way to display this property is by taking a hair off your own head. Pinch one end of the strand of hair, and with your other hand, pull the hair through your pinched fingers. The hair will now be curly, because you changed its shape.

The hair follicle also determines the texture and density of your hair; a bigger hair follicle means you have thicker hairs, while a smaller follicle means you have thinner hairs. Please understand, this is not the same thing as having thin or thick hair!

The hair strands themselves are comprised of three layers: the medulla, the cortex, and the cuticle.

hair follicle cross section

The medulla is the innermost layer of the hair, think of it as the marrow of your hair. NOT ALL HAIRS have the medulla layer. Very light blondes, and those with very thin hairs often times will not have a medulla at all.

The next layer is the cortex. This is the layer that holds the pigmentation for your hair. This layer gives your hair strength, elasticity, and tenacity. It is this layer that changes when you use chemicals on your hair.

The third layer is the cuticle layer. The cuticle layer is made up of many, many transparent, overlapping scales.  It’s primary function is to protect the cortex layer.  Healthy hair has a very smooth cuticle layer, which means your hair will be soft and shiny. Damaged hair has a rough cuticle layer, and would have to be repaired with different conditioning treatments, depending on WHY the hair is damaged.

Damaged hair will not repair itself. Your hair is DEAD, otherwise, it would hurt when you cut it off. Your hair follicle is alive, which is why it hurts when you pull a hair out, but once the hair grows above the skin, it is no longer alive.