Understanding Hair

The more a woman knows and understands her hair the better her hair will look. The more knowledgeable she is about what makes her hair feel right, the more she will grow to love it, or at least that’s my theory. It worked for me; I am hoping that a better understanding of your hair can work for you too.

Understanding black hair is not rocket science but it is hair science and that is something that all black women should be familiar with because no one else will know your hair like you. No hairdresser, no hair blogger, no scientist or chemist or doctor or the old lady down the road or even your own mother knows your hair like you do. You are the boss of your own head of hair and that’s why you need to know the basics.

Even the basic knowledge about what to do with your hair and the science behind it, can make a world of difference to your hair regimen and how you treat your hair. Armed with the proper information you can blow all the hair myths and bad practices to smithereens, to emerge with fabulous black hair.

Which means there is no good reason to get frustrated with your own hair. You just need to understand it. So if you are concerned that your hair is taking too long to grow or doesn’t grow at all or you have more bad hair days than good. Read on.

What is Hair?

The word “hair” usually refers to two distinct structures, the place beneath the skin, called the hair follicle or when pulled from the skin, hair bulb. And, the shaft—which is the hard part (the strand, the visible part that we run our hands through) that extends above the skin surface.

Hair Anatomy

Each strand of hair is made up of the and cuticle, cortex and medulla:

The cuticle, is the outer layer of the hair and consists of several layers of flat, thin cells overlapping one another, under a microscope it resembles fish scales or shingles on a roof. When your hair cuticle is not lying flat and snug and looking smooth and seamless, you will have a problem.

Diagram of cuticle

The cortex is the middle layer of the hair and the thickest part of the hair it is the primary source of mechanical strength; it contains keratin which is protein. It is also the place that contains the hair pigment, giving hair its color. This layer is responsible for the overall strength, and stretch of the hair. The cortex is the place that needs to be opened up in order to add color, if you are changing hair colors. If you are applying a relaxer the cuticle opens to the cortex, thus changing your hair curl pattern breaking the keratin bonds in your hair.

Cuticle-Medula-Cortex

The innermost region, of the hair shaft is the medulla. It takes up a small space in human hair. The medulla’s presence in human hair differs from person to person and from strand to strand on a single person’s head. One hair may have an absent medulla while another from the same person may have a complete or fragmented medulla.

The Shape and Texture of The Hair

The shape of the follicle determines the shape of the cortex, and the shape of the fiber is related to how straight or curly the hair is. Scientists have come to believe that the shape of the hair shaft has an effect on the curliness of an individual’s hair. People with straight hair have round hair fibers. People with curly hair have a flatter hair fiber.

Whilst the shape of the follicle determines how curly or straight your hair is, the size of the follicle determines how thick your hair will be. In curly hair, the hair follicle can form an elliptical or ribbon-like shape, and sometimes an oval shape with flattened hair follicles.

The follicles enable the hair strand to form tight curls or coils which make it difficult for oils, produced by the sebaceous glands, to travel down the hair shaft. The lack of oil causes the hair strands to become dry which is the reason curly or kinky hair needs constant moisture.

 Hair-Position-and-Structure

The Volume of Hair

An individual’s hair volume can be thin, normal, or thick. This trait is determined by the hair follicle volume and the condition of the strand. Fine hair has a small circumference in relation to medium and course strands. Coarse hair has the largest circumference. Coarse hair has a more open cuticle than thin or medium hair causing it to be the most porous.

Fine hair strands have a thin smooth consistency, whereas coarse hair possesses a harder more wiry consistency. Medium hair strands are neither fine nor coarse and fall in the middle of the two consistencies.

The Sebaceous Gland

The sebaceous glands are microscopic exocrine glands in the skin that secrete an oily, waxy odorless secretion, called sebum; it lubricates and waterproofs the skin and hair.

The purpose of the sebum is to:

Waterproof and lubricate the hair and prevents it from dying.

In hot conditions, sebum delays dehydration by producing a barrier to prevent excess sweat.

In colder conditions, sebum becomes more fatty, creating a lipid that coats the hair and skin to repel water.

Sebum may act as a delivery system for antioxidants, antimicrobial lipids, pheromones,

Sebaceous glands are an integral part of hair care. If there is a malfunction in the glands various hair issues can occur.

The Hair Follicle

The hair follicle is where hair growth takes place. It is the only living part of the hair. The visible hair that we see has no life and is considered dead. Please see How To Have A Healthy Hair Scalp for more details on this.

Hair Growth

Hair grows at an average of six inches per year; this is true whether you are black, white or Indian. Black hair (kinky curly hair) is only perceived as growing slower because unlike Caucasian hair types, the hair texture is more susceptible to breakage and shrinkage.

Hair follows a specific growth cycle with three distinct and concurrent phases: anagen, catagen, and telogen phases.

Each hair growth phase has specific characteristics that determine the length of the hair. All three hair growth phases can occur simultaneously; one strand of hair may be in the anagen phase, while another is in the telogen phase.

In the anagen or active phase, the cells in the root divide to form new hairs pushing the bulbs of the old ones out of the scalp. This cycle can continue from to two to six years, in some cases ten.

In the catagen or transitional phase, growth stops and the outer layer of the hair root withers or shrinks, wrapping around the root to form a bulb.

In the telogen phase, the bulb forms completely and some shedding might occur. This occurs naturally, so shedding is nothing to be afraid of within reason.

 So Does This Mean That Your Hair Can Grow?

Definitely. Every woman’s hair with exception of those persons who may have medical problems will go through these phases.

Your hair will reach a certain point depending on what is called your ‘terminal’ length, which is the anagen phase of hair growth (for some people two to ten years).

Some persons have no concept of how long their anagen phase of hair growth might be, it might be longer than you may think if you give your hair the proper care.

Just think, if your average growth phase in the anagen stage is five years, calculating that you lose or cut an inch or two off your hair every year you can achieve 25 inches of hair length if you treat your body and hair right. When you consider it, that is quite a bit of hair length and it can be achieved though with carefully studying what works or what doesn’t work for your hair type of hair.

Please see Hair Types for a classification on the types of hair.

 

Sources:

http://dermatology.about.com/cs/hairanatomy/a/hairbiology_2.htm

http://www.merckmanuals.com/home/skin_disorders/biology_of_the_skin/structure_and_function_of_the_skin.html

Biophysics of Human Hair, Biological and Medical Physics, Biomedical Engineering 2010, pp 1-19

6 Comments »

  • Amber said:

    Soaking up this info…contemplating my start date to taking action.

  • Melanie Goodman said:

    Very Informative. I love learning about the science behind the hair. I was a biology major so I really enjoyed how you broke hair growth down to a science.

  • A'Jia Jackson said:

    I love science and I love you for sharing your knowledge of hair. Thank you or Namaste.

  • Natacha Adams said:

    Hi Brenda, after reading a few of your articles, I’ve decided to mix of few oil up. I mixed Shea butter with Jamaican coconut oil, vitamin E and lavender oil. It’s been 3 weeks now, but my hair is shedding a lot. I’ve never had that problem before. However, everyone is telling me how healthy my hair is looking lately. Could you, please, help me understand this dilemma.

Add your comment

You can also subscribe to these comments via RSS.