Understanding hair structure and growth
Hair is predominately made of keratin and dead skin cells that are anchored into the scalp by hair follicles. These hair follicles form a bulb between the scalp and the strand of hair. The hair follicle produces living cells that divide and grow to build the hair shaft. The hair shaft comprises several layers that each have their own role to play.
There are three hair texture variations that occur in human hair. Each hair texture needs to be cared for differently to maintain strong and healthy hair structure and growth. In this article, we will explain why and how these hair types need to be looked after.
- What’s the structure of human hair?
- Can I improve my hair structure and how?
- How do I know my hair structure?
- How does hair get its colour?
What’s the structure of human hair?
A strand of hair consists of three layers: the cuticle, the cortex, and the medulla. From the outside to the inside of the hair structure, we first have the cuticle layer.
The cuticle layer has scale-like cells which overlap each other on the outer surface of the hair. These cells act as a defence against damage to the inner hair structure.
They also work to control the water content of the hair fibre. The cortex is responsible for the strength, colour, and texture of the hair. While the medulla layer is typically only present in thick hair.
Damage occurs to the hair when the cuticle layer experiences excessive manipulation, chemical over-processing and the over-use of styling tools. Then the cuticle layer becomes damaged and it affects the strength of the hair, resulting in brittle and weak strands. Weak strands are prone to breakage, consequently causing hair loss.
Can I improve my hair structure and how?
When individuals are looking to improve their hair structure, they’re referring to the texture of their hair and it’s thickness. Busy lifestyles, poor diets, and stress mean that hair care is given a backseat in daily beauty routines. Hair texture is improved by taking better care of the hair through:
- A carefully considered diet,
- Reducing the amount of heat used on the hair,
- Using a mild shampoo to remove product and residue build-up
Certain vitamins and oils further improve the texture of hair, including biotin and vitamin C. But hair care needs to be tailored to the hair texture. The hair structure is improved using different methods that depend on the hair texture:
Fine hair: Fine hair is prone to breakage, therefore it needs to be carefully looked after. Anything that further weakens the hair structure needs to be limited, including harsh towel drying. Individuals with thin hair need to dry their hair with a microfibre towel or a soft fabric that absorbs moisture quickly. Rough fabrics damage and open up the cuticle thus causing frizz and breakages.
Medium hair: Medium hair is robust but to maintain its texture it needs to receive adequate moisture. This will strengthen the structure of the hair while also nourishing the scalp.
Thick or coarse hair: Thick hair requires a lot of hydration as it is prone to frizz. Deep conditioning treatments (like olive and coconut oils) soften the hair and make it more manageable.
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Thanks to a unique combination of ingredients your hair receives the essential nutrients that nourish the roots and hair, and prevent their loss. Our shampoos and sprays are highly concentrated biotin, collagen and natural extracts (green tea, red ginseng). In addition unlike ordinary hair care products, ours tackle the problem at the root by cleansing the follicles and strengthening the shaft. Because a stronger and vitalised scalp produces more resistant and, of course, more silky hair!
How do I know my hair structure?
Hair texture/ hair structure has three main categories; the curl pattern, the volume, and the consistency. The curl pattern is divided into straight, wavy, curly or coily hair. The shape of the hair follicle directly affects the curl pattern (oval follicles grow curlier hair).
The consistency of the hair is either fine, medium, or coarse. Fine hair is as thin as sewing thread whereas coarse hair feels thicker, leaving medium hair to fall in between the two. Hair texture can change over time as a result of:
- A loss of collagen: Ageing is coupled with a loss of collagen which affects the hair follicles. This leads to a change in hair texture. The production of natural oils is also reduced with age, resulting in a drier texture to the hair.
- Poor diet: The hair needs sufficient proteins to create a strong integral structure. A diet that ensures that the hair will receive adequate protein and oil will improve the texture of the hair.
- Product build-up: Product residue has a big impact on the hair texture. Residue from products combines with the build-up of dirt and dead skin cells on the surface of the scalp. This causes the hair follicles to become clogged thus changing the texture of the hair as a result.
- Heat damage: Excessive heat (from styling) damages the hair which consequently affects the texture. The hair becomes brittle and dry, resulting in an increase in split-ends and a frizzy hair texture.
How does hair get its colour?
Hair colour is caused by melanin in the hair structure, therefore melanin levels determine the pigment. The levels of eumelanin (a type of melanin) are responsible for black or brown hair, while pheomelanin creates red hair.
Blonde hair is a result of low levels of the dark pigment eumelanin. The yellowish tone of blonde hair is a result of the scarce distribution of pigment. Hair gets its colour through the amount of eumelanin and pheomelanin in the structure:
- Black hair = High levels of eumelanin
- Brown hair = Moderate levels of eumelanin
- Blonde hair = Very little eumelanin
- Red hair = Mainly pheomelanin with a little eumelanin
The crucial role of the MC1R receptor
The best-researched gene that affects the colour of the hair structure is the MC1R gene. Which is responsible for sending signals to initiate the protein production for the melanocortin 1 receptor.
The melanocortin 1 receptor controls the type of melanin produced by the melanocytes (a specialised skin cell that produces melanin). Humans are born with two functioning copies of the MC1R gene, one inherited from each parent.
High levels of pheomelanin create brighter hair
When the MC1R receptor is activated it begins to initiate the creation of eumelanin. But if the receptor isn’t activated or it’s blocked then the melanocytes make pheomelanin instead. The gene is deactivated when a variation has occurred in one of the MC1R copies.
This is described as a “loss-of-function”. When this loss-of-function occurs, the eumelanin production is lower and the pheomelanin production is high. This results in strawberry blonde, auburn or red hair.
Bright red hair is created when both copies of the MC1R gene have a loss-of-function. This causes only the pheomelanin pigment to be produced – for these individuals the hair is typically always red.
Fine, medium and coarse hair needs to be carefully looked after to maintain the integral strength of the hair structure. These different hair textures are composed of the same blueprint structure, but they each need the appropriate hair care regime.
This is needed in order to promote hair growth and work to fight the signs of hair loss. Dr Balwi recommends hair care that’s tailored towards boosting the integral strength of the hair structure.
Serums and shampoos that are specially formulated to effectively battle signs of hair loss are advised for all hair types. They work to strengthen the layers of the hair with their intensive ingredients. Careful hair maintenance is an important part of keeping the hair healthy.