While we’ve spoken about the hair’s growth cycle and how the scalp is an incubator for the hair, we’ve yet to cover what your hair is actually made up of. Equipped with more knowledge about your hair, you’ll be better clued up on how to care for it, so read on for a breakdown of what your hair actually consists of.
What’s your hair made up of?
As you know, your hair grows from a root, which is found at the bottom of the hair follicle. This root is made up of a protein known as keratin, which both your hair and nails are also made up of.
The structure of the hair itself starts with your hair follicle – this is the bit which anchors your hair into the scalp and stops it falling out. It starts at the epidermis (the skin’s top layer) and extends into the dermis (the deeper layer of skin).
Your hair follicles are made up of three parts: the infundibulum, the isthmus, and the inferior segment (lower follicle). Each one also has a sebaceous gland (which produces oil that protects the hair shaft) and very small ribbons of muscle called ‘arrector pili’ that extend from the dermis of the scalp skin to the hair follicle.
At the very base of the hair follicle is a bulb, which contains the follicular matrix – this is where the ‘building blocks’ of your hair are made, where cells reproduce to form the hair shaft. Other cells called melanocytes (which give your hair its colour) are also part of the matrix.
(N.B. This is the ‘living’ part of the hair – where it connects with your scalp. The part that needs a lot of loving care and attention if hair is to grow through healthy, shiny and strong!)
So what about the hair shaft itself? If you cut a strand of hair in half and put the end under a microscope, you’d find it’s made up of several layers. At the middle, its core is called the medulla, which is surrounded by the cortex. This is covered by a layer of cells called the shaft cuticle, followed by three more layers that form the internal root sheath. This is covered by a final layer – the external root sheath, which is what gives hair its shine. While the condition and shine of the hair shaft can be protected with oils and conditioner, the hair itself is already ‘dead’ by this point, so its health or physical structure can’t actually be altered internally. It all starts in the scalp!
Start your scalp and hair health routine as you mean to go on, with our Great Lengths Regime.
Ever wondered about the science behind what makes hair curly or straight? Stay tuned…