Hair Fact: Hair grows at approximately 1 cm a month and 6 inches a year.
Hair is made up of a fibrous protein called Keratin which grows from the hair follicle. It may also surprise you to learn that the part of the hair that we display to the world is biologically dead.
Interestingly enough, the hair structure is made up of 3 principle layers, the cuticle, cortex and medulla. Living hair cells are created within the follicle by the papilla, which is a large structure that is situated at the bottom of the hair follicle. The papilla fits around the bulb like a cap, providing vital nourishment to the hair roots. As the new hair cells begin to grow, the older cells die and are pushed along the follicle toward the scalp. The dead cells are compressed together to form Keratin. The hair shaft, which is the hair that we have on show, is keratin emerging from the scalp.
The hair cuticle is a layer of hard overlapping scales which can be between 5-12 layers thick. This layer protects the hair shaft from damage to the inner structure and gives the hair its flexibility.
The cortex is the main component of the hair that is entwined together to form a rope like filament; the centre of the cortex contains long fine threads of spring like chains that bond together. It is these chains that allow the hair to stretch so we can create the fabulous, imaginative hairstyles we all adore. The colour of our hair is also defined by the melanin and pheomelanin, which are the main colour pigments that are placed within the cortex. Melanin in your cortex will determine whether you are a brunette and pheomelanin will determine whether you are a blond or red head.
The medulla is akin to marrow of the hair which resides in the hair’s cavity or the pith of the hair. It is found in the innermost layer of the hair shaft and is only present in large, thick hairs which are more commonly found on your head, as opposed to the hair found on your underarms etc. and consists of round cells which are two to five rows across. Fine hair can lack medulla as doe’s naturally blonde hair. Although the medulla plays a big part in the hair’s structure, its true purpose is yet to be discovered.
Each hair has a very specific life cycle which consists of three stages – anagen, catagen and telogen. The anagen stage is the active growth phase of the hair which can last for up to 7 years. The catagen stage is the transition phase between growth and rest which lasts for roughly 10 days. The hair still continues to grow but at a lesser rate than the anagen stage. Last but not least is the telogen stage, which is the final rest period for the follicle. The hair sheds but the follicle remains for 3 months, and the whole cycle is repeated over again and again.
We each have over 100,000 – 150,000 hairs on our head, and shed between 80 – 100 strands every day. Although these numbers may sound alarming, they are completely normal and typical for a healthy hair life cycle.
To maintain the hair’s natural balance, it is essential to use a good clarifying shampoo to remove product build up that can block pores, and a hydrating conditioner that nourish the roots and provide the essential nutrients to keep damage at bay.