There are certain basic facts that everyone knows about the humble hair shaft. For instance, it’s widely understood that hair is made of a special kind of protein, keratin, and that this is produced in a special structure in the scalp called as a follicle. But how well do you really understand your hair, and how it grows? Read on and you may find out some facts that you didn’t know before!
The hair follicle
Hair follicles are tiny indentations in the skin, composed largely of living cells from which the hair itself grows. The surface of the skin, or epidermis, is punctuated by a shaft – known as the root sheath – through which the hair shaft exits the skin. Next to the hair follicle, certain glands can be found, such as sebaceous glands, which are responsible for secreting oils that lubricate the hair, known as sebum.
Beneath this outer layer lie tiny erector pilli muscles, which have the job of raising the hair to create a warm layer of air around the skin, thus preventing heat loss. Deeper within the hair follicle, the hair bulb can be found. This structure consists of the cells responsible for depositing keratin, and the pigment melanin, which is responsible for giving hairs their colour. Receptors for hormones can also be found here, as can arteries that supply the growing hair with oxygen and nutrients.
The hair shaft
Emerging from the pit of each of these follicles is the hair shaft itself. This is composed of dead cells that consist of little more than long keratin fibres and small amounts of water. The three layers of the hair shaft – the medulla, the cortex, and the cuticle – each serve specific purposes, maintaining the structure and colour of the hair shaft in different ways. Because the cells that compose each shaft are dead, it is possible to cut your hair without any pain.
The growth cycle
Hairs do not grow at a constant rate. Instead, they go through stages, each of which is physically distinctive. The first stage, or anagen, is the growing phase, which lasts for 3 to 5 years – about 90% of the overall cycle. After this, the follicle enters a transitional stage – or catagen – where the deeper regions of the follicle begin to collapse. Then the telogen, or resting stage, begins, when the hair follicle goes into stasis. After about 100 days, the hair shaft is shed, and a new anagen begins.
At any given time, 10% of hair follicles are not growing – that is to say, in catagen or telogen. As these hairs are distributed across the scalp no baldness may be visible. However, there are certain conditions that affect this cycle in various ways, which can cause thinning and hair loss. Most conditions that cause hair loss, including the most common cause of hair loss in both men and women, Genetic Hair Loss, will affect the growth cycle progressively and make the hair slightly thinner with each cycle until the hairs are almost invisible.
Applying the science
A scientific understanding of hair follicles and their cycles is of critical importance for the effective assessment and treatment of hair loss conditions. Our experts are well-versed in the biology of hair growth, and the bespoke treatment plans they will produce on your behalf will reflect this. To benefit from their knowledge, simply ring 0800 077 6666 or contact us online to book a no-obligation appointment, or fill in our online diagnostic form, which enables us to put together a home use treatment programme which can be sent directly to your door. We have treated tens of thousands of men and women for a wide variety of different hair loss conditions. View our success stories to see the type of results that can be expected in so many cases.