There are several hair growth phases, in which your hair grows. These phases together we call the hair growth cycle. It begins when the hair starts growing and ends when the hair falls of your scalp. In this article you can read everything about the origins of the hair, the hair growth cycle, stages of hair growth, hair follicles and hair shafts.
The origin of hair
The hair follicles are often formed in the starting days of your life. By week 22, a developing fetus can have all of its hair follicles active. At this stage there are more than 5 million hair follicles, already active in your body. Around one million of them are on the head, with one hundred thousand of them residing the scalp. This is the largest number of hair follicles that a human will ever have, since we do not generate new hair follicles during the course of our lives.
That is why people that have had chemotherapy or alopecia totalis often can’t grow their hair back. The same happens when you pull your hair off. There will be no chance to grow back any hairs. Most people notice a reduce in the density of the scalp hair, since there do not grow any new follicles.
There are several stages of hair growth, in which your hair grows. These stages of hair growth we call the hair growth cycle. It begins when the hair starts growing and ends when the hair falls of your scalp.
Hair has two distinct structures, the first one is the follicle itself, which resides in the skin and the second is the shaft, which is visible above the scalp. Out of a follicle can grow multiple hairs.
The hair follicle is a tunnel segment and extends down. The structure contains several layers that all have separate functions. At the base of the follicle is a papilla, that contains capillaries and tiny bloods vessels. These vessels nourish the cells and make sure your hair is healthy. The bulb is the living part of the hair and is the bottom of the papilla. The cells of the bulb divide every 23 to 72 hours, remarkably faster than any other cells in the body.
In your hair there is also an sebaceous gland that produces sebum. After puberty the body produces less of this sebum, because as we age we begin to make less sebum.
The hair shaft is made of a hard protein that we call keratin and is made in three layers. The inner layer is the medulla. The second layer is the cortex and the outer layer is the cuticle. The cortex makes up the majority of the hair shaft. The cuticle is a tightly formed structure made of shingle-like overlapping scales. It is both the cortex and medulla that hold the hair’s pigment, which gives it its colour.
The hair growth cycle
Your hair is fed by blood vessels at the base of the follicle, that gives it nourishment. The period between hair growth and hair loss are called stages of hair growth.
Hair on the scalp grows about 3 to 4 mm per day or about 6 inches per year. Unlike other mammals, human hair growth and shedding is random and not seasonal or cyclical. Your hairs can be in three different stages: the anagen, catagen or telogen, if you do not count the fourth phase. The last of the stages of hair growth is called the exogen stage.
Anagen is the first and most active stage of hair growth. The cells in the root of the hair are dividing rapidly. A new hair will form and push the club hair up to the follicle and eventually out of the skin.
During the anagen phase the hair grows about 1 cm every month. The scalp hair stays active in this growth phase and grows for two to six years. Most of your hairs will be in this phase.
Some people have difficulty to grow their hair beyond some certain length because they have a short active phase of growth. On the other hand, people with very long hair have a long and active phase of growth.
It is possible to explain why your arms, legs, eyelashes and eyebrows are so much shorter than scalp hair. This is because they have a short active growth phase. This phase is about 30 to 45 days.
The catagen phase is the transitional stage and the second one of the stages of hair growth. About 3% of all hairs are in the catagen stage at any time in your life. This stage is short and lasts for about two to three weeks. The growth stops and the club hair shrinks.
Telogen is the resting stage and usually has between 6% and 8% of all hairs in this phase. The phase lasts for about 100 days for hairs on the scalp and longer for hairs on the eyebrow, eyelash, arm and leg. In this phase, the hair follicle is completely at rest and the club hair completely forms. Pulling out hairs in this phase will reveal a solid, hard, dry and white material at the root. Each day between 25 and 100 telogen hairs are shed.
The exogen stage is the lastest one of the stages of hair growth. In this stage the hair falls off and new hair develops. If hairs enter the resting stage too early, excess shedding and noticeable thinning of the hair can occur.
You can divide your hair structure in two parts:
1. The structure inside the follicle
2. The structure of the hair shaft that is present above the skin
Structure inside follicle
1. Hair bulb: is the lowest part of your hair strand, which lies inside the follicle. The club-shape of the hair bulb helps to get it locked by the dermal papilla
2. Dermal papilla is the cone-shape elevation that is present at the base of your hair follicle. It fits into the hair bulb and holds it. It is connected in the blood vessels.
3. Arrector pili muscle is an involuntary muscle present at the base of the hair follicle. You get goosebumps when arrector pili contracts.
4. Sebaceous glands are oil glands that are connected to the hair follicles.
Structure inside the hair shaft that is present above the skin
1. Cuticle is the outermost layer of your hair strand. It acts as a protecting layer to the inner hair structure. A strong cuticle layer imparts shine and smoothness to your hair.
2. Cortex is the middle layer of the hair strand. The protein present in the cortex is responsible for the elasticity and colour of your hair.
3. Medulla is the innermost layer in the hair strand. In general, it exists only in thick and coarse hairs.
What can you do to delay hair loss
You can delay your hair growth cycle and hair loss by using products that have an positive effect on the growth of hair:
THE NEOFOLLICS HAIR GROWTH STIMULATING SHAMPOO
The Hair Growth Stimulating Shampoo of Neofollics Hair Technology is a shampoo that has positive effects on the growth of your hair. It stimulates the hair to grow and soothes the scalp. It is effective against dandruff and lays the foundation for healthy hair growth.
THE NEOFOLLICS HAIR GROWTH SUPPORTING TABLETS
The Neofollics Hair Growth Supporting Tablets form an important foundation for healthy hair growth. The effective combination of natural ingredients provide the hair follicles with necessary nutrition to produce healthy hair. These are ingredients such as: saw palmetto, biotin and red clover.
THE NEOFOLLICS HAIR GROWTH STIMULATING LOTION
The Neofollics Hair Growth Stimulating Lotion, is the most powerful lotion on the market to stimulate hair growth. The lotion is suitable for every 18+ man or woman, who wants to effectively improve and stimulate the condition of the hair.
The hair growth cycle consists of three main stages of hair growth. The anagen stage, the catagen stage and the telogen stage. These stages of hair growth are important to understand how hair is growing. During different stages of the hair growth cycle, you can use hair growth products to keep hair in the growth stage longer and encourage it to grow.