hair follicle

Taking care of our hair health and preventing alopecia involves having healthy hair follicles. They are like a kind of bag in which the hair grows. If you want to know more about the parts of the hair follicle, how it grows and what its function is, keep reading.

What is a hair follicle?

A hair follicle is a complex, sac-shaped, structure in which hair grows. It is found in the epidermis (outer layer) of the skin. Hair begins to grow at the bottom of the hair follicle, where the root, made up of protein cells, is nourished by blood from nearby blood vessels. The stem grows until it breaches the epidermis.

Where are hair follicles found?

Hair has a simple structure, but it has important functions in the body. It is made up of a tough protein called keratin and a hair follicle that anchors each hair in the skin. 

The hair bulb, where living cells divide and grow to build the hair shaft, forms the base of the hair follicle. Blood vessels feed the cells of the hair bulb and supply hormones that modify the growth and structure of the hair at different stages of life. 

Hair follicles extend from the epidermis to the dermis, entering slightly into the hypodermis, which is a fatty layer just below the skin.

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How are hair follicles formed?

Hair follicles are formed during embryogenesis. It is the result of a series of signals sent between the dermal cells and the superficial epithelial cells causing fate changes in both cell populations. This causes differentiation of the hair shaft, root sheaths, and dermal papilla.

What do hair follicles do?

When hair thins, doesn’t grow, or falls out, the problem is usually with the hair follicles. The overall health of the hair largely depends on the condition of the hair follicles.

As we age, follicles shrink, resulting in increasingly finer, shorter hair, until it reaches a point where new hair is not produced and the follicle dies and scars. When that happens, the only way to get your hair back again is with a hair transplant.

If hair weakening and loss are noticed in the initial phase, treatments for alopecia such as Minoxidil can be prescribed. Minoxidil is a vasodilator that stimulates hair follicles by providing a greater amount of blood flow. This can delay hair loss and promote regrowth.

There is also the option of treatment with Dutasteride, an antiandrogen that has been shown to be effective against hair loss since it prevents the hair from losing quality due to the action of male hormones. In addition, Platelet Rich Plasma (PRP) combined with hair mesotherapy works to nourish and stimulate the follicles in the areas affected by alopecia. 

It must be taken into account that, if folliculitis on the scalp is not treated correctly, the follicles may end up being damaged. Luckily, this common inflammatory condition is easy to treat.

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Hair follicle anatomy

The hair follicle is a complex structure that makes up the hair root. The stem of the hair grows towards the epidermis. The hair follicle can be divided into the following parts:

  • Hair bulb. It is embedded in the deepest part of the dermis and is the germ of the hair. In it, we find the follicular papilla, composed of melanocytes, melanosomes, stem cells and capillaries responsible for hair nutrition.
  • Sebaceous glands. Their job is to lubricate and protect the hair with the grease they continuously produce. They are stimulated by androgens and inhibited by estrogens.
  • Arrector pili muscle. Also called the piloerector, it is a small, involuntary muscle with smooth fibres found in the dermis. It ensures that the hair grows perpendicular to the skin and not attached to it, like vellus hair.
  • Sheaths. There’s an external one, which surrounds the hair follicle, and an internal one, which separates the hair shaft from the external sheath.

There are also dermal papillae in the outermost layer of the superficial dermis. In this layer, there is a vascular plexus that is responsible for transporting oxygen and nutrients through various capillaries. This ensures proper hair growth.

Hair follicle cycle

The growth cycle of the hair follicle has three phases in which periods of growth (anagen) alternate with periods where the hair falls out (telogen). The passage from one to the other is known as the catagen phase.

Anagen phase

The anagen phase is the hair’s active phase. The hair root cells divide rapidly. A new hair is formed, pushing hair that has stopped growing or is no longer in the anagen phase up the follicle and out of the head. During this phase, the hair grows approximately 1 cm every 28 days.

Catagen phase

The catagen phase is a transitional stage and about 3% of all hairs are in this phase at any one time. This phase lasts between two and three weeks. Growth stops and the outer root sheath shrinks and sticks to the hair root. 

Telogen phase

This is the resting phase and usually represents between 6% and 8% of all hair. It lasts about 100 days for scalp hair and longer for eyebrow, eyelash, arm and leg hair. During this phase, the hair follicle is completely at rest and the hair is fully formed.

What is the role of hair follicles in hair health?

Hair follicles not only play a key role in hair growth but also contain glands that produce and release a type of natural oil called sebum. Therefore, healthy hair follicles are essential for having a good head of hair, but also for healthy, smooth skin.

The role of hair follicles in hair loss

When hair weakens, does not grow or falls out, there is usually a problem with the follicles or their nutrition. So it can be said that optimal hair health depends, to a large extent, on the good condition of the hair follicles. 

How can hair follicles be strengthened?

Although there is no way to avoid genetic and age-related factors, there are daily routines that can be carried out to keep hair in the anagen (active) phase for as long as possible. These are some of the best routines for strengthening hair follicles:

Massage your scalp:

By incorporating regular scalp massages into your routine you can help restore hair growth, stimulate the bulbs that nourish the strands, and promote the overall health and well-being of the roots. 

Scalp massages can improve hair thickness and growth but are also great for relieving stress and tension. You can use just your hands and maybe hair oil to complement this routine. 

Avoid chemical treatments:

Dyeing your dark hair grey may seem like a great makeover idea, but too strong a chemical treatment definitely does not help natural hair growth or care for the hair follicle. In fact, it weakens it. If you want your hair to be as long as possible, try to avoid aggressive treatments.

Brush your hair:

Do you know why it is so important to brush your hair often? Because doing so is the most effective way to distribute natural oils and maintain healthy moisture. In addition, brushing improves circulation, which helps to make the scalp healthier.

However, it is important to remember not to brush your hair while it is wet since wet hair is in its most fragile state. And of course, never pull to untangle knotted hair, as it could break.

Avoid heat:

Styling tools with high temperatures damage your hair, causing it to break and go frizzy. If you can’t give up this habit, at least try lowering the temperature and applying a heat protectant first.

Rinse with cold water:

High temperatures are just as damaging to hair as they are to skin, so whenever possible, rinse your hair with cold water to help seal and strengthen the cuticle before styling.

Vitamin B6 and folic acid:

Finally, eating foods like rye, rice, wheat and oats is very good for your hair health because they have a high content of vitamin B6 and folic acid, essential for oxygenating the blood in the hair follicles.

If you are concerned about your hair health or have begun to notice that your hair is no longer the same as always, contact Insparya to make an appointment. Our specialists will answer all your questions, identify the causes of your hair problem and offer you the best solution.