The Biology, Structure, and Function of Hair

Table Of Content

• Stages of hair growth
• What are the three stages of the hair growth cycle?
• Gradual thinning on top of the head
• 2 Middle Anagen Stage

After rapidly building the hair equivalent of a skyscraper in anagen and capping supply lines in catagen, the exhausted follicle now takes a break. This relative period of inactivity lasting 2-3 months is called the telogen phase. Studies show specialized structures called dermal papillae at the base emit signals like FGF5 to stop hair matrix cells from multiplying. The hair shaft also hardens and attaches more firmly to the follicle.

Stages of hair growth

There is a myth that a sudden shock can turn your hair white, but as the follicles of hair are already dead, there is no medical reason for your hair to change color. Like every evil villain, it does it with the help of a sidekick, an enzyme called 5α-reductase. This means that DHT can’t get that boost it needs to miniaturize your hair follicles. This final stage of the cycle is when strands start to crowd your hairbrush or fall onto your favorite sweater.

What are the three stages of the hair growth cycle?

This type of baldness is genetically inspired and occurs in the presence of the converted androgen di-hydro-testosterone. ‘Greying’ of hair is due to the gradual loss of the melanocytes’ pigment – melanin. This is largely determined by heredity factors, hyperthyroidism and some autoimmune diseases. The structure of hair follicles is simple and straightforward, but its functions and its growth cycle are quite complex.

Apoptotic cells may drive cell death in hair follicles during regression cycle - Phys.org

Apoptotic cells may drive cell death in hair follicles during regression cycle.

Posted: Mon, 23 Oct 2023 07:00:00 GMT [source]

Gradual thinning on top of the head

This can be triggered by conditions such as nutritional and medical situations, illness or stress. For instance 6 weeks after intensive dieting or stress you can experience hair fal. This occurs because the growing stage (Anagen) is cut short and hairs enter the falling (Telogen) stage at the same time. Adding a mask to your arsenal is a surefire way to arm your hair with the nutrients needed to remain strong and healthy.

This occurs when your anagen (growth) phase is cut short, and many hairs enter the telogen (resting) phase at the same time – resulting in increased hair fall 3 months later during the exogen (shedding) phase. At the end of the growth phase, the hair root separates from the papilla. Then a transitional phase called the catagen phase starts, lasting about two to four weeks. When the hair has separated completely from the papilla, the supply of blood is cut off in the final resting phase, which is also called the telogen phase.

During this chapter, hair follicles shrink and hair growth slows. The hair also separates from the bottom of the hair follicle, yet remains in place during its final days of growing. Hair loss, hair thinning and problems with hairgrowth occur when the growth cycle is interrupted/disrupted.

2 Middle Anagen Stage

Minimizing stressors in your life can not only benefit your hair but also improve your overall health and well-being. To help manage stress and protect your hair, consider incorporating stress-reduction techniques such as yoga, meditation, deep-breathing exercises, or counselling into your daily routine. The content within this article and XYON’s Knowledge Library is intended to be used for educational purposes only. You should always con­sult with a licensed healthcare provider for all mat­ters relat­ing to your health.

It’s during this phase we are more likely to notice hair shedding while brushing or washing our hair. Don’t panic – while old hairs fall away, new hairs are growing in their place. The catagen phase, marking the transition between active growth and the resting period, begins when the anagen phase ends and typically lasts about 10 days. During periods of stress, more hair enters the telogen phase and begins to fall out.

Hair shedding may start as soon as two weeks after the first dose of radiation and will continue for a couple of weeks. Hair follicles typically enter the telogen phase, and regrowth should commence 2.5 to 3 months after the hair begins to shed. Anything that disrupts the hair growth cycle can cause more hairs to enter the telogen phase. When more hair is in the telogen phase, a greater amount of hair will shed when the hairs enter the exogen phase a few months later. A healthy lifestyle of low stress, proper diet, and gentle hair care should help promote healthy hair growth for a long time. The exogen phase is essentially an extension or a part of the telogen stage of hair growth.

This is the largest number of hair follicles you will ever have. During the anagen phase, your hair follicles are pushing out hairs that will continue to grow until they’re cut or until they reach the end of their lifespan and fall out. At any time, about 90 percent of the hairs on your head are in the anagen phase. It’s the longest phase, lasting about 3 to 5 years for the hairs on your head, though for some people a single hair could continue growing for 7 or more years. Different from hair fall, hair loss is a widespread condition that dermatologists frequently diagnose and treat.

The time each strand spends in the anagen phase determines the hair strand’s length (aside from getting our hair cut or trimmed of course!). Stress can increase the amount of time your hair spends in the ‘resting’ phases of the cycle where new hair isn’t growing. The more you can adopt techniques to minimise and deal with stress, the more your hair will benefit. If you style your hair with heat tools, it’s essential to use heat protectant prior to styling. Heat protectant shields your strands from heat damage that can often lead to hair breakage, split ends and dryness.

Some people are content in their baldness and will let it go naturally, even shaving the scalp to make it clean and free of fuzz, while others tend to grow what they can and hold onto the hair they have. Many, particularly women, who are societally expected to have fuller hair, cover their baldness with hats or wigs. And, of course, some people choose to combat the loss of hair through the use of hair regrowth medicines and treatments. Once your hair is done growing, it goes into a transition known as the catagen phase. And by “transition,” we mean that this is when your hair begins the process of falling out.