Hair Loss: Androgenic Alopecia

SurgMedia

10 Jul 202102:51

Summary

TLDRThe video script explains the three-phase hair growth cycle: anagen, catagen, and telogen. Hair growth occurs in the anagen phase, with nutrients supplied by the dermal papilla. The catagen phase sees halted growth, and telogen is when the old hair is shed. Androgenetic alopecia shortens the anagen phase, leading to hair loss. Minoxidil, a treatment, may stimulate hair growth by increasing blood supply and follicle activity, potentially reversing hair loss. Visible results are expected after 2-4 months of treatment.

Takeaways

🌀 The hair growth cycle is a three-phase process occurring at the hair follicles.
🌱 During the anagen phase, hair matrix cells actively proliferate, producing new cells that form the hair shaft.
🔄 The catagen phase is a transitional stage where hair growth stops and the hair shaft keratinizes.
🍂 In the telogen phase, hair is shed as the follicle prepares for a new growth cycle.
🚿 Androgenetic alopecia is linked to higher levels of certain androgens, leading to shorter anagen and longer telogen phases.
📉 These hormonal changes result in progressively thinner and shallower hair follicles over time.
🌟 The typical pattern of hair loss due to androgenetic alopecia is observed at the vertex and frontotemporal regions.
💊 Minoxidil, a treatment for hair loss, may work by opening ATP-sensitive potassium channels and promoting hair growth.
🌡️ It might also increase vascular endothelial growth factor expression and enhance follicle vascularization.
🔁 The use of minoxidil can stimulate longer anagen phases, shorten telogen phases, and reactivate dormant follicles.
⏱️ It typically takes 2 to 4 months of minoxidil treatment to see noticeable improvements in hair growth.

Q & A

What is the three-phase cycle of hair growth?
-The three-phase cycle of hair growth includes the anagen, catagen, and telogen phases. It takes place at the hair follicles where cells in the hair matrix are responsible for hair growth.
How do cells in the hair matrix receive nutrients during the anagen phase?
-During the anagen phase, cells in the hair matrix receive nutrients from a capillary loop at the dermal papilla.
What happens during the anagen phase of hair growth?
-During the anagen phase, the hair matrix actively proliferates, new cells are continually produced, and pushed upward to differentiate and form the hair shaft.
How long does the anagen phase typically last?
-The anagen phase typically lasts for two to six years.
What occurs during the catagen phase of the hair growth cycle?
-In the catagen phase, matrix cells cease activity, hair growth stops, and the base of the hair shaft keratinizes and migrates upward away from the papillary blood supply.
What is the telogen phase and what happens during this phase?
-The telogen phase is the final stage of the hair growth cycle where hair transforms into club hairs, which then move up the hair sheath. At the start of a new anagen phase, the follicle re-grasps the papilla and a new hair grows.
How does androgenetic alopecia affect the hair growth cycle?
-Androgenetic alopecia is associated with increased levels of certain androgens that lead to shorter anagen phases and longer telogen phases, resulting in progressively shallower follicles and thinner hair fibers.
What is the typical hair loss pattern seen in androgenetic alopecia?
-The typical hair loss pattern in androgenetic alopecia is seen at the vertex and frontotemporal regions of the head.
How does minoxidil contribute to hair regrowth?
-Minoxidil may act as an ATP-sensitive potassium channel opener and may elevate the expression of vascular endothelial growth factor, supporting follicle vascularization and potentially stimulating longer anagen phases and shortening telogen phases.
What is the initial response some patients may notice when using minoxidil?
-Some patients may notice an initial increase in hair shedding due to an abbreviated telogen phase when they first start using minoxidil, which is temporary and indicative of a response to the treatment.
How long does it typically take to see visual improvement in hair growth with minoxidil?
-It typically takes two to four months of treatment with minoxidil to reverse the process of androgenetic alopecia enough for patients to see visual improvement in their hair.

Outlines

00:00

💇‍♂️ Hair Growth Cycle and Androgenetic Alopecia

The paragraph explains the hair growth cycle, which occurs in three phases: anagen, catagen, and telogen. During the anagen phase, hair cells actively divide and push upward to form the hair shaft. This phase lasts for two to six years. Following this, the catagen phase ensues, where hair growth halts, and the hair shaft keratinizes, moving away from the blood supply. The telogen phase is the final stage where the hair becomes a club hair and is shed as a new hair begins to grow. Androgenetic alopecia is linked to hormonal changes that shorten the anagen phase and prolong the telogen phase, resulting in thinner and shallower hair follicles over time. This condition typically manifests as hair loss at the vertex and frontotemporal regions.

Mindmap

Keywords

💡Follicles

Follicles are the tiny sacs in the skin from which hair grows. In the context of the video, follicles are the site of the three-phase hair growth cycle, playing a crucial role in the production and maintenance of hair. The video discusses how the hair matrix within the follicles is responsible for hair growth, receiving nutrients from the dermal papilla.

💡Hair Matrix

The hair matrix is a group of cells located at the base of the hair follicle that is responsible for the production of new hair cells. The video explains that during the anagen phase, the hair matrix actively proliferates, producing new cells that form the hair shaft. This concept is central to understanding the hair growth process.

💡Anagen Phase

The anagen phase is the growth phase of the hair cycle, lasting between two to six years. The video describes how, during this phase, the hair matrix actively produces new cells that are pushed upward to form the hair shaft. This phase is a key part of the hair growth cycle and is directly related to the length and health of hair.

💡Catagen Phase

The catagen phase is a transitional phase in the hair growth cycle where the matrix cells cease activity and hair growth stops. The video mentions that during this phase, the base of the hair shaft keratinizes and moves upward, away from the blood supply, indicating the end of the growth phase and the beginning of the resting phase.

💡Telogen Phase

The telogen phase is the resting phase of the hair growth cycle, where the hair is shed and replaced by new growth. The video explains that during this phase, the hair transforms into club hairs and migrates up the hair sheath, eventually being shed as a new hair begins to grow from the follicle.

💡Androgenetic Alopecia

Androgenetic alopecia, also known as male or female pattern baldness, is a common type of hair loss. The video associates this condition with increased levels of certain androgens that lead to shorter anagen phases and longer telogen phases, resulting in progressively shallower follicles and thinner hair fibers.

💡Minoxidil

Minoxidil is a medication used to treat hair loss, particularly androgenetic alopecia. The video suggests that minoxidil may act as an ATP-sensitive potassium channel opener and may increase the expression of vascular endothelial growth factor, supporting follicle vascularization and potentially leading to longer anagen phases and shorter telogen phases.

💡Vascular Endothelial Growth Factor (VEGF)

VEGF is a protein that stimulates the formation of new blood vessels. In the context of the video, minoxidil may elevate the expression of VEGF, which could enhance follicle vascularization and contribute to hair regrowth by improving the blood supply to the hair follicles.

💡Fenestrations

Fenestrations refer to the small openings in the walls of certain blood vessels, particularly capillaries. The video mentions that minoxidil may increase fenestrations in the parafollicular capillary network, which could support the delivery of nutrients to the hair follicles and promote hair growth.

💡Rogaine

Rogaine is a brand name for minoxidil and is commonly used to treat hair loss. The video discusses how Rogaine products can reverse the process of androgenetic alopecia by stimulating hair regrowth, with patients typically noticing visual improvement after two to four months of treatment.

💡Hair Shedding

Hair shedding is the natural process of hair loss as part of the hair growth cycle. The video notes that some patients may initially experience increased hair shedding due to an abbreviated telogen phase, which is a temporary response to Rogaine product use and indicative of the product's effectiveness.

Highlights

The hair growth cycle is a three-phase process occurring at the follicles.

Hair matrix cells are responsible for growth and receive nutrients from the dermal papilla.

During the anagen phase, the hair matrix actively proliferates, producing new cells.

The anagen phase lasts for two to six years, during which hair actively grows.

The catagen phase is a transition phase where hair growth stops and cells cease activity.

In the telogen phase, hair transforms into club hairs and moves up the hair sheath.

The follicle re-grasps the papilla at the start of a new anagen phase.

Androgenetic alopecia is linked to increased levels of certain androgens.

Androgenetic alopecia leads to shorter anagen phases and longer telogen phases.

The result of these changes is hair loss in the vertex and frontotemporal regions.

Minoxidil diffuses to the hair follicle and may act as an ATP-sensitive potassium channel opener.

Minoxidil may elevate the expression of vascular endothelial growth factor.

Minoxidil increases fenestrations in the parafollicular capillary network.

These mechanisms may stimulate longer anagen phases and shorten telogen phases.

Minoxidil can trigger dormant follicles into a new growth cycle.

An initial increase in hair shedding may occur due to an abbreviated telogen phase.

This initial shedding is temporary and indicative of a response to minoxidil treatment.

Treatment with minoxidil products typically takes two to four months to show visual improvement.