KATAGENESIS Meaning and
Definition
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Katagenesis refers to the process of regressive growth or the intermediate phase of hair growth cycle. It is the second stage in the hair follicle cycle, following the anagen (growth) phase, and preceding the telogen (resting) phase.
During katagenesis, the hair follicles undergo a transition period characterized by the shrinking and retraction of the hair bulb, where the hair is rooted. This results in the cessation of hair growth as the hair follicle detaches from the nutrient supply, blood vessels, and cellular activity that support the anagen phase.
The katagen phase typically lasts for a short duration, usually about two to three weeks. While the hair is no longer actively growing, it remains anchored in the scalp during this phase. The visible sign of katagenesis is the formation of a club-like structure at the base of the hair shaft known as a club hair. The club hair is a remnant of the anagen phase and eventually transitions into the telogen phase, where the hair follicle becomes completely inactive and the hair is shed.
The process of katagenesis is a natural and essential part of the hair growth cycle, allowing for the continuous renewal and cycling of hair. Understanding the different stages of hair development, including katagenesis, helps in comprehending the dynamics of hair growth and hair loss.
Etymology of KATAGENESIS
The word "katagenesis" is derived from the Greek roots "kata", meaning down or under, and "genesis", meaning origin or creation. Therefore, "katagenesis" can be understood as the process of a subsequent or downward development or creation.
