What is a hair folicle?

A hair follicle is a tiny, tube-shaped organ in the skin that produces hair. Each follicle contains a hair shaft, which is the visible part of the hair, and a hair root, which is embedded in the skin. The hair root is surrounded by a group of cells called the hair matrix, which is responsible for producing new hair cells.

The hair follicle also contains a sebaceous gland, which produces an oily substance called sebum. Sebum helps to keep the hair and skin moisturized.

Hair follicles are found all over the body, but they are most concentrated on the scalp, eyebrows, eyelashes, and underarms. The number of hair follicles on a person's body is determined by genetics.

The hair growth cycle is the process by which hair follicles produce new hair cells. The hair growth cycle consists of three phases:

* Anagen phase: This is the active phase of hair growth, during which the hair follicle produces a new hair shaft.

* Catagen phase: This is a transitional phase during which the hair follicle shrinks and the hair shaft is released from the skin.

* Telogen phase: This is the resting phase of hair growth, during which the hair follicle remains inactive.

The hair growth cycle typically lasts for about 2 to 6 years. After the telogen phase, the hair follicle enters the anagen phase again and begins to produce a new hair shaft.