What Is a Hair Follicle?

The hair follicle is a bag-like epithelium formed continuously by epidermal cells. Its base is a dermal papilla with a recessed dermis and a hair in the center. One side of the standing hair muscle is obliquely attached to the wall of the hair follicle. Above the attachment point is the short neck of the sebaceous gland that leads into the hair follicle. hole. The hair follicle is located in the dermis and subcutaneous tissue and can be divided into three parts: the funnel part of the hair follicle, the isthmus part of the hair follicle, and the lower part of the hair follicle.

Basic Information

Chinese name

Hair follicle

Constitute

Inner hair root sheath, outer hair root sheath and fiber sheath

Features

Hair absorbs nutrients from the body through the hair follicle

Hair follicle composition

The hair follicle is a sheath-like structure surrounding the hair root, and is divided into an inner hair root sheath, an outer hair root sheath, and a fiber sheath from the inside to the outside.
1. Inner hair root sheath The inner hair root sheath originates from the epidermis and is divided into three layers from the inside to the outside, namely the sheath sheath, Huxley layer, and Henler layer. Sheath cortex, also called sheath keratin, is a layer of overlapping cells; the Huxley layer is composed of 1 to 3 cells; the Henler layer is composed of a single row of flatter cells.
2. Outer hair root sheath Outer hair root sheath originates from the epidermis and consists of one to several layers of cells. The outermost layer is a rectangular columnar epithelial cell.
3. Fibre sheath Fibre sheath originates from the dermis and can be divided into 3 layers. The inner layer is a transparent glass-like film. The middle layer is composed of dense, wavy fibrous tissue. The outer layer is composed of collagen fibers and elastic fibers. Connective tissue has no clear boundaries.

Hair follicle function

Hair grows from the hair follicles, and the hair absorbs nutrients from the body through the hair follicles to support hair growth. The epithelial cells of the hair follicle tissue can divide and multiply, making the hair constantly change and grow, but as the age increases, the role of the hair follicle gradually weakens, and the phenomenon of hair loss occurs.