A longitudinal section of a hair (*), stained yellow, is present in the lumen of the follicle.

This follicle is lined by the outer root sheath (arrows).

A sebaceous gland (+) opens into the lumen of the follicle (arrowhead). In the sebaceous gland a layer of basal cells proliferate and give rise to large pale cells containing lipid droplets. As these cells migrate toward the mouth of the gland the nuclei of the cells dissolve and the degenerating cells and their lipid content are expulsed into the space surrounding the hair. Sebaceous glands are said to be holocrine since the cellular residues are wholly excreted.

The following elements associated with the hair follicle are labelled:

• Connective tissue sheath of the hair follicle (A)
• Arrector pili smooth muscle (B), which is inserted in the sheath of the hair
• Sections of a vessel (V) and a nerve (N)

Stain: H–­­E
Magnification: ×450