hair follicle

A tube-like invagination of the epidermis from which the hair shaft develops and into which sebaceous glands open. The hair follicle is lined by a cellular inner and outer root sheath of epidermal origin and is invested with a fibrous sheath derived from the dermis. (Stedman, 26th ed) Follicles of very long hairs extend into the subcutaneous layer of tissue under the skin.

Definition from MeSH (D018859), National Library of Medicine, read 2026-09-23. NLM revises MeSH; this copy may not reflect its current record.