Hair follicle definition, the part of the skin that produces hair. Each hair follicle is made up of a group of cells that form the hair shaft, the root sheath, and the sebaceous gland. The hair shaft is the visible part of the hair, while the root sheath is the part that anchors the hair in the skin.
Hair follicles are important for maintaining the health of the skin and hair. They produce sebum, which helps to keep the skin and hair moisturized. Hair follicles also play a role in thermoregulation, helping to keep the body warm in cold weather. Hair follicles are a complex and fascinating part of the human body, and they continue to be a subject of scientific research.