Structure of the hair follicle and the epidermis. The schematic shows hair follicle structures including the infundibulum, junctional zone, isthmus, sebaceous gland, bulge, bulb and hair shaft. The epidermal layers (basal, spinous, granulate and cornified) are also shown. The interfollicular epidermis is the stratified epidermis located between the hair follicles. The text describes various regions of these structures where specific stem cell populations, identified by specific markers, are located.