Hair is a primary characteristic among mammals and plays a wide range of functions, including thermoregulation, physical protection, sensory activity and is also used in social interaction. The hair shaft consists of terminally differentiated keratinocytes that are produced by the hair follicle. Hair follicles are created during fetal skin development and rely on tightly regulated ectodermal-mesodermal interactions. After birth, mature and actively growing hair follicles eventually become anchored in the subcutis and periodically regenerate by spontaneously undergoing repetitive cycles of growth (anagen), apoptosis-driven regression (catagen) and relative quiescence (telogen)*.
Each individual has between 100,000 and 150,000 hairs on their scalp. Now, let's discover how hair intrinsically ages, what impact hair color has, the difference between curly and straight hair and much more...