Hair today and tomorrow
Though it’s sometimes too thin and sparse to be easily visible, hair covers the entire human body with a few obvious exceptions: our lips, palm of our hands and bottoms of our feet. Hair sprouts from skin organs called follicles, which contain a group of epithelial cells and melanocytes that rapidly divide to produce the hair fiber. The hair follicle is connected to the epidermis by a set of muscles called arrector pili, which push the hair up and create “goosebumps.” Near these muscles are groups of stem cells residing in a structure called “the bulge,” colored blue in this confocal microscopy image of mouse epidermis by Ian Smyth of Monash University in Australia. These stem cells continually supply the follicle with hair-producing cells.