Hair growth cycle

•In the lower hair bulb the matrix cells are activated; and cells grow and move up to the upper bulb where they begin to differentiate; some cells grow at a faster rate than others and form the inner root sheath

11% of hair growth in this stage on average

Hair moves up and is shed

•Once the hair emerges through the skin it is called the hair shaft

•The follicle continues to extend down into the dermis until the hair on the skin surface has reached its ultimate length