For example, water disrupts some of these bonds. High humidity can cause the hair to manifest its natural shape. Hair Life Cycle Hair originates in a follicle, which is a cavity in the skin that holds and protects the active or living cells that become the nonliving strand of hair. Each hair follicle operates independently of the other hair follicles. Because of this, each individual hair may be in a different phase of growth.
Hair shedding usually occurs in the transition phase, but can also occur in the resting phase.
The hair root produces the cells that form the living part of the hair. This pushes the cells that already exist up and out from the follicle. As the distance from the follicle increases, the hair loses its nuclear DNA and becomes a strand of cross-linked proteins. The only living parts of hair are the cells within the hair follicle in the skin. After a definite period of growth, the hair follicle goes into a transitional phase.