Final answer:
The first stage of hair growth, during which new hair is produced, is called the anagen phase. This phase is characterized by rapid cell division at the root of the hair, pushing the hair shaft up and out.
Step-by-step explanation:
The first stage of hair growth, during which new hair is produced, is called the anagen phase. This phase is characterized by rapid cell division at the root of the hair, pushing the hair shaft up and out. It typically lasts from 2 to 7 years, during which new keratinocytes are produced by the basal cells of the hair bulb.
The first stage of hair growth, where new hair is produced, is called the anagen phase. This is the active growth phase during which the cells in the hair follicle are dividing rapidly. The stem cells in the follicle divide to produce keratinocytes, which will form the new hair strand. As these new cells are added at the base, they push the developing hair shaft upward. The anagen phase can last from 2 to 7 years, and the hair typically grows at a rate of 0.3 mm per day during this phase. After the anagen phase, the hair moves into the catagen phase, a transitional period, and then eventually to the telogen phase, where the hair is at rest.