What are the three phases of the hair growth cycle?

The three phases of the hair growth cycle are indeed anagen, catagen, and telogen.

During the anagen phase, which is the active growth phase, hair follicles are producing new cells, leading to hair growth that can last for several years. This phase determines the length of the hair as it continues to grow.

The catagen phase follows, representing a transitional stage that lasts for a few weeks. In this phase, hair growth slows down, and the hair follicle shrinks, effectively preparing the hair for the next phase.

Finally, the telogen phase is the resting phase of the hair cycle. During this time, the hair does not grow but remains attached to the follicle. After this phase, the hair will eventually shed, and the cycle will begin again with a new anagen phase.

Other choices do not correctly represent the phases of hair growth. Keratin, melanin, and collagen refer to different aspects of hair composition rather than its growth cycle. The terms growth, resting, and shedding describe processes but do not define the recognized phases of the cycle. Additionally, cuticle, cortex, and medulla pertain to the structural layers of a hair strand, rather than the phases of growth.