During which phase does hair detach from the papilla?

The correct answer is Catagen. This phase is characterized by the transition of hair from its active growth stage into a resting state. During catagen, the hair follicle undergoes a process of shrinkage, and the hair shaft detaches from the papilla, which is the structure that provides nutrients and signals for hair growth. As a result, the hair strand is no longer receiving the nutrients necessary to sustain its growth, leading to the eventual shedding of the hair in the subsequent telogen phase. This process is crucial for maintaining healthy hair growth cycles, allowing new hair to emerge as older hair falls out.

In contrast, during the anagen phase, hair is actively growing and firmly anchored in the papilla, while the telogen phase represents a resting period where the hair is fully detached but not yet shed. Interphase refers to the stage of cell division but does not specifically apply to hair growth cycles. Therefore, catagen is the specific phase where the detachment from the papilla occurs, signifying an important transition in the hair lifecycle.