Final answer:
The shortest phase of the hair growth cycle is known as the catagen phase, lasting 2 to 3 weeks. It marks the transition between the active growth anagen phase and the resting telogen phase.
Step-by-step explanation:
The shortest part of the hair growth cycle is known as the catagen phase. This phase acts as a transitional stage where the hair stops growing, detaches itself from the dermal papilla, and prepares to enter the resting phase. The catagen phase lasts for about 2 to 3 weeks, making it the shortest of the three phases.
Detailed explanation of the hair growth cycle reveals that it consists of three distinct phases: anagen, catagen, and telogen. Each phase plays a crucial role in the regeneration and maintenance of hair. The anagen phase is the growth period lasting several years, while the telogen phase is the resting period that leads up to hair shedding.