What is the small, cone-shaped elevation at the base of the hair follicle that fits into the hair bulb called?

The small, cone-shaped elevation at the base of the hair follicle that fits into the hair bulb is known as the dermal papilla. This structure is crucial for hair growth because it contains specialized cells and blood vessels, which provide the necessary nutrients and signals to the hair follicle. The dermal papilla plays a significant role in the hair growth cycle by influencing the formation and regeneration of hair.

The hair bulb is the rounded club-like structure at the end of the hair follicle where hair growth occurs but does not specifically refer to the elevation fitting into it. The follicular unit encompasses the hair follicle and associated structures but does not denote the specific elevation. The cuticle refers to the outer layer of the hair shaft itself, which does not pertain to the base of the hair follicle. Understanding these definitions highlights why the dermal papilla is the correct answer.