Which structure at the base of the hair follicle is primarily responsible for nourishing the hair and enabling growth?

• A. Hair root
• B. Cortex
• C. Cuticle
• D. Dermal papilla

Answer: (D)

The structure at the base of the hair follicle that nourishes the hair and enables growth is the dermal papilla. It sits right under the hair matrix and is fed by a rich supply of tiny blood vessels. Those vessels deliver oxygen and nutrients directly to the rapidly dividing matrix cells, which produce the hair shaft. The dermal papilla also sends signaling cues that regulate the follicle’s growth cycle, helping the hair to grow during the anagen phase and transition through other phases as needed.

The other parts you see—the hair root, cortex, and cuticle—play different roles. The cortex and cuticle are layers of the hair shaft itself, providing strength and protection, not delivering nutrients. The hair root is the portion of the hair that lies within the follicle, including the growing region, but the actual nourishment comes from the blood vessels in the dermal papilla feeding the matrix above it.