PSI Barbering Practice Exam

Which structure contains the blood and nerve supply that provides the nutrients needed for hair growth?

1. Hair shaft

2. Hair bulb

3. Dermal papilla

4. Hair follicle

The correct answer is: Dermal papilla

The dermal papilla is the structure that contains the blood and nerve supply necessary for hair growth. It is located at the base of the hair follicle and sits within the hair bulb. The dermal papilla is essential because it provides the essential nutrients and oxygen required for the cells in the hair bulb to proliferate and produce new hair. The blood vessels within the dermal papilla deliver vital nutrients to the hair matrix, where hair cells divide and grow. Additionally, nerve endings in the dermal papilla play a role in sensation, allowing the body to perceive touch and pressure on the hair. This relationship is crucial, as a robust blood supply can enhance hair growth by ensuring the hair follicle receives everything it needs to produce healthy hair strands. The other mentioned structures do play significant roles in hair growth and overall hair health, but they do not house the blood and nerve supply directly. The hair shaft is the visible part of the hair that has no biological function pertaining to growth, the hair bulb contains actively dividing cells but relies on the dermal papilla for nutrient supply, and the hair follicle is the overall structure that surrounds the hair but does not itself provide the direct blood and nerve supply that the dermal papilla does.