Which structure is responsible for hair growth?

• A. Hair follicle
• B. Sebaceous gland
• C. Epidermis
• D. Dermis

Answer: (A)

The hair follicle is the primary structure responsible for hair growth. Located within the dermis, the hair follicle is a tubular structure that encases the hair root and is where the hair itself develops. The process of hair growth begins in the hair bulb, which is found at the base of the follicle, where cells multiply and keratinize to form the hair shaft. Additionally, the follicle contains specialized cells known as dermal papillae, which supply nutrients and signals necessary for hair growth and cycling.

The sebaceous gland, while associated with hair follicles and responsible for producing sebum to lubricate the hair and skin, does not play a direct role in hair growth itself. The epidermis is the outer layer of skin and primarily functions as a protective barrier, while the dermis supports the hair follicles and contains the necessary blood vessels and connective tissues. However, it is specifically the hair follicle in coordination with the dermis that is integral to the hair growth process.