Hair is primarily made up of what type of cells?

Hair is primarily made up of matrix cells, which are responsible for the production of hair strands. The hair follicle contains a region called the hair bulb, where these matrix cells rapidly divide and differentiate. As they move upward through the hair follicle, they keratinize and form the hair shaft. This process contributes to the overall structure of the hair, which is primarily composed of keratin, a protein.

Furthermore, while keratinocytes are indeed involved in the formation of hair due to their role in producing keratin, they do not specifically refer to the cells located in the hair matrix essential for hair growth. Fibroblasts are more associated with connective tissue and play a role in wound healing and collagen production. Melanocytes, on the other hand, are responsible for pigment production in the hair but do not form the hair structure itself. Therefore, matrix cells are rightly identified as the primary cells involved in hair formation and growth.