Final answer:
The nail matrix, at the proximal end of the nail, is responsible for nail growth. It is a portion of the epidermal tissue that includes stem cells which divide to allow the nail to grow continuously. The matrix produces the nail root, which creates the nail plate as it grows longer.
Step-by-step explanation:
The nail matrix is responsible for nail growth. It is a thickened proximal portion of the nail bed where the nail originates. The matrix is a deep layer of epidermal tissue located at the proximal end of a nail. It contains a matrix of proliferating cells from the stratum basale that causes the nail to grow. The cells in the nail matrix keep dividing, producing the nail root which then forms the nail plate as the nail grows out from the skin.
The nail bed is the area of skin lying beneath the nail plate, appearing pink due to blood vessels in the dermis, but at the base of the nail, you'll notice the lunula, a crescent-shaped whitish area, which is a visible portion of the nail matrix. Surrounding the nail matrix and plate are several structures including the nail folds, which help anchor the nail body, and the eponychium or nail cuticle that seals the space between the nail and the skin, protecting against infection.