Which term describes the keratin-based plate that is the main visible portion of the nail unit?

• A. Nail Plate
• B. Free Edge
• C. Matrix
• D. Lunula

Answer: (A)

The main visible, keratin-based plate of the nail unit is the nail plate. It forms the hard, protective surface you see and sits on the nail bed. The plate is made of dead, densely packed keratinized cells that have hardened as they moved outward from the growth region underneath. Growth originates in the matrix, a tissue under the proximal nail fold; new cells are produced there and become the nail plate as they reach the tip. The pale crescent at the base is the lunula, which indicates the visible part of the matrix but is not the plate itself. The free edge is simply the portion that extends past the fingertip and can be trimmed or filed.