Hyponychium refers to which part of the nail?

The hyponychium is the part of the nail that refers specifically to the skin located underneath the free edge of the nail. It serves as a protective barrier between the nail plate and the surrounding skin, helping to prevent the entry of pathogens and debris into the nail bed. This area is important for nail health because it plays a role in anchoring the free edge of the nail and protecting the sensitive skin underneath.

The other options describe different parts of the nail structure but do not accurately define the hyponychium. For instance, the skin on top of the nail pertains to the nail plate and the surrounding epidermis, while the cuticle relates to the skin that overlaps the base of the nail plate. The outer edge of the nail plate itself is simply the extremity of the keratinized nail structure and does not refer to a specific area of skin like the hyponychium does. Understanding these distinctions is essential for proper nail care and anatomy.