Which part of the nail serves as a protective barrier against infection?

The cuticle is the part of the nail that serves as a protective barrier against infection. It is the thin layer of skin located at the base of the nail, where the nail meets the skin of the finger. Its primary function is to protect the area between the skin and the nail from bacteria and other pathogens that could enter during nail growth or any break in the skin. By sealing off the area, the cuticle helps prevent contaminants from causing infections, making it crucial for maintaining nail health.

In contrast, the nail plate is the hardened part of the nail that is visible and does not provide such protection. The nail bed is the tissue beneath the nail plate that supports it but does not act as a barrier against infection. The lunula, which is the crescent-shaped whitish area at the base of the nail, is primarily a part of the nail matrix and indicates where the nail grows from but does not provide protective functions like the cuticle does.