History and Physical (H&P) Exam 1 Practice 2026 - Free Practice Questions and Study Guide

The protective seal at the base of the nail is the cuticle. The cuticle, or eponychium, is a band of skin that overlaps the nail plate and adheres to the proximal nail fold, creating a tight barrier that prevents moisture and microbes from getting under the skin around the nail. The visible crescent area (lunula) is simply part of the nail bed and doesn’t serve this barrier function. The proximal and lateral nail folds provide surrounding skin protection, but the cuticle’s sealing action is what most directly stops seepage of moisture and infection at the nail border.