What is the semilunar lighter region of the nail called?

The semilunar lighter region of the nail is called the lunula. This anatomical feature is located at the base of the nail plate and is typically more visible on the thumb and some other fingers. The lunula represents the area where new nail growth occurs and is a part of the nail matrix, which is the tissue that produces the cells that form the nail. The lighter color of the lunula is due to the fact that it is partially translucent and the underlying matrix is not fully covered by the nail plate itself. Understanding the structure and function of the lunula is important for recognizing nail health and growth patterns.