What are the slits or furrows on the sidewall of the nail called?

The slits or furrows located on the sidewall of the nail are referred to as nail grooves. These grooves are important anatomical features that help to define the shape of the nail and provide structure to the surrounding skin. Nail grooves play a role in guiding the nail growth and ensuring that the nail is properly positioned as it emerges from the nail matrix.

Understanding this term is essential for anyone studying nail structure, as it highlights the interaction between the nail and the surrounding tissue. While terms like lunula, nail plate, or natural nail refer to different aspects of the nail anatomy, they do not describe the sidewall features specifically. The lunula pertains to the visible part of the nail matrix at the base of the nail, the nail plate is the hard keratinous portion of the nail that we typically see, and the natural nail describes the entire nail in its unaltered state. Thus, identifying nail grooves is critical for comprehending the full anatomy and potential disorders related to the nail.