Final answer:
The condition where the cuticle covers most of the nail plate is called pterygium. It involves the forward growth of the eponychium over the nail body, which can lead to potential complications. The nail body is a keratinous structure growing from the nail root and is anchored in place by the lateral nail fold.
Step-by-step explanation:
The condition where the cuticle grows forward and covers most of the nail plate, also known as the nail body, is typically referred to as pterygium. This is an abnormal condition that can occur due to various factors, including trauma, skin diseases, or nail disorders. The cuticle, or eponychium, is a fold of epithelium that normally extends over the nail bed at the proximal end of the nail body. Its primary function is to protect the nail matrix from infections.
The nail body itself is the main keratinous plate that forms the visible part of the nail, primarily composed of densely packed dead keratinocytes. It grows continuously from the nail root, which contains a matrix of proliferating cells from the stratum basale of the epidermis. The lateral nail fold helps to anchor the nail body in place, and the nail bed beneath it is rich in blood vessels, contributing to the pink appearance of the nails, except for the whitish lunula.
If the cuticle grows over the nail plate, it may compromise the normal protective function of the nails and lead to other complications such as infections or impaired nail growth. Treatment for this condition can vary depending on its severity and the underlying cause.