The matrix, sometimes called[2] the matrix unguis, keratogenous membrane, nail matrix, or onychostroma, is the tissue (or germinal matrix) which the nail protects.[3] It is the part of the nail bed that is beneath the nail and contains nerves, lymph and blood vessels.[4] The matrix is responsible for producing cells that become the nail plate. The width and thickness of the nail plate is determined by the size, length, and thickness of the matrix, while the shape of the fingertip itself shows if the nail plate is flat, arched or hooked.[5] The matrix will continue to grow as long as it receives nutrition and remains in a healthy condition.[4] As new nail plate cells are made, they push older nail plate cells forward; and in this way older cells become compressed, flat, and translucent. This makes the capillaries in the nail bed below visible, resulting in a pink color.[6]