Chapter 9 – NAIL Structure Growth

The nail plate is primarily composed of keratin, a tough protein that also makes up hair and the outer layer of skin. Keratin provides strength and durability to the nail, allowing it to protect the fingertip. Unlike collagen and elastin, which are found in connective tissues, keratin forms a hard, protective structure. Melanin is responsible for pigment in skin but does not contribute to nail composition.

The nail matrix is the part of the nail unit responsible for producing new nail cells. As these cells grow and harden (keratinize), they form the nail plate. The matrix is located beneath the skin at the base of the nail, and its health directly affects nail growth and appearance. Damage to the matrix can result in abnormal nail growth or deformities.

The cuticle is a layer of dead tissue that seals the space between the nail plate and the surrounding skin, preventing bacteria and fungi from entering. This barrier helps protect the nail matrix and nail bed from infections. While the cuticle is important for nail health, it does not provide nutrients or directly contribute to nail growth. Proper cuticle care maintains overall nail health and prevents damage.

The eponychium is the living tissue at the base of the nail plate that covers the matrix and the lunula. Unlike the cuticle (which is dead tissue), the eponychium acts as a protective seal against infections. It is often mistakenly pushed back too aggressively in manicures, which can lead to infections and nail damage. Proper eponychium care supports healthy nail growth and protection.

The hyponychium is a thickened layer of skin beneath the free edge of the nail that acts as a protective barrier. Its main function is to prevent bacteria, fungi, and other microorganisms from entering the nail bed, reducing the risk of infection. Unlike the matrix, the hyponychium does not produce nail cells, but it plays a key role in maintaining nail health. Keeping the hyponychium intact is essential for preventing nail infections.

Specialized ligaments connect the nail bed and matrix bed to the underlying bone, providing stability and support to the nail unit. These ligaments ensure that the nail remains properly anchored and aligned during growth. Unlike the matrix, they do not produce new nail cells, but they help maintain the structural integrity of the nail unit. Healthy ligaments contribute to strong and well-formed nails.