What is the primary material that makes up the nail plate?

The nail plate is primarily made up of keratin, a fibrous protein that forms the structural foundation of the nails. Keratin is essential for the durability and strength of the nail, providing the rigidity necessary to protect the underlying tissues of the fingers and toes. This protein is not only found in nails, but also in hair and the outer layer of skin, contributing to their protective and structural properties.

Collagen, while important for skin and connective tissues, is not the main component of the nail plate. Elastin provides elasticity to tissues but is not present in nails. Hyaluronic acid is involved in hydration and lubrication in various tissues, but it does not play a structural role in the composition of the nail plate. Thus, keratin being the correct answer highlights its importance as the key structural material that defines the characteristics of nails.