The skin is the largest organ in the human body. It is comprised of multiple layers of tissue and guards the underlying muscles, bones, ligaments and internal organs.
Hair is most often treated as an accessory, but it is meant to protect us by providing some insulation and keeping out harmful debris.
Nails are made of keratin, a hardened protein that is also in hair and skin. Their role is to protect the delicate tissues at the ends of fingers and toes.