Illinois Nail Technician Practice Exam

The technical term for nails is "onyx." This term originates from the Greek word "onychon," which means "nail." Onyx specifically refers to the hard, protective plates that cover the distal phalanx of the fingers and toes in humans and many other animals.

Keratin, while related, is actually the protein that makes up the structure of nails, hair, and the outer layer of skin. Stratum refers to layers within the skin, particularly in contexts like the stratum corneum, which is a layer of dead skin cells. Dermis is the thick layer of living tissue below the epidermis that contains blood vessels, nerves, and connective tissue. Each of these terms describes different aspects of anatomy, but "onyx" is the precise terminology used specifically for nails.