Which layer of the hair contains most of the pigment and elasticity?

• A. Medulla
• B. Cortex
• C. Cuticle
• D. Dermis

Answer: (B)

Pigment and elasticity are primarily determined by the cortex, the middle layer of the hair shaft. The cortex contains most of the melanin pigment that gives hair its color, and it also houses the keratin-filled cortical cells that give hair its strength and ability to stretch without breaking. The outer cuticle is a protective layer of scale-like cells that contributes to shine and smoothness but holds little pigment and provides less elasticity. The medulla, when present, is the inner core and often contains little pigment and varying structure, so it doesn’t define color or elasticity as much. The dermis is skin tissue, not part of the hair shaft, so it isn’t involved in hair pigment or elasticity.