Hair Shaft Structure Explained Simply
The visible part of hair — the shaft — has a layered design. The outer cuticle acts as a protective shield, controlling shine and moisture retention. Beneath it lies the cortex, which gives hair strength, elasticity, and color through pigment cells. Some hair types also contain a medulla at the center, though it is not always present. Damage to the cuticle exposes the cortex, making hair prone to breakage and dryness. While treatments can improve appearance, true hair strength depends on how well the shaft was formed inside the follicle.