What structure does a hair fibre have?

The hair fibre consists of three concentric layers. The medulla is surrounded by the cortex which in turn is covered by the cuticle, the outer hair layer. The cuticle consists of small overlapping scales which run along from hair roots to hair ends. Cosmetic hair care products can hardly reach the hair medulla. The hair cortex, which contains the natural pigment, is often compromised by dyeing, bleaching, perms and hair straightening. The cuticle is a hair structure segment which is most vulnerable to mechanical damage.

Structure of hair fibr
Structure of hair fibre

Source: www.excellence.qia.org.uk