The cuticle layer of hair acts to protect the cortex layer underneath
. It is the cortex layer that gives hair fibre its shape, resilience and cosmetic attributes.
A microscopic view of the cortex, lengthwise, shows that the cortex is packed together with cortical cells from root to tip. A microscopic view of the cortex in a cross-section examination is like looking at an electric cable with hundreds of wires packed closely together. The cortical cells are packed with fine macro- and micro fibrils. The way that cortical cells are packed is a major contribution to the shape of "ethnic" hair.