Which three parts compose the hair strand?

The hair strand is composed of three key layers: the medulla, cortex, and cuticle. The medulla is the innermost layer, which may be absent in some types of hair but can contain air spaces and soft keratin. The cortex is the middle layer, providing strength, elasticity, and color to the hair, as it contains the majority of the hair's pigment and is crucial for its overall structure. The cuticle, the outermost layer, consists of overlapping, scale-like cells that protect the inner layers and help to maintain moisture and shine.

This structure is significant because each layer plays an essential role in the overall health and appearance of the hair. Understanding these components is vital for estheticians, as treatments and products can be tailored to target specific layers, enhancing the hair's condition and aesthetic appeal.