What are the three primary parts of a hair strand?

The three primary parts of a hair strand are the cuticle, cortex, and medulla.

The cuticle is the outermost layer, consisting of overlapping cells that protect the inner layers of the hair and help to maintain its structure and shine. It serves as a barrier against environmental damage and contributes to the overall durability of the hair strand.

The cortex is located beneath the cuticle and is the thickest layer of the hair. It contains keratin (the protein that makes up hair), and its structure influences the hair's strength, elasticity, and color. The cortex is where most of the hair's characteristics, such as texture and appearance, are determined.

The medulla, which is the innermost layer, is often absent in finer hair types but can be present in thicker hair. Its function is not well understood in terms of influencing hair properties, but it may play a role in the hair's overall structure and flexibility.

This understanding of the hair structure is fundamental in the field of cosmetology and barbering, as each part of the hair plays a significant role in hair care, styling, and chemical treatments.