Cosmetology · Hair and Scalp Science

The three main layers of the hair shaft are the cuticle, cortex, and:

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Correct answer

Medulla

A Bulb
B Papilla
C Follicle
D Medulla

Why this is the answer

The three main layers of the hair shaft are the cuticle (the tough, outermost protective layer of overlapping scales), the cortex (the middle layer that gives hair its strength, elasticity, and natural color through melanin), and the medulla (the innermost core, which may be absent in fine or very light hair). Most chemical services act on the cuticle and cortex. Knowing these three layers and their roles — especially that the cortex is where color and most chemical changes occur — is essential hair science.

Source: Scientific Concepts — Hair Shaft Layers

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About this topic: Hair and Scalp Science

Hair and scalp science covers the structure of the hair (cuticle, cortex, medulla), the follicle and growth cycle, hair types and the common scalp and hair disorders — which can be treated in the salon and which must be referred. This is one of 9 Scientific Concepts questions on hair and scalp science, each with a full explanation on a single study page.

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The three main layers of the hair shaft are the cuticle, cortex, and:

Why this is the answer

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About this topic: Hair and Scalp Science

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