NIC Barber Written (Theory) ExamScientific ConceptsHard
A barber is explaining the structure of hair to a client. The client asks which part of the hair is responsible for its elasticity and strength. The barber correctly identifies this as the middle layer of the hair shaft. What is this layer called?
- ACortex
- BFollicle
- CCuticle
- DMedulla
Show answer & explanationAnswer & explanation
Correct answer: A. Cortex
The cortex is the middle layer of the hair shaft, and it contains the melanin (pigment) and the fibrous protein structures (keratin) that provide hair with its strength, elasticity, and texture. The cuticle is the outer protective layer, and the medulla is the innermost core, not always present.
Why the other options are wrong
- B. The follicle is the structure in the skin that produces hair, not a layer of the hair shaft itself.
- C. The cuticle is the outermost protective layer, providing shine and smoothness, but not primarily elasticity and strength.
- D. The medulla is the innermost core, often absent in fine hair, and its function is not primarily related to strength or elasticity.
Hair Cortex
The thickest middle layer of the hair shaft, providing strength, elasticity, and color.
- Composed of keratin proteins and melanin.
- Determines hair's texture and elasticity.
- Where most chemical changes occur (e.g., perms, color).
- Surrounded by the cuticle, surrounds the medulla.
Memory trick: CMC: Cuticle, Cortex, Medulla - Layers from Out to In.