Texas Class A Barber Written ExamAnatomy and PhysiologyMedium
A barber is preparing to perform a chemical service that requires careful consideration of the client's hair porosity. Understanding the layers of the hair strand, which layer is primarily responsible for determining the hair's ability to absorb moisture and chemicals?
- ACortex
- BCuticle
- CHair bulb
- DMedulla
Show answer & explanationAnswer & explanation
Correct answer: B. Cuticle
The cuticle is the outermost layer of the hair, composed of overlapping scales. Its condition (tightly closed or raised) directly dictates the hair's porosity, or its ability to absorb moisture and chemicals. A healthy, closed cuticle indicates low porosity, while a damaged, raised cuticle indicates high porosity.
Why the other options are wrong
- A. The cortex is the middle layer, responsible for strength and elasticity, and contains melanin, but its absorption is regulated by the cuticle.
- C. The hair bulb is located in the scalp and is part of the hair follicle, not a layer of the hair strand itself.
- D. The medulla is the innermost, sometimes absent, core of the hair and does not significantly impact porosity.
Hair Porosity & Cuticle
Hair porosity, the hair's ability to absorb moisture and chemicals, is primarily determined by the condition and arrangement of the cuticle layer.
- Cuticle: outermost protective layer, overlapping scales.
- Tightly closed cuticle = low porosity.
- Raised/damaged cuticle = high porosity.
- Important for chemical service results.
Memory trick: Cuticle's condition controls chemical's climb.