American Academy of Professional Coders (AAPC) Practice Exam

In which layer of the shaft are pigment cells located?

1. Medulla

2. Cortex

3. Cuticle

4. Shaft

The correct answer is: Cortex

The pigment cells are located in the cortex layer of the hair shaft. The cortex is the thicker middle layer that contains long strands of keratin and provides strength, color, and texture to the hair. It is within this layer that melanin, the pigment responsible for hair color, is found. The concentration and type of melanin pigment in the cortex determine whether hair is black, brown, blond, or red, among other colors. The medulla is the innermost layer of the hair shaft and is often absent in finer hair types. It doesn't contain pigment cells, which is why it's not the correct layer. The cuticle, the outermost layer, is made up of overlapping transparent cells that protect the hair shaft but do not contain pigment. The term "shaft" refers to the entire hair structure, which includes all three layers, but when specifically referring to pigment cells, it is the cortex that is relevant.