What is divided into three parts: the cuticle, the cortex and the medulla?

• A. Hair shaft
• B. Hair root
• C. Hair follicle
• D. Hair strand

Answer: (A)

The three parts—cuticle, cortex, and medulla—make up the hair shaft, the portion of hair that extends above the surface of the skin. The cuticle is the thin, outer protective layer of overlapped cells, the cortex is the thick middle layer that contains keratin and pigment, and the medulla is the inner core that may be present or absent in finer hair. The root sits below the skin in the follicle, where growth occurs, and a hair strand generally refers to the hair itself but the specific layered structure described here is the shaft.