The term used to describe the inner structure of hair, also called the core, is

• A. Core
• B. Cortex
• C. Medulla
• D. Root

Answer: (A)

Medulla is the term for the innermost layer of the hair shaft, the central core. It sits at the very center and is made of loosely packed cells with sometimes air spaces; in some hair types it may be absent. Surrounding it is the cortex, the thicker layer that provides most of the hair’s strength and color, while the root is the portion anchored in the follicle and not part of the shaft’s internal structure. Because the inner core of hair is specifically called the medulla, that is the correct term for the inner structure described as the core.