What kind of layer is the medulla considered in the hair shaft?

The medulla is indeed considered the inner core layer of the hair shaft. This central part of the hair can vary in presence and structure among different hair types; in some cases, it may be absent altogether. The medulla is surrounded by two other layers: the cortex, which provides strength and color, and the cuticle, which is the outer protective layer.

Understanding the role of the medulla is important, as it contributes to the overall structure of the hair but does not play a significant role in determining hair color or texture. The cortex is primarily responsible for the hair's characteristics, while the cuticle protects these inner layers from damage. Recognizing where the medulla fits within the hair structure helps in understanding hair composition and how different layers interact.