What is the innermost layer of the hair called?

The innermost layer of the hair is referred to as the medulla. This central part can be described as a soft and spongy core that may not be present in all types of hair, especially finer or thinner hair strands. The medulla is surrounded by the cortex, which provides strength and color to the hair, and outside of that is the cuticle, a protective layer. The hair follicle, while crucial for hair growth and anchoring the hair into the scalp, is not a layer of the hair strand itself but rather the structure from which the hair develops. Understanding the structure of hair is essential for barbers as it helps them in selecting appropriate techniques and products for hair care and styling.