What is the innermost part of the hair shaft called?

The innermost part of the hair shaft is known as the medulla. This central core is often made up of loosely packed cells and air spaces, which can impact the overall structure and texture of individual hair strands. The presence or absence of the medulla can vary among different hair types and species, and it may not be present in all hair strands.

Understanding the structure of hair is essential for electrologists, as it relates to how hair grows and how it can be treated during hair removal processes. The medulla is surrounded by the cortex, which provides strength and color to the hair, while the cuticle serves as the outer protective layer. The follicle, although crucial for hair growth, is not part of the hair shaft itself but rather the structure from which the hair grows.