A hair shaft is considered part of the skin. The skin is also known as the "integument", or "integumentary system".
The shaft of a hair is the superficial portion of the hair that extends from the hair follicle through the skin and is recognizable as head or body hair when it protrudes through the skin.
The other word used to refer to a “hair” in this context is “pili”.
To view the location of hair shafts relative to other parts of the skin see the diagram of the structure of the skin. This may be of particular interest to students of courses in massage, reflexology, beauty therapies, and other health science or clinical courses.