Which part of the hair is considered the root?

The root of the hair is indeed the part that resides below the surface of the epidermis. This area is crucial for hair growth and development, as it is where the hair follicle is located. The hair roots are embedded in the skin and receive essential nutrients and blood supply from nearby blood vessels, allowing hair to grow and be nourished.

The visible part of the hair, which is above the skin, is referred to as the hair shaft. It does not play a role in the growth or nourishment of the hair. The outermost layer of the hair, known as the cuticle, provides protection but is not the root itself. Additionally, while the process of hair formation involves growth, the definition of the root specifically pertains to its location below the skin surface rather than a stage in the hair's development. Understanding these distinctions is key to grasping the anatomy of hair and its growth cycle.