From what part of the body do hairs develop?

Hairs develop from the epidermis, specifically from the hair follicles which are structures located in the deeper part of the epidermis. The hair follicle is an invagination of the epidermis that extends into the dermis, but it originates from epidermal cells. During the process of hair formation, these cells multiply and differentiate, producing hair shafts that grow outward from the skin surface.

Understanding that the epidermis is the outermost layer of skin is crucial, as it is primarily responsible for generating new hair cells. The other layers of skin—such as the dermis and hypodermis—do play supportive roles, providing nourishment and insulation, but they do not directly give rise to hair itself. The follicular layer refers to parts associated with hair follicles, but when considering the origin of hair, it is the epidermis that is the critical layer where hair development begins.