Final answer:
The hair papilla is a mass of connective tissue, blood capillaries, and nerve endings at the base of the hair follicle. The hair root is the part of the hair that is anchored in the hair follicle and lies below the surface of the skin. The hair shaft is the part of the hair that is not anchored to the hair follicle and is visible above the skin's surface.
Step-by-step explanation:
The hair papilla is a mass of connective tissue, blood capillaries, and nerve endings at the base of the hair follicle. It provides the hair follicle with nutrients and signals for hair growth.
The hair root is the part of the hair that is anchored in the hair follicle and lies below the surface of the skin. It ends deep in the dermis at the hair bulb and includes a layer of mitotically active basal cells called the hair matrix.
The hair shaft is the part of the hair that is not anchored to the hair follicle and is visible above the skin's surface. It consists of dead cells and is primarily made of keratin, a protein that gives hair its strength and structure.