Final answer:
The hair bulb is the structure at the base of the hair root, the hair papilla is a mass of connective tissue at the base of the hair follicle, the hair root is the part of the hair anchored in the follicle, and the hair shaft is the exposed part of the hair.
Step-by-step explanation:
Hair Bulb
The hair bulb is the structure at the base of the hair root that surrounds the dermal papilla. It contains a layer of mitotically active basal cells called the hair matrix.
Hair Papilla
The hair papilla is a mass of connective tissue, blood capillaries, and nerve endings located at the base of the hair follicle.
Hair Root
The hair root is the part of the hair that is anchored in the follicle and lies below the surface of the skin.
Hair Shaft
The hair shaft is the part of the hair that is not anchored to the follicle and is exposed at the skin's surface.