The thick, club-shaped structure that forms the lower part of the hair root is known as what?

The thick, club-shaped structure that forms the lower part of the hair root is known as the hair bulb. The hair bulb is the living part of the hair and is located at the base of the hair follicle, where it surrounds the dermal papilla. The dermal papilla contains blood vessels that nourish the hair and is essential for hair growth. The hair bulb is crucial for the production and growth of hair, as it contains stem cells that contribute to the formation of hair strands. Understanding the structure and function of the hair bulb is important for estheticians, as it can influence hair health and treatments related to hair growth.