Final answer:
The hair root anchors the hair to the skin cells and is part of the hair located at the bottom of the follicle. The hair matrix within the root is where cell division occurs, leading to hair growth, with the hair papilla providing necessary nutrients and nerve endings.
Step-by-step explanation:
The hair root is the part of the hair located at the bottom of the follicle below the surface of the skin, which anchors the hair to the skin cells. The hair bulb forms the lowest part of the hair root and is where new cells are produced, leading to hair growth, making it a critical component of the hair follicle structure. These cells at the base of the hair root are known as the hair matrix, where active cell division takes place, and this process is responsible for creating the hair shaft that emerges from the skin's surface.
The living cells within the hair root transform into the dead, keratinized cells that make up the hair shaft. Therefore, while the hair shaft is considered dead and contains no biochemical activity, the hair root contains living keratinocytes important for hair growth. Surrounding the hair bulb is the hair papilla, which is rich in blood capillaries and nerve endings providing the nutrients and signals necessary for hair growth.