So the hair shaft is made almost entirely of dead keratin-filled cells. The melanin is transferred to the cells in the hair shaft. Different proportions of brown-black, yellow and reddish melanin combine to produce all varieties of hair color from blond to black. Gray or white hair results from a decrease in melanin production. The melanin is replaced by air bubbles in the hair shaft.
Hair follicles are normally at a slight angle in the skin.
The arrector pili muscles are regulated by the nervous system and are activated by cold external temperatures or fright. They detect if a hair shaft is moved. A NAIL consists of a plate of hard, keratinized epidermal cells that form a clear protective covering on the dorsal surface of the distal part of a finger or toe. Nails protect the ends of the digits from trauma. Our fingernails help us to grasp and manipulate small objects.