The hair like any other part of the body is supported by the blood. As the blood brings oxygen and nutrients into the papilla area it promotes cellular activity for the hair, and as these cells reproduce, they build a flexible substance called Keratin (hair). As the hair grows in the follicle, it is then lubricated by the sebaceous gland that secretes oil in the follicle, which coats the hair for smooth growth and provides luster and sheen.