Eveything about hair!
Basic Structure of Hair:
The hair shaft has three parts, the cuticle, the cortex, and the medulla. The cuticle is the clear outside covering of the hair shaft. It is made up of tough overlapping scales. The cortex is made up of keratin molecules. Keratin is tough protein made up of about 20 different amino acids. In the cortex is the pigment that makes our hair black, brown, blonde, or red. If we didn't have that pigment our hair would be gray or white. And, that's the cause of gray and white hair. The medulla is a row of cells that run along the center of the cortex. It sometimes appears dark or translucent depending on whether there is air, liquid, or pigment in it. Human hair generally has no medulla or one that is fragmented.