To start with, I will provide you with some knowledge about the structure of hair. Hair is made up of two basic parts: The follicle, which is the actively growing root or base of a hair containing DNA and living cells, and the shaft, which is a strand of hair compose of a protein called keratin. The shaft is made up of the medulla (the central core of a hair fiber), the cortex (the region of a hair located outside of the medulla containing granules of pigment), and the cuticle (the tough outer covering of a hair composed of overlapping scales). The medulla is different from person to person. Some are continuous, some are fragmented, some aren’t there at all, and some are even doubled. There are also different types of cuticles, including imbricate, which is what humans have, coronal, which is what rodents have, and spinous, which is what animals such as cats have. With a macroscopic view of hair you can see differences in color, length, and where it is curly, wavy, or straight, but that only scratches the surface of what you can see on hair. With a microscopic view you can see the medullary index (the ratio of diameter of the medulla to the diameter of the hair), cuticle type, cortex color, diameter of the hair, and much more.…