What is a medulla? what do forensic scientists use this for?

medulla is a set of cells that runs through a hair.

Explanation:

The medulla is typically different depending on the species that the hair came from, which makes it one way to distinguish between animal and human hair. Forensic scientists may also look at the shape and color of pigment in the hair and whether or not the hair has been dyed or bleached. As hair grows about one centimeter a month, it may be possible to determine how long it has been since the hair has been dyed or bleached by looking at the natural end of the hair. Forensic scientists also examine hair for any abnormalities or deficiencies that may help them determine whom the hair came from.