Glossary

anagen phase   The initial growth phase during which the hair follicle actively produces hair.

catagen phase   A transition stage between the anagen and telogen phases of hair growth.

cortex   The main body of the hair shaft.

cuticle   The scale structure covering the exterior of the hair.

follicular tag   A translucent piece of tissue surrounding the hair’s shaft near the root that contains the richest source of DNA associated with hair.

macromolecule   A molecule with a high molecular mass.

manufactured fibers   Fibers derived from either natural or synthetic polymers.

medulla   A cellular column running through the center of the hair.

mitochondrial DNA   DNA present in small structures (mitochondria) outside the nucleus of a cell. Mitochondria supply energy to the cell. This form of DNA is inherited maternally (from the mother).

molecule   Two or more atoms held together by chemical bonds.

monomer   The basic unit of structure from which a polymer is constructed.

natural fibers   Fibers derived entirely from animal or plant sources.

nuclear DNA   DNA that is present in the nucleus of a cell and that is inherited from both parents.

polymer   A substance composed of a large number of atoms that are usually arranged in repeating units.

telogen phase   The final growth phase in which hair naturally falls out of the skin.