Quantitation of normal human hair pigmentation by electron microscopy

The study described the presence of holes in the endocuticle, inter-macrofibrillar matrix, and cell membrane complex of mature hair fibers, which were absent in hair follicles. It suggested that these holes likely developed due to daily hair care actions and the removal of extractable substances. The researchers found that cell remnants in young hair within the follicle were located in the same regions and had the same dimensions as the holes in mature fibers, indicating a possible relationship between cell remnants and hole formation.