A Study About Development of The Reticular Fibers Under the Nail in Human Embryos.
Yoko Kishi, Naoshi Hashimoto.
This study demonstrates the formation of reticular fibers under fetus nail during the nail development. The seventy-one digits of human fetus had been kept in the buzan stein in the department of the second Anatomy since 1970. They were amputated to measure the length and checked the shape. Then paraffin fixation method was performed. While the nail was formed, we observed using H-E stein and PAM stein how the reticular fibers under the nail were produced. In the early stage of nail formation, the basal layer of the epidermis was positive in PAM stein from matrix and nail bed. Under the basal layer the reticular fibers also were dyed like an arched bridge from the tip of distal phalanx before the matrix primordium was formed. Within the period after the matrix proximordium was produced, the reticular fibers developed under the nail bed especially at the two parts. One part is between the distal phalanx and the matrix primordium. The other is between the tip of distal phalanx and the distal groove. These fibers became thick gradually. In our study, the nail bed and matrix were constantly positive in PAM stein during nail formation. It shows that the nail bed and matrix make the reticular fibers during the nail developmental stage. The ridged connection between the tip of the nail and the distal phalanx is made by the reticular fibers.View pdf