Tonofilaments-Cytokeratin Filaments

Using electron microscopy, the light microscopic images of intracellular tonofibrils  prove to be bundles of very fine filaments. The bundles are either strictly parallel or wavy bundles, which create the image of brush strokes in electron micrographs. Tonofibrils pervade especially the cells in the lower layers of the multilayered squamous epithelium. They line up in the direction of the tensile force. However, filament bundles also extend from the cell center to areas with many desmosomes. Tonofilament bundles in the epithelial cell of the vaginal portio uteri.

References

Kuehnel, W.(2003). Color Atlas of Cytology, Histology, and Microscopic Anatomy. 4^th edition . Institute of Anatomy Universitätzu Luebeck Luebeck, Germany . Thieme Stuttgar t · New York .