The complementary structure of the superficial and deep surfaces of the cells lof the stratum corneum of the hard palate in the rat

The supeerficial and deep surfaces of the cells of the stratum corneum from the hard palate of the rat were examined in the scanning electron mictroscope. The appearances were compared with those seen in thin sections. In the scanning electron microscope, the superficial surface of each epithelial cell, whether it was situated on the exposed surface or more deepley within the epithelium, had a honeycomb surface pattern of inteerconnecting ridges surrounding depressions. Lateral cell boundaries consisted of two ridges separated by a gap, and the imprints of the edges of the overlying cells were formed by single raised ridges which crossed on to adjacent cells. The deep surface of the cells was covered by microvilli, a deepo groove separated teh margins of adjacent cells, and the imprints of the cell boundaries of the underlying cells were formed by shallower grooves which also crossed on to adjacet cells, The sectionaal appearance of the stratum corneum, as seen in the transmissison electron microscope, confirmed that the cells at different levels overlapped. It also confirmed that the microvilli and grooves on teh deepo surface of the cells were truly complementary and intimately related to the depressions and ridges on the superficial surfaces of opposing cells.