The topography of rat submandibular gland parenchyma as observed with S.E.M.

The parenchymal components of rat submandibular gland were examined by scanning electron microscopy after removal of the stromal connective tissue by acid hydrolysis and/or enzymatic digestion. Secretory acini have polymorphous topographies but usually consist of three to five truncated lobes emanating from a common hilus. They have a mean volume of about 33,000 micrometers3. Myoepithelial cells are associated with the deeper acini of the gland where they cover congruent to 54% of the surface area of their allied acini. Each flattened myoepithelial cell has a central perikaryon that gives rise to four or five broad primary processes that bifurcate two or three times to produce a total complement of 20 to 40 terminal processes per cell, each 0.5 micrometer to 1.7 micrometers wide. The terminal processes of adjacent myoepithelial cells tend to slightly overlap and to attach to each other by desmosomes forming a network over adjacent acini. The components of the duct system are examined and each characterized by salient features as observed with the SEM.