Innervation of the cat ureter. An experimental study.

Innervation of the ureter was studied by fluorescent microscopy using glyoxylic methods and by electron microscopy in the normal state and after extirpation of hypogastric ganglia. According to the morphology of the vesicle population, four groups of nerve processes could be distinguished: Type a with a dominant population of small agranular vesicles; Type b with a large number of small granular vesicles; Type c with 80 to 120 nm granulated vesicles; Type d with large 150 to 250 nm neurosecretory vesicles. After extirpation of the hypogastric ganglia, degenerated nerve terminals could be found in all the layers of the ureter, but a few fluorescent fibres could be observed in the muscle layers, too. It is assumed that most of the fluorescent fibres originate from the hypogastric ganglia and the others from the local neurons of from the spinal ganglia. These nerve processes act directly on the smooth muscle cells.