Preganglionic Connections of the Intramural Ganglia of the Urinary Bladder

The pelvic autonomic ganglia including the intramural ganglia of the urinary bladder, are connected with the lower thoracic and upper lumbar segments of the spinal cord through the splanchnic and hypogastric nerves and with the sacral segments through the pelvic nerves. The efferent fibers which enter the pelvic plexus on either side via the hypogastric nerve are mainly postganglionic sympathetic fibers, but include some preganglionic fibers of the thoraco-lumbar outflow. According to Langley and Anderson (1894, 1896) 1 and Stewart (1899) 2 some preganglionic fibers which enter the inferior mesenteric plexus do not terminate in this plexus but extend distalward in the hypogastric nerves. In spite of these reported observations, the pelvic autonomic ganglia quite generally have been regarded as related mainly to the parasympathetic division of the autonomic nervous system.

In an experimental anatomical study of the preganglionic connections of the ganglia in the pelvic plexus in the cat, Kuntz and Moseley (1936) 3 have demonstrated that some of these ganglia receive preganglionic fibers exclusively through the thoraco-lumbar outflow, some exclusively through the sacral outflow, and some through both the thoraco-lumbar and sacral outflows.

In the present study, cats have been used as the experimental animals, and the following operative procedures have been carried out under aseptic conditions. In one series, the pelvic nerve was sectioned bilaterally near its origin from the sacral nerves in order to insure degeneration of all preganglionic and visceral afferent sacral nerve components which enter the urinary bladder. In another series, the inferior mesenteric ganglia and both sympathetic trunks from the second lumbar segment caudalward were extirpated in order to insure degeneration of all preganglionic components of the thoraco-lumbar outflow which might reach the urinary bladder. When the animals were killed 18 to 24 days after operation, the urinary bladder was prepared for study by the pyridine silver method.