INNERVATION OF THE GENITOURINARY SYSTEM
The parts of the genitourinary system that are in the abdomen
receive their nerve supply from the autonomic nervous system by means of both sympathetic
and parasympathetic pathways. The pelvic urinary organs and genitalia are supplied
by somatic in addition to autonomic nerves. Table
54-1
summarizes the pain conduction pathways and spinal levels of the genitourinary
system.
Kidney and Abdominal Ureter
Sympathetic nerves to the kidney originate as preganglionic fibers
from the eighth through the first lumbar segments and converge at the celiac plexus
and aorticorenal
ganglia ( Fig. 54-1
). Postganglionic
fibers to the kidney arise mainly from the celiac and aorticorenal ganglia. Some
sympathetic fibers may reach the kidney by way of the splanchnic nerves. Parasympathetic
input is from the vagus nerve.[2]
Sympathetic fibers
to the ureter originate from the 10th thoracic through the 2nd lumbar segments and
synapse with postganglionic fibers in the
Figure 54-1
Autonomic and sensory innervation of the kidney and ureters.
Solid line, preganglionic fibers; dashed
line, postganglionic fibers; dotted line,
sensory fibers. (From Gee WF, Ansell JF: Pelvic and perineal pain of urologic
origin. In Bonica JJ [ed]: The Management of Pain,
2nd ed. Philadelphia, Lea & Febiger, 1990, pp 1368–1378.)
aorticorenal and superior and inferior hypogastric plexus. Parasympathetic input
is from the second through fourth sacral spinal segments.[2]
Nociceptive fibers travel along the sympathetics to the same spinal segments. Pain
from the kidney and ureter is therefore referred mainly to the somatic distribution
of the 10th thoracic through the 2nd lumbar segments, namely, the lower part of the
back, flank, ilioinguinal region, and scrotum or labia. Effective neural block of
these segments is necessary to provide adequate analgesia or anesthesia.
