Quick Facts
Sympathetic Contribution: Aortic plexus, lumbar and sacral splanchnic nerves.
Parasympathetic Contribution: Pelvic splanchnic nerves.
Course: Postganglionic sympathetic axons descend, usually just left of the midline, from the bifurcation of the aorta, to the sacral promontory. Preganglionic axons ascend from the pelvis from the inferior hypogastric plexus.
Sympathetic Supply: Postganglionic sympathetic fibers follow the course of the common, internal, and external iliac arteries and their branches, the ureter, and ductus deferens to supply the pelvic organs.
Parasympathetic Supply: Pelvic splanchnic nerves provide preganglionic parasympathetic axons to the bladder, rectum, uterus, vagina, gonads, perineum, genital ducts, external genitalia, and inferior ureter.
Contributing Nerves
The superior hypogastric plexus receives sympathetic axons originating in the first or second lumbar nerve (L1 or L2) that pass through the aortic plexus, lumbar splanchnic, and sacral splanchnic nerves. Most synapse in the aortic plexus, the inferior mesenteric, or lumbar and sacral sympathetic ganglia before becoming part of the superior hypogastric plexus. Pelvic splanchnic nerves (S2-S4) contribute some preganglionic axons that ascend in, or in close association with, the superior hypogastric plexus.
Course
The superior hypogastric plexus is a loosely organized, unpaired structure that passes close to the midline from the aortic bifurcation, inferiorly along the anterior surface of the body of fifth lumbar (L5) vertebra, across the sacral promontory and into the true pelvis. Here it divides into right and left inferior hypogastric nerves. It contains primarily descending, sympathetic, as well as some ascending parasympathetic axons.
Branches
The superior hypogastric plexus contributes fibers to subplexuses associated with nearby arteries and ducts, including the common iliac, internal iliac, gonadal and ureteric plexuses. Those axons that do not peel off from these subplexuses continue inferiorly along the internal surface of the sacrum. Here the plexus divides into right and left inferior hypogastric plexuses.
Supplied Structures
The superior hypogastric plexus supplies sympathetic innervation of mostly extrapelvic structures, including the inferior ureter, gonads, and hindgut (superior rectum, sigmoid, descending, and left half to one third of the transverse colon). It may also include some pelvic innervation, although most of these travel within the hypogastric nerve and inferior hypogastric plexus. A minority of pelvic splanchnic axons pass along the inferior and superior hypogastric plexuses, continuing retroperitoneal to join distal inferior mesenteric vascular branches to the midgut. The majority of these descend with the superior rectal arteries and contribute to the inferior mesenteric plexus.
List of Clinical Correlates
—Superior hypogastric nerve block
