Superior hypogastric plexus

Origin and course

The superior hypogastric plexus is a primary retroperitoneal structure located in the midline of the lower abdomen. More specifically, it is situated anterior to the vertebral body of the inferiormost lumbar vertebrae (L5) and the bifurcation of the abdominal aorta, between the left and right common iliac arteries. It is formed by nerve fibers that originate from the three main sites:

• Aortic plexus
• Lumbar splanchnic nerves (L3, L4)
• Pelvic splanchnic nerves (S2-S4)

These contributing nerve fibers interconnect in the plexus together with the visceral afferent fibers. Nerve impulses are carried out of the plexus by a series of branches that usually convey information to other subsidiary nerve plexuses.

Branches and innervation

The two main branches that carry information to and out of the superior hypogastric plexus are the left and right hypogastric nerves. The hypogastric nerves carry sympathetic fibers from the superior hypogastric plexus to the inferior hypogastric plexus. At the same time, they carry parasympathetic fibers from the inferior hypogastric plexus to the superior hypogastric plexus.

The superior hypogastric plexus also gives off several smaller branches which convey innervation to the ureteric, gonadal and common iliac nerve plexuses, as well as the mesentery of the rectum (mesorectum) which accompany the superior rectal artery.

The prime function of the superior hypogastric plexus is to carry autonomic innervation to and receive visceral afferent fibers from the pelvic viscera and the distal bowel. More specifically, the superior hypogastric plexus provides the innervation for the distal rectum, distal portion of ureter, urinary bladder, reproductive tract and associated accessory glands, and blood vessels in both sexes. In males, it contributes to the innervation of the epididymis, ductus deferens, prostate and seminal vesicles. In females, it innervates the ovaries, uterine tubes, uterus and vagina. For this reason, the plexus plays a key role in continence (urinary and fecal) and the maintenance of normal sexual function, including erection and ejaculation.