Rectal Plexus

Description

Centered on the distal large bowel, the rectum and anal canal sit in the midline, with a dense rectal plexus draped circumferentially along the posterolateral rectal wall and into the mesorectal connective tissue. Sympathetic fibers descending as hypogastric nerves converge from a superior and lateral direction, while parasympathetic pelvic splanchnic nerves approach from the inferolateral pelvis to intermix within the pelvic plexus before distributing to the rectum. Fine branches track anteriorly toward the prostatic region and posteriorly toward the presacral space, forming an autonomic network that parallels accompanying vessels in the perirectal fascia. A tight web. That anatomic arrangement matters in total mesorectal excision and other rectal cancer operations, where dissection in the wrong plane risks injury to the hypogastric nerves, pelvic plexus, or neurovascular bundles and can translate directly into postoperative urinary retention, erectile dysfunction, and impaired rectal sensation. The same plexiform course explains why pelvic radiotherapy and locally advanced tumors can produce mixed bowel, bladder, and sexual symptoms, and why careful nerve-sparing technique tracks the posterolateral rectal surface while respecting the presacral fascia. Autonomic injury is rarely isolated. Use this illustration for teaching pelvic autonomic anatomy in colorectal surgery, urology, and anatomy lab curricula, and for figures in chapters on rectal cancer staging, nerve-sparing TME, and functional outcomes after pelvic surgery; it also suits patient-facing education when explaining expected bowel and sexual side effects in men. Anatomical accuracy verified by SciePro's Medical Advisory Board.