This is a very intricate intertwining of postganglionic sympathetic, pre- and postganglionic parasympathetic nerve fibers as well as postganglionic parasympathetic neurons.
The braid is formed in front of the last lumbar vertebra (L5) by nerve fibers from the abdominal ganglia and the two boundary strands weaving together and making their way down into the pelvis in front of the sacrum (sacrum). The braid, which so far is also called the plexus hypogastricus superior or nervus presacralis, then divides into two smaller braids, one on the right and one on the left down in the pelvic cavity (plexus hypogastricus inferior dex. et sin.)
The braidwork continues to receive postganglionic sympathetic nerve fibers from the border cord. In addition, the spinal nerves S 2,3,4 lead preganglionic parasympathetic nerve fibers (nervi erigentes/nervi splanchnici pelvini) into the braids.
The postganglionic parasympathetic nerve cell bodies are more or less diffusely distributed in the braids or form ganglia adjacent to the target organs in the pelvis (bladder, lower part of the colon, rectum, uterus, etc.). Postganglionic nerve fibers then leave the braids and parasympathetic ganglia and enter the target organs to innervate glands and smooth muscle in the visceral walls and blood vessels.