Pelvic splanchnic nerves

Nerve: Pelvic splanchnic nerves
Latin	nervi pelvici splanchnici nervi erigentes
From	S2-S4

Pelvic splanchnic nerves or nervi erigentes are splanchnic nerves that arise from sacral spinal nerves S2, S3, S4 to provide parasympathetic innervation to the hindgut.

Structure

The pelvic splanchnic nerves arise from the ventral rami of the S2-S4 and enter the sacral plexus. They travel to their side's corresponding inferior hypogastric plexus, located bilaterally on the walls of the rectum.

From there, they contribute to the innervation of the pelvic and genital organs. The nerves regulate the emptying of the urinary bladder and the rectum as well as sexual functions like erection.

They contain both preganglionic parasympathetic fibers as well as visceral afferent fibers.

The parasympathetic nervous system is referred to as the craniosacral outflow; the pelvic splanchnic nerves are the sacral component. They are in the same region as the sacral splanchnic nerves, which arise from the sympathetic trunk and provide sympathetic efferent fibers.

The proximal 2/3 of the transverse colon, and the rest of the proximal gastrointestinal tract is supplied its parasympathetic fibers by the vagus nerve. In the distal 1/3 of the transverse colon, and through the sigmoid and rectum, the pelvic splanchnic nerves take over.

See also

• sacral splanchnic nerves
• Coccygeal plexus

External links

• Pelvic+splanchnic+nerves at eMedicine Dictionary
• SUNY Labs 43:15-0107
• Anatomy at UMich autonomics_abdomen_module/abdomen_07
• Human anatomy at Dartmouth figures/chapter_32/32-6.HTM
• pelvis at The Anatomy Lesson by Wesley Norman (Georgetown University) (pelvicnerves)