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Pelvic splanchnic nerves or nervi erigentes are
splanchnic nerves The splanchnic nerves are paired visceral nerves (nerves that contribute to the innervation of the internal organs), carrying fibers of the autonomic nervous system ( visceral efferent fibers) as well as sensory fibers from the organs ( visceral a ...
that arise from sacral
spinal nerve A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the ...
s S2, S3, S4 to provide
parasympathetic The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of ...
innervation to the organs of the pelvic cavity.


Structure

The pelvic splanchnic nerves arise from the anterior rami of the sacral
spinal nerve A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the ...
s S2, S3, and S4, and enter the sacral plexus. They travel to their side's corresponding
inferior hypogastric plexus The inferior hypogastric plexus (pelvic plexus in some texts) is a network () of nerves that supplies the organs of the pelvic cavity. The inferior hypogastric plexus gives rise to the prostatic plexus in males and the uterovaginal plexus in femal ...
, located bilaterally on the walls of the rectum. They contain both preganglionic parasympathetic fibers as well as visceral afferent fibers. Visceral afferent fibers go to spinal cord following pathway of pelvic splanchnic nerve fibers. The
parasympathetic nervous system The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part o ...
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 Sacral splanchnic nerves are splanchnic nerves that connect the inferior hypogastric plexus to the sympathetic trunk in the pelvis. Structure The sacral sympathetic nerves arise from the sacral part of the sympathetic trunk, emerging anteriorly fr ...
, which arise from the sympathetic trunk and provide sympathetic efferent fibers.


Function

The pelvic splanchnic nerves contribute to the innervation of the pelvic and genital organs. The nerves regulate the emptying of the
urinary bladder The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine ente ...
, control opening and closing of the internal urethral sphincter, influence motility in the
rectum The rectum is the final straight portion of the large intestine in humans and some other mammals, and the gut in others. The adult human rectum is about long, and begins at the rectosigmoid junction (the end of the sigmoid colon) at the l ...
as well as sexual functions like
erection An erection (clinically: penile erection or penile tumescence) is a physiological phenomenon in which the penis becomes firm, engorged, and enlarged. Penile erection is the result of a complex interaction of psychological, neural, vascular, a ...
. In the distal 1/3 of the transverse colon, and through the sigmoid and rectum, and the
cervix The cervix or cervix uteri (Latin, 'neck of the uterus') is the lower part of the uterus (womb) in the human female reproductive system. The cervix is usually 2 to 3 cm long (~1 inch) and roughly cylindrical in shape, which changes during ...
in females, the pelvic splanchnic nerves supply parasympathetic function, including transmitting the sensation of pain. The proximal 2/3 of the transverse colon, and the rest of the proximal
gastrointestinal tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...
is supplied its parasympathetic fibers by the
vagus nerve The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and righ ...
.


Clinical significance

Damage to the sacral spinal nerve roots can cause
neurogenic bladder dysfunction Neurogenic bladder dysfunction, or neurogenic bladder, refers to urinary bladder problems due to disease or injury of the central nervous system or peripheral nerves involved in the control of urination. There are multiple types of neurogenic bladde ...
and fecal incontinence.


Society and culture

The pelvic splanchnic nerves are featured as a key plot point in " Parasites Lost", a 2001 episode of the American animated TV comedy ''
Futurama ''Futurama'' is an American animated science fiction sitcom created by Matt Groening for the Fox Broadcasting Company. The series follows the adventures of the professional slacker Philip J. Fry, who is cryogenically preserved for 1000 years ...
''; when protagonist
Philip J. Fry Philip J. Fry, commonly known by his surname, is a fictional character and the protagonist of the animated series ''Futurama''. He is voiced by Billy West using a version of his own voice as he sounded when he was 25. He is a slacker delivery b ...
is infected with parasitic worms, the rest of the crew use micro-droids to enter his body with the intention of tickling the pelvic splanchnic ganglion to trigger a convulsive bowel movement that they believe will expel the worms.


See also

*
Sacral splanchnic nerves Sacral splanchnic nerves are splanchnic nerves that connect the inferior hypogastric plexus to the sympathetic trunk in the pelvis. Structure The sacral sympathetic nerves arise from the sacral part of the sympathetic trunk, emerging anteriorly fr ...
* Coccygeal plexus


References


External links

* * * * () {{Autonomic Nerves