Pelvic Visceral Nervous System Flashcards
what do all pelvic viscera receive
both sympathetic and parasympathetic innervation
as the perineum is part of the body wall, what kind of innervation does it receive?
somatic innervation via the pudendal nerve
S2, 3, 4 keeps the….
penis off the floor —-> pudendal nerve
what levels do all preganglionic sympathetic cell bodies reside in the lateral horn?
T1 - L4
describe the preganglionic sympathetic pathway
lateral horn –> ventral horn –> ventral root –> mixed spinal nerve –> ventral ramus –> white ramus communicans –> paravertebral ganglion
in the pelvis, sympathetics headed to the body wall travel with what?
with the sacral and coccygeal ventral rami
for the majority of pelvic structures, where do the postganglionic sympathetics come from?
the hypogastric ganglion/plexus
what is the exception for the origin of the majority of pelvic structures/postganglionic sympathetics
the gonads –> they receive sympathetic postganglionics from the cranial mesenteric ganglion via the gonadal arteries
what does the parasympathetic system completely bypass?
sympathetic trunk
BECAUSE IT SYNAPSES IN THE WELL OF ORGAN
what are the sacral splanchnic nerves
sympathetic –> branches of the sympathetic chain
what are the pelvic splanchnic nerves
parasympathetic –> branches of the ventral rami
what do pelvic plexuses contain?
PREGANGLIONIC parasympathetics and POSTGANGLIONIC sympathetics
parasympathetics can’t synapse until in the wall of the organ
how does non-pain for the hindgut and pelvis travel?
follows the parasympathetic pathway back to the cns
how does pain for the hindgut and pelvis travel?
also follows the parasympathetic pathway back to the cns
how will pain from the gonads travel?
follows the sympathetic pathway to the cranial mesenteric ganglion
what do sympathetics do in the vesical plexus and rectal plexus?
maintain contraction of internal urethral/anal sphincter
what do parasympathetics do in the vesical plexus and rectal plexus?
inhibit contraction of internal urethral/anal sphincter
what do sympathetics do in the prostate plexus
causes ejaculation and vasoconstriction, resulting in remission of erection
also causes peristalsis of ductus deferens, seminal vesicles, and contraction of prostate gland
what do parasympathetics do in the prostate plexus
relaxation of smooth muscle and vasodilation to allow for phallic erection
what are erection and ejaculation controlled by?
both the visceral and somatic nervous systems
describe what happens in a flaccid phallus
parasympathetics are low, so the AV shunt is open, allowing blood to bypass capillaries so erectile tissues do not get engorged to maintain a flaccid phallus
describe what happens in an erect phallus
parasympathetics are high, so the AV shunt is closed, allowing blood to pool in the erectile tissues, which compresses draining veins, maintaining an erection
what is the female equivalent of the ischiocavernosus
constrictor vestibulae
what is the female equivalent of the bulbospongiosus
constrictor vulvae
what is the retractor clitoris constructed out of
bulbospongiosus
what ties the male
constriction by female constrictor vestibulae