Pelvic Visceral Nervous System

Question 1

what do all pelvic viscera receive

Answer 1

both sympathetic and parasympathetic innervation

Question 2

as the perineum is part of the body wall, what kind of innervation does it receive?

Answer 2

somatic innervation via the pudendal nerve

Question 3

S2, 3, 4 keeps the….

Answer 3

penis off the floor —-> pudendal nerve

Question 4

what levels do all preganglionic sympathetic cell bodies reside in the lateral horn?

Answer 4

T1 - L4

Question 5

describe the preganglionic sympathetic pathway

Answer 5

lateral horn –> ventral horn –> ventral root –> mixed spinal nerve –> ventral ramus –> white ramus communicans –> paravertebral ganglion

Question 6

in the pelvis, sympathetics headed to the body wall travel with what?

Answer 6

with the sacral and coccygeal ventral rami

Question 7

for the majority of pelvic structures, where do the postganglionic sympathetics come from?

Answer 7

the hypogastric ganglion/plexus

Question 8

what is the exception for the origin of the majority of pelvic structures/postganglionic sympathetics

Answer 8

the gonads –> they receive sympathetic postganglionics from the cranial mesenteric ganglion via the gonadal arteries

Question 9

what does the parasympathetic system completely bypass?

Answer 9

sympathetic trunk

BECAUSE IT SYNAPSES IN THE WELL OF ORGAN

Question 10

what are the sacral splanchnic nerves

Answer 10

sympathetic –> branches of the sympathetic chain

Question 11

what are the pelvic splanchnic nerves

Answer 11

parasympathetic –> branches of the ventral rami

Question 12

what do pelvic plexuses contain?

Answer 12

PREGANGLIONIC parasympathetics and POSTGANGLIONIC sympathetics

parasympathetics can’t synapse until in the wall of the organ

Question 13

how does non-pain for the hindgut and pelvis travel?

Answer 13

follows the parasympathetic pathway back to the cns

Question 14

how does pain for the hindgut and pelvis travel?

Answer 14

also follows the parasympathetic pathway back to the cns

Question 15

how will pain from the gonads travel?

Answer 15

follows the sympathetic pathway to the cranial mesenteric ganglion

Question 16

what do sympathetics do in the vesical plexus and rectal plexus?

Answer 16

maintain contraction of internal urethral/anal sphincter

Question 17

what do parasympathetics do in the vesical plexus and rectal plexus?

Answer 17

inhibit contraction of internal urethral/anal sphincter

Question 18

what do sympathetics do in the prostate plexus

Answer 18

causes ejaculation and vasoconstriction, resulting in remission of erection

also causes peristalsis of ductus deferens, seminal vesicles, and contraction of prostate gland

Question 19

what do parasympathetics do in the prostate plexus

Answer 19

relaxation of smooth muscle and vasodilation to allow for phallic erection

Question 20

what are erection and ejaculation controlled by?

Answer 20

both the visceral and somatic nervous systems

Question 21

describe what happens in a flaccid phallus

Answer 21

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

Question 22

describe what happens in an erect phallus

Answer 22

parasympathetics are high, so the AV shunt is closed, allowing blood to pool in the erectile tissues, which compresses draining veins, maintaining an erection

Question 23

what is the female equivalent of the ischiocavernosus

Answer 23

constrictor vestibulae

Question 24

what is the female equivalent of the bulbospongiosus

Answer 24

constrictor vulvae

Question 25

what is the retractor clitoris constructed out of

Answer 25

bulbospongiosus

Question 26

what ties the male

Answer 26

constriction by female constrictor vestibulae