Innervation Of The Pelvis

Front 1

what plexuses contribute to the somatic nervous system for innervating the pelvis?

Back 1

lumbar plexus (T12) L1 to L4
sacral plexus L5-S4
(the lumbosacral trunk -- L4/L5 -- joins these two)
coccygeal plexus S4 to Co

Front 2

Contributions from what autonomic fibers are made to innervate the visceral nervous system of the pelvis?

Back 2

sympathetics from abdomen
sympathetics from sacral chain
parasympathetics from sacral lateral horn of spinal cord
visceral efferents

Front 3

what are the five branches of the pudendal nerve?

Back 3

inferior rectal
deep perineal
superficial perineal
posterior scrotal (labial)
dorsal nerve of penis (clitoris)

Front 4

the anterior rami of S2 and S3 emerge between the digitation of what two muscles?

Back 4

piriformis and coccygeus

Front 5

the sciatic nerves is formed by what two nerves?

Back 5

common fibular and tibial

Front 6

what vertebral levels contribute to the pudendal nerve?

Back 6

somatic nerve from the sacral plexus ventral rami S2, 3, 4

Front 7

what does the superior gluteal artery serve as a good landmark for?

Back 7

it lies between the lumbosacral trunk and S1

Front 8

Course of the pudendal nerve

Back 8

exits true pelvis via greater sciatic foramen to gluteal region (below piriformis)
exits gluteal region via leser sciatic foramen to perineum and runs in pudendal canal to perineal membrane

Front 9

What does the pudendal nerve innervate?

Back 9

1. provides inferior rectal branches to anal traingle to external anal sphincter
2. provides posterior scrotal/labial branches before entering the deep pouch
3. supplies external urethral sphincter muscle in deep pouch
4. supplies branches to bulbospongiosus and ischiocavernosus muscles
5. supplies sensation to the phallus as the dorsal nerve of the clitoris or penis

Front 10

what nerves supply the external anal sphincter and are involved in the motor limb of the anal wink reflex?

Back 10

inferior rectal branches of the pudendal nerve

Front 11

what nerve innervates the following:

obturator internus
piriformis
pelvic diaphragm

Back 11

obturator has its own nerve
piriformis does too (comes off sacral plexus)
pelvic diaphragm has a sacral nerve branch

Front 12

the muscles of the deep perineal pouch are supplied by which nerves?

Back 12

deep perineal branch of the pudendal nerve

Front 13

how is an erection achieved?

Back 13

erectile muscles (somatic!) like the bulbospongiosus and ischiocavernosus are innervated by the superficial branch of the pudendal nerve

they hydraulically push blood to distal phallus increasing turgidness and pulsatility of ejaculation

Front 14

what nerves innervate the external genitalia?

Back 14

branches of the lumbar plexus:
ilioinguinal (ant scrtoal and labial)
genital branch of genitofemoral

branches of sacral plexus
pudendal (post scrotal/labial)
dorsal branch of clitoris penis

(remember pics with ares outlined in yellow and green)

Front 15

what structures exit the greater sciatic notch superior to the piriformis?

Back 15

superior gluteal v/a/n

Front 16

what structures exit the greater sciatic notch inferior to the piriformis?

Back 16

inferior gluteal v/a/n
sciatic n
internal pudendal v/a
pudendal n

Front 17

what doe the subinguinal hiatus give entry to?

Back 17

entry from false pelvis to thigh

Front 18

what type of nerves are responsible for erection?

Back 18

para, result from decreased venous return

Front 19

what type of nerves are resonsible for orgasm (contraction of vas deferens, internal urethral sphincter contraction to prevent retrodgrade ejaculate or urination)?

Back 19

symps

Front 20

what plexuses of autonomics and visceral afferents are found around various organs of the pelvis?

Back 20

vessicular plexus (around bladder)
prostatic plexus
cavernous nerves
uterovaginal plexus
rectal plexus

Front 21

what nerves to erectile bodies are often damaged during prostate resection resulting in impotence?

Back 21

cavernous nerves

Front 22

how far do vagus parasymps extend down the abdomen?

Back 22

as far as the end of the midgut

Front 23

what symps supply celiac trunk?

Back 23

greater splanchnic T5-9

Front 24

what symps supply SMA?

Back 24

lesser splanchnic T10-11

Front 25

what symps supply IMA?

Back 25

lumbar splanchnics

Front 26

what para nerves supply the hindgut?

Back 26

pelvic splanchnic

Front 27

what are the three sources of autonomics to the pelvis?

Back 27

pelvic splanchnics
sacral splanchnics
superior hypogastric plexus (sympathetics left over in abdomen...source from lumbar chain aortic plexus)

Front 28

what nerves serve the levator ani?

Back 28

sacral nerves

Front 29

what nerve supplies the external anal sphincter?

Back 29

pudendal (inferir rectal branchn)