Pelvis Somatic Nerves Flashcards
The obturator nerve is part of what plexus?
lumbar
Obturator n arises from which lumbar cord segments?
L2-4
Obturator n enters the pelvis where?
along medial border of psoas major m
Where does the obturator n pass?
passes along the lateral wall of pelvis to obturator canal,
What is the obturator canal?
an opening in obturator membrane that otherwise fills obturator foramen
Where does the obturator nerve exit the pelvis?
via obturator canal with obturator AV
What does the obturator n innervate?
adductors of medial thigh
Compression of obturator nerve during childbirth causes what?
painful spasms in thigh adductors and sensory deficits in the medial thigh
What ventral rami make up the lumbosacral trunk?
L4-5
The lumbosacral trunk is medial to what structure?
psoas major m
lumbosacral trunk passes anterior to ?
ala of sacrum to join sacral plexus
What nerves make up the sacral plexus?
sciatic, pudendal, superior gluteal, inferior gluteal
the sacral plexus lies on the pelvic surface of which muscle?
piriformis
What rami make up the sacral plexus?
L4-S4
most branches of sacral plexus exit pelvis via?
greater sciatic foramen
What is the largest and broadest nerve in teh body?
sciatic
Sciatic nerve is formed by what ventral rami?
L4-S3, converge on anterior surface of piriformis m
Where does the sciatic nerve exit?
exits pelvis inferior to piriformis m via greater sciatic foramen –> enters gluteal region and descends thru posterior thigh
What does the sciatic nerve innervate?
posterior thigh and entire leg and foot
What is the main motor and sensory nerve of perineum?
pudendal n
pudendal n is the primary sensory innervation of ?
external genitalia
What does the pudendal nerve terminate as?
dorsal n of penis/clitoris?
The pudendal n is formed by anterior division of what ventral rami?
S2-S4
Where does the pudendal nerve exit?
exits pelvis with internal pudendal AV via greater sciatic foramen
The pudendal nerve T/F passes anterior to the ischial spine and over sacrospinous lig
F, passes posterior
How does the pudendal nerve enter perineum?
by passing thru lesser sciatic foramen
Superior gluteal n arises from posterior division of which ventral rami?
L4-S1
How does the superior gluteal n exit the pelvis?
superior to piriformis via greater sciatic foramen
Does the superior gluteal n parallel the superior gluteal AV
yep
What does the superior gluteal n supply?
glut med, glut min, TFL
Inferior gluteal n arises from posterior division of which ventral rami?
L5-S2
How does the inferior gluteal n exit the pelvis?
inferior to piriformis via greater sciatic foramen, parallels inferior gluteal AV
what does the inferior gluteal n innervate?
glut max
What ventral rami make up the coccygeal plexus?
small network arising from S4-S5 ventral rami
Where can you find the coccygeal plexus?
on pelvic surface of coccygeus m
What does the coccygeus plexus n innervate?
coccygeus m and levator ani m and skin between coccyx and anus
