Nerves of the Pelvis Flashcards
Iliohypogastric n.
Iliohypogastric (L1) sensory to skin over lowest dermatyome of anterior body wall
Ilioinguinal n.
ilioinguinal (L1): sensory to labial/scrotal region
Genitofemoral n.
genitofemoral (L1,L2): skin of proxmial thigh and labial/scrotal region
Lateral femoral cutaneous n.
lateral femoral cutaneous (L2, L3): skin over the lateral aspect of the thigh
Femoral n.
femoral (L2-4): skin of anterior thigh and muscles of anterior compatrtment of thigh
Obturator n.
obturator (L2-4): skin of medial thigh and muscles of medial compartment of thigh
Lumbosacral trunk
lumbosacral trunk (L4,5): takes lumbar innervation to sacral plexus
MERGED VENTRAL RAMI
Sciatic n.
sciatic (L4-S3): motor/sensory to posterior compartment of thigh and all of leg and foot.
Pudendal n.
pudendal (S2-4): sensory to perineum and external genitalia.
Which nerves are concerned with innervating the muscular floor of the pelvis?
Those arising from S2-4 (NOT the pelvic splanchnic portions of these vertebral levels but the somatomotor portions).
How is parasympathetic innervation distributed within the pelvis?
S2-4, via the pelvic splanchnic nn. (preganglionic parasympathetic fibers)
Where does the sympathetic innervation come from? Via what structure(s) does this sympathetic innervation arrive here?
The sympathetic trunk. The lumbar and sacral splanchnic nerves (NOT pelvic splanchnics). These are preganglionic sympathetic fibers.
What two plexuses are concerned with pelvic autonomic distribution?
Superior and inferior hypogastric plexuses.
What is the lumbosacral plexus composed of?
Ventral rami of T12-S4, Co create somatic plexuses
What is the sacral plexus composed of?
L4-S4 as the ventral rami exit the anterior sacral foramen.
