Unit 5 lumbosacral plexus Flashcards
What makes up the lumbar plexus?
VPR from L1-L4
Also, in 50% of people there is also a contribution of T12 VPR
Where is lumbar plexus?
under psoas major muscle
Divisions of lumbar plexus
Both anterior and posterior divisions. Most nerves branch from these divisions.
Some nerves, however, branch directly from the VPR
Nerves from lumbar plexus that come directly off the VPR?
subcostal nerve
iliohypogastric nerve
ilioinguinal nerve
genitofemoral nerve
subcostal nerves comes from?
T12 VPR
Iliohypogastric nerve comes from?
L1 VPR
ilioinguinal nerve comes from?
L1VPR
Genitofemoral nerve comes from?
L1- L2 VPR
nerves from posterior division of lumbar plexus?
lateral femoral cutaneous nerve
femoral nerve
lateral femoral cutanesous nerves comes from?
L2-L3
femoral nerve comes from?
L2-L4
nerves from Ant. division of lumbar plexus?
obturator nerve
accessory obturator nerve
where does obturator nerve originate?
L2-L4
where does accessory obturator nerve originate?
L3-L4
how often is accessory obturator nerve present?
9%
what does acessory obturator nerve supply when present?
pectineous muscle
What forms sacral pleuxs?
ventral primary rami of L4-S4
how does sacral plexus divide?
all VPR form anterior and posterior divisions
What makes up the lumbosacral trunk?
L4 L5 and S1 VPR
distal continuation of lumbosacral trunk?
sciatic nerve
What forms sacral plexus?
S1-S4 VPR
nerves from ant. division of sacral plexus?
tibial nerve
post. femoral cutaneous nerve
Pudendal
pelvic splanchnic nerve
n. to levator ani
where does tibial nerve originate?
ant division of L4-L5 and S1-S3
where does post femoral cutaneous nerve originate?
ant. division of S2-S3
post. divisions of S1-S2
where does pudendal nerve originate?
ant. divisions of S2-S4
where does pelvic splanchnic nerve originate?
ant. divisions of S2-S4
where does levator ani originate?
ant. divisions of S3-S4
function of tibial nerve?
motor to post let and hamstring
sesory/motor to plantar surface of foot
function post. femoral cutaneous nerve>
sensory to post thigh
function of pudendal nerve?
sensory to the external genitalia,
motor to urethral and anal sphincters
fucntion of pelvic splanchnic nerve?
parasymphathetic to pelvic viscera
function of levator ani?
make up the pelvic diaphragm
nerves from post. division of sacral plexus?
common peroneal nerve
post femoral cutaneous nerve
what nerve comes from both ant. and post. divisions of sacral plexus?
post femoral cutaneous nerve
where does common peroneal nerve originate?
post divisions of L4-L5 S1-S2 VPR
function of common peroneal nerve?
motor to ant leg and dorsal surgace of the foot, hamstring muscle
sensory to dorsal surface of the foot
