MSK: lumbosacral plexus Flashcards
Which major branches of the lumbar plexus pass medial to psoas major?
Obturator and lumbosacral trunk.
Which major branches of the lumbar plexus pass lateral to psoas major?
Femoral nerve
iliohypogastric nerve
Ilioinguinal nerve
Lateral cutaneous nerve of the thigh (lateral femoral cutaneous nerve)
Where does the sacral plexus form?
Forms within the pelvic cavity, anterior to piriformis.
What does the sacral plexus supply?
- Pelvic region
- Gluteal region
- Perineal region
- Lower limb
Which two nerves form the sciatic nerve?
Tibial and common peroneal nerve.
What are the nerve roots of the obturator nerve? Which plexus does it originate from?
L2-L4 (lumbar plexus)
What are the nerve roots of the lumbosacral trunk? Which plexus does it originate from?
L4-5 (both - it joins them together).
What are the nerve roots of the femoral nerve? Which plexus does it originate from?
L2-4 (lumbar plexus).
What are the nerve roots of the iliohypogastric nerve? Which plexus does it originate from?
L1 (lumbar plexus).
What are the nerve roots of the ilioinguinal nerve?
L1 (lumbar plexus).
What are the nerve roots of the lateral cutaneous nerve of the thigh (also called the lateral femoral cutaneous nerve)? Which plexus does it originate from?
L2-L3 (lumbar plexus).
What are the nerve roots of the superior gluteal nerve? Which plexus does it originate from?
Dorsal divisions of L4-S1 (sacral plexus).
What are the nerve roots of the inferior gluteal nerve? Which plexus does it originate from?
Dorsal divisions of L5-S2 (sacral plexus).
What are the nerve roots of the common peroneal nerve? Which plexus does it originate from?
Dorsal divisions of L4-S2 (Sacral plexus).
What are the nerve roots of the tibial nerve? Which plexus does it originate from?
Ventral divisions of L4-S3 (sacral plexus).
