Lecture 7: Gluteal Region + Lumbosacral Plexus Flashcards
What is the nerve network supplying the lower extremities with sensory and motor nerves?
Lumbosacral plexus
Where does the lumbosacral plexus originate?
Ventral primary rami of spinal nerves including L1-S3
What 9 branches of the lumbosacral plexus emerge in the gluteal region?
Superior gluteal n. Inferior gluteal n. Nerve to piriformis Sciatic n. Posterior femoral cutaneous n.
Motor nerves to quadratus femoris, inferior and super gemelli, and obturator internus
Where does the sciatic n. originate?
Spinal cord levels L4-S3
What does the sciatic n. pass through to get into the gluteal region?
Greater sciatic foramen
What are the 2 divisions of the sciatic n.?
Tibial division
Peroneal division
Which division of the sciatic n. supplies the hamstring muscles in the posterior thigh?
Tibial division
The tibial division of the sciatic n. passes through what to get into the posterior compartment of the leg?
Popliteal fossa
What nerve supplies all muscles in the posterior compartment of the leg?
Tibial n. (Branch of sciatic n.)
The tibial division of the sciatic n. eventually enters the tarsal tunnel and divides to supply the sole of the foot as what 2 nerves?
Lateral plantar n.
Medial plantar n.
The peroneal division of the sciatic n. begins as what major nerve positioned next to the head of the fibula?
Common peroneal n. (Fibular)
Why is the position of the common peroneal n. a potential issue?
Its position next to the head of the fibula makes it susceptible to traumatic injury
What are the 2 branches of the common peroneal n. and what do they supply?
Superficial peroneal n. - lateral compartment of the leg
Deep peroneal n. - anterior compartment of the leg
Where does the posterior femoral cutaneous n. originate?
Spinal cord levels L2-L4
The posterior femoral cutaneous n. passes under what structure to enter the anterior thigh?
Inguinal ligament
What is the final branch of the posterior femoral cutaneous n.?
Saphenous n.
Where does the obturator n. originate?
Spinal cord levels L2-L4
What does the obturator n. pass through to get into the medial thigh?
Obturator foramen in the obturator membrane
The obturator n. supplies all muscles in the medial compartment of the thigh except which one? What nerve supplies that muscle?
Pectineus - femoral n.
The lumbar aspect of the lumbosacral plexus is located in the lumbar region within what muscle?
Psoas major m. (Anterior to transverse processes of lumbar vertebrae)
The lumbar aspect of the lumbosacral plexus is formed by the _______ rami of L__-__
Anterior; L1-4
[also receives contributions from T12]
What are the 6 major peripheral nerves of the lumbar aspect of the lumbosacral plexus?
Iliohypogastric n. Ilioinguinal n. Genitofemoral n. Lateral cutaneous n. of the thigh Obturator n. Femoral n.
The iliohypogastric n. is the first major branch of the lumbar plexus. It runs to the iliac crest, across the _____ ______ muscle, and perforates the _____ ______ muscle where it divides into its terminal branches
Quadratus lumborum
Transversus abdominis
What are the roots of the iliohypogastric n.?
L1 (with contributions from T12)