LE blocks Flashcards
lumbar plexus originates from anterior rami of
L1-L4
sacral plexus originates from posterior rami of
L4-S4
draw the lumbar plexus
draw the sacral plexus
six branches of lumbar plexus in order
iliohypogastric
ilioinguinal
genitofemoral
lateral femoral cutaneous
obturator
femoral
lateral femoral cutaneous
arises from
forms
courses
arises from L2-3 posterior divisions
forms the midpoint of the psoas muscle
courses laterally along the anterior iliac spine, and then passes under the lateral border of the inguinal ligament
the femoral nerve
arises from
forms
courses
arises from posterior divisions of L2-4
forms near the middle and lower 1/3 of psoas muscle
courses distally through groove created by psoas major and iliacus muscles under inguinal ligament lateral to the femoral artery and anterior to the ilipsoas muscle
the femoral nerve divides into
anterior and posterior branches
the posterior branch gives rise to one terminal branch (saphenous nerve)
the saphenous nerve courses through adductor canal and becomes superficial at the knee
the sacral plexus forms anterior to
the psoas major
five major branches of sacral plexus include
superior gluteal
inferior gluteal
posterior cutaneous
pudendal
sciatic
the sciatic nerve arises from
courses through
arises from L4-S3 (comprised of tibial and common fibular trunks)
courses through sacrosciatic foramen (underneath piriformis muscle) and descends between major trochanter and ischial tuberosity
the sciatic nerve divides into 2 branches (which branches and where does it divide)
divides into tibial nerve and common peroneal nerve (fibular nerve) at proximal popliteal fossa
the tibial nerve
arises from
course through
sacral nerve (anterior branch of L4-S3)
courses medially through popliteal fossa distally and between medial and lateral heads of gastrocnemius muscle
the tibial nerve gives rise to what
1 terminal branch (posterior tibial nerve)
the common peroneal nerve
arises from
courses through
sacral nerve (posterior branches of L4-S3)
courses laterally over head of the fibula before dividing into deep and superficial peroneal nerves
the common peroneal nerve gives rise to what branches
3 terminal branches:
deep peroneal nerve
superficial peroneal nerve
sural nerve
what are the 5 terminal nerves at the ankle
saphenous (only one from femoral)
superficial peroneal
deep peroneal
sural
posterior tibial
innervation of A, B, C, D in this image
A: LFCN
B: obturator
C: saphenous
D: superficial peroneal
dermatome L2
sensory region
medial upper thigh
dermatome L3
sensory region
medial lower thigh
dermatome L4
sensory region
lateral thigh and anterior knee
dermatome L5
sensory region
lateral lower leg and top of foot
dermatome S1
sensory region
posterior leg (more lateral)
dermatome S2
sensory region
posterior leg (more medial)
peripheral nerves of LE that are only sensory
LFCN
saphenous
sural
peripheral nerves of LE that are combined motor and sensory
femoral
obturator
posterior tibial
deep peroneal
superficial peroneal
sensory region of femoral nerve
anterior branch -> anterior thigh
posterior branch-> saphenous nerve->medial aspect of lower leg
sensory region of obturator nerve
articular branches of hip joint
medial thigh
sensory region of LFCN
lateral thigh to knee
sensory region of pudendal nerve
perineum
anal canal and external sphincter
sensory region of posterior femoral cutaneous nerve
posterior hip to mid calf
sensory region of posterior tibial nerve
plantar surface of foot
sensory region of superficial peroneal nerve
dorsal surface of foot
sensory region of deep peroneal nerve
web space between big toe and second toe
sensory region of sural nerve
lateral aspect of foot
motor function of femoral nerve
hip–> flexion and lateral rotation
knee–>extension and flexion