the lumbosacral plexus Flashcards
what rami of spinal nerves forms the lumbosacral plexus?
the anterior rami of spinal nerves
L1-S4
What spinal levels compose the lumbar plexus?
L1-L4
What spinal levels compose the Sacral plexus?
L5-S4
which plexus is responsible for the cutaneous innervation of the anterior and medial thigh, anterior knee and medial leg and foot?
lumbar plexus
which plexus is responsible for the cutaneous innervation to the lower buttocks, posterior thigh, lateral and posterior leg and the majority of the foot?
sacral plexus
which plexus is responsible for the motor innervation to the gluteal region, posterior thigh, compartments of the leg and foot?
sacral plexus
which plexus is responsible for the motor innervation to anterior and medial compartments of the thigh
lumbar plexus
what spinal levels compose the lumbosacral trunk?
L4-L5
What is nerve formed by the junction of the L4-L5 junction?
lumbosacral trunk
what nerve(s) are responsible for the motor innervation to the lower internal obliques and transversis abdominis muscles?
iliohypogastric nerve
ilioinguinal nerve
what is the cutaneous innervation of the iliohypogastric nerve?
lateral gluteal region
what si the cutaneous innervation of the ilioinguinal Nerve?
upper medial thigh and scrotal/labial branches
what nerve pierces through the obliques and travels superior to the inguinal ligament?
iliohypogastic N.
what nerve of the lumbar plexus is associated with T12-L1 spinal levels?
iliohypogastic N.
where is the ilioinguinal nerve located?
it peak between quadratus lumbarus and psoas major, passes along the iliac crest into the abdominal wall and through the inguinal canal
what is the fascial canal acting as a conduit between the internal and external pelvis?
inguinal canal
what nerve of the lumbar plexusis associated with L1 spinal level?
ilioinguinal N.
what nerve of the lumbar plexus pierces through the psoas major muscle?
genitofemoral
which branch of the genitofemoral N. innervates both sensory and motor?
genital branch
what region does the femoral branch of the genitofemoral N. innervate
lateral-central innervation of the superior thigh
what muscle gets innervated by the genital branch of the genitofemoral N?
cremaster muscle
what gets tested during the cremaster reflex?
by touching the region of skin innervated by the genital branch it may stimulate motor innervation and we will see the testes move
what region is cutaneously innervated by the gential branch?
medial thigh, shares the same innervation as ilioinguinal N.
what is the nerve responsible for the cutanoeus innervation of the lateral thigh?
lateral femoral cutaneous N.
what spinal levels are associated with the Lateral femoral cutanoeus N?
L2-L3
what nerve of the lumbar plexus is associated with L1-L2 spinal levels?
genitofemoral N.
what nerve is responsible for the motor innervation of the medial compartments of the thigh (Adductors) and obturator externus?
obturator N.
what spinal levels are associated to obturator N,
L2-L4
what region of the thigh is cutanoeusly innervated by obturator N.?
medial thigh
what nerve splits into branches after passing through the inguinal ligament?
femoral N.
what spinal levels correspond to the femoral nerve?
L2-L4 (like obturator)
what is the motor innervation of the femoral nerve?
anterior compartment of the thigh (hip flexors, knee extensors)
what are the 2 cutaneous branches that originate from the femoral N.?
anterior femoral cutanoeus N.
saphenous N.
what does the saphenous N. innervate?
sensory innervation of the medial leg and foot
where does the saphenous N. travel, and along what?
it travels down the medial leg along with the greater saphenous vein.
what nerves make up the lumbar plexus?
iliohypogastic N. ilioinguinal N. Genitofemoral N. Lateral femoral cutanoeus N. Obturator N. femoral N. Lumbosacral trunk
what does the superior gluteal nerve innervate?
gluteus medius and minimum, tensor fascia lata
what muscle is an important landmark for inferior/superior gluteal N.
piriformis
what spinal levels are asssociated with the superior gluteal N.?
L4-S1
what spinal levels are asssociated with tinferiorgluteal N.?
L5-S2
what muscle is innervated by the inferior gluteal N?
gluteus maximus
are the superior and missle cluneal N. part of the lumbosacral plexus? why?
no, because they are from the posterior rami of spinal nerves, where as the lumbosacral plexus is composed of the anterior rami of spinal nerves
inferior cluneal N. is a branch of which nerve?
posterior femoral Cutaneous
what nerves sits medially to sciatic nerve?
posterior femoral cutaneous n.
what spinal level corresponds to the sciatic N?
L4-S3
what nerve corresponds to the following spinal level S1-S3
posterior femoral cutaneous N.
what region is innervated by the posterior femoral cutaneous n?
the posterior thigh
what nerve has a tortuous course but goes through genitalia and controls anal sphincters?
pudenal N.
what spinal levels correspond to the pudendal n?
S2-S4
what does the sciatic nerve innervate?
posterior compartment of the thigh and its branches will innervate leg and foot
what are the 2 branches that originate from the sciatic N?
tibial N
Common fibular N.
what branch of the sciatic N. runs along the lateral side of the leg?
common fibular n.
what branch of the sciatic N. runs along the back of the leg?
tibial N.
what cutaneous branch originates from the tibial N.
medial Sural Cutaneous N
what spinal levels correspond to the tibial N.
L5-S3
what spinal levels correspond to the common fibular N?
L4-S2
what cutaneous branch originates from the common fibular N.
Lateral Sural cutaneous N.
how id the sural N. formed?
the medial and lateral Sural cutaneous branches merge together in the leg
what does the sural nerve innervate
sensory innervation of the posterior and lateral leg and lateral foot
what does the MSC N. innervate?
sensory innervation of the middle compartment of the upper posterior leg
what does the LSC N. innervate?
Lateral knee and lateral side of the upper leg
