Lumbar neuro Flashcards
What makes up the lumbar plexus?
Ventral rami of spinal nerve roots T12, L1, L2, L3, & L4,
What nerves does the lumbar plexus give rise to?
femoral nerve
obturator
what muscle is the lumbar plexus associated with?
the psaos major as forms in the muscle belly
what spinal nerve roots does the obturator nerve come from?
L2, L3 & L4 ventral (anterior) branches
what are the main peripheral nerves of the lumbosacral plexus?
Sup and Inf gluteal nerve
Sciatic nerve
Tibial- medial and lateral plantar
Common Peroneal- superficial and deep
what spinal nerve roots does the femoral nerve come from?
L2, L3 & L4 dorsal (posterior) branches
what nerve roots does the superior gluteal nerve arise from?
Posterior divisons L4, L5 & S1
what nerve roots does the inferior gluteal nerve arise from?
Posteiror divisions L5, S1 & S2
what nerve roots does the sciatic nerve arise from?
Ventral rami L4-S3
what nerve roots does the tibial nerve arise form?
anetrior divisons of ventral rami of L4, L4, S1, S2 & S3
what nerve roots do the peroneal nerves (deep, superficial and common) arise form?
Posterior divisions of L4, L5, S1, & S2
what are the myotomes of the lower body?
L1 & L2 = hip flexion
L3 = knee extension
L4 = ankle DF
L5 = big toe extension
S1 = ankle eversion
S2 = ankle PF
S3 & S4 = pelvic floor muscles
what are the dermatomes of the lower body?
L = hip flexors
L2 = proximal thigh
L3 = distal thigh (just above knee)
L4 = medial tibia + big toe
L5 = laetral tibia + phalanges
S1 = posterior heel and lower calf
S2 = proximal calf and thigh
What is the differnece between a Spinal Nerve and Peripheral Nerve in terms of location?
Peripheral nerves extend outside the CNS (brain and spinal cord) and travels to various parts of the body (muscles and skin).
Spinal nerves emerge from the spinal cord through openings between the vertebra (vertebral foramina).
What is the function of a Peripheral Nerve?
Peripheral nerves carry sensory information to the brain from the body (e.g. temperature, pain, touch) and motor information from the brain to the muscles or glands, which initiates movements or other responses.
describe the structure of a Peripheral nerve
peripheral nerves consists of bundles of nerve fibres (axons) enclosed in connective tissue sheaths (they may contain both sensory and motor fibres).
What is the function of a Spinal Nerve?
Connect specific regions of the body to the spinal cord
They carry both sensory information from the body to the spinal cord (through dorsal roots) and motor commands from the spinal cord to muscles and glands (through ventral roots)
what type of roots carries the sensory information from the body to the spinal cord?
dorsal root - of a spinal nerve
what do ventral roots do in spinal nerves?
carries motor information from the spinal cord to the body
describe the structure of a spinal nerve
formed by the fusion of dorsal and ventral nerve roots
dorsal = posterior, contain sensory/afferent fibres
ventral = anterior, contain motor/ efferent fibres
what is the spinal cord disease associated with the lumbar spine?
Cauda Equina Syndrome
what is cauda equina?
a rare & severe type of spinal stenosis where all the nerves in the lower back suddenly become compressed
describe the course/ formation of the tibial nerve
- originates from the LS plexus
- nerve roots L4-S3
- emerges from the apex of the popliteal fossa
- decends to the tibialis posterior, passing the deep soleal arch
- it lies between the FHL and FDL
- it then enters the sole of the foot where it divides into medial and lateral plantar nerves
what is the cutaneous supply of the tibial nerve?
gives rise to the sural nerve
- passes dowm the posterior lef to the laetral foot
- cutaneous to medial heel
describe the course/ formation of the medial plantar nerve
- originates from LS plexus
- ventral rami of nerve roots L4-S3
- passes deep to the abductor hallucis to the base of the metatarsals
- motor supply = medial intrinsic foot muscles
- sensory supply = skin on sole of medial 3 1/2 toes
describe the course/ formation of the lateral plantar nerve
- originates from the LS Plexus
- ventral rami of nerve roots L4-S3
- runs alomg the plantar surface of the foot
- motor supply = lateral intrinsic foot muslces
- snesory supply = skin on sole of lateral 1 1/2 toes
describe the course/ formation of the common peroneal nerve
- originates form the LS Plexus
- posterior divisions of L4-S2
- runs from head of fibula
- motor supply = short head of nuceps femoris
- sesnory supply = lateral calf
describe the course/ formation of the superficial nerve
- originates from the LS Plexus
- posterior divisons of L4-S2
- runs along the lateral lower leg
- motor supply = peroneus longus and braves
- sensory supply = dorsal foot
describe the course/ formation of the deep peroneal nerve
- originates from the LS Plexus
- posterior divisons of L4-S2
- runs along the anterior lower leg
- motor supply = tibialis anteiror, EHL, EDL
describe the corse/formation of the sciatic nerve
-originates from the LS Plexus
-ventral rami of L4-S3
-lies anterior to the piriformis within the pelvis
-leaves the greater sciatic notch and travels to the adductor magnus, anterior to the biceps femoris
-once it passes past the lower 2/3rds of the femur, it divides into the tibial and common peroneal nerves
