Nerves of the Lower Limb

What happens to ventral rami?

all except T1-T12 merge to form plexus

What is a plexus?

spinal levels mix

Where is the lumbar plexus located?

T12-L4

Where is the sacral plexus located?

L4-S4

What is T1-T12 considered?

intercostal nerves

Nerve plexuses travel to _______

peripheral (ex. femoral n.) ——> target (muscle)

What plexuses are associated with the lower limb?

lumbar (T12-L4) and sacral (L4-S4) plexuses

What nerve(s) branch off the lumbar plexus?

femoral n. and obturator n.

The ventral rami from what spinal cord levels form the femoral n. ?

L2-L4

The femoral n. runs deep to the _________ to enter the ________.

inguinal ligament; anterior thigh

The femoral n. innervates what muscle(s)?

anterior thigh m., iliacus m., and half of the pectineus m.

The obturator n. enters _______ through the ________.

medial thigh; obturator foramen

The obturator n. innervates what muscle(s)?

all medial thigh m.

What nerves branch off the sacral plexus?

superior gluteal n., inferior gluteal n., sciatic n., common fibular n., tibial n., deep fibular n., and superficial fibular n.

The ventral rami from what spinal cord levels form the superior gluteal n. ?

L4-S1

The superior gluteal n. exits the pelvis through the ___________.

greater sciatic foramen

The superior gluteal n. is superior to what muscle?

piriformis m.

The superior gluteal n. innervates what muscle(s)?

gluteus medius/minimus m. and tensor fasciae latae m.

The ventral rami from what spinal cord levels form the inferior gluteal n. ?

L5-S2

The inferior gluteal n. exits the pelvis through the _________.

greater sciatic foramen

Is the inferior gluteal n. superior or inferior to the piriformis m.

inferior

The inferior gluteal n. innervates what muscle(s)?

only the gluteus maximus m.

The ventral rami from what spinal cord levels form the sciatic n. and tibial n. ?

L4-S3

The sciatic n. bifurcates into what nerve(s)?

tibial and common fibular nn.

The tibial n. has superficial content with ________.

popliteal fossa

The tibial n. innervates what muscle(s)?

posterior thigh m. (expect the biceps femoris short head) and all posterior leg m.

Tibial n. bifurcates into what nerves?

medial and lateral plantar nn.

Where does the division of the tibial nerve into the medial and lateral plantar nn. occur?

deep to the abductor hallucis

The medial plantar n. innervates what muscle(s)?

abductor hallucis m. and flexor digitorum brevis m.

The lateral plantar n. innervates what muscle(s)?

abductor digiti minimi m.

The ventral rami from what spinal cord levels form the common fibular n. ?

L4-S2

The common fibular n. is the ________ division of the sciatic n.

lateral

Common fibular n. wraps around what?

the neck of the fibula

Common fibular n. bifurcates into what nerves?

superficial and deep fibular n.

The common fibular n. innervates what muscle(s)?

biceps femoris: short head

The superficial fibular n. is the _________ division of the common fibular n. ?

lateral

Superficial fibular n. runs between the _____ and ________.

fibularis longus m. ; fibularis brevis m.

The superficial fibular n. innervates what muscle(s)?

both lateral leg m.

The deep fibular n. is the _______ division of the common fibular n.

medial

Deep fibular n. travels between _______ and _________ .

tibialis anterior m. ; extensor hallucis longus m.

What nerve provides sensory to the foot?

superficial fibular n.

What nerve provides sensory in the “flop-flop” area only?

deep fibular n.

The deep fibular n. innervates what muscle(s)?

all anterior leg m. and both m. of the dorsum of the foot

What causes foot drop?

damage to the common fibular n. superficial to the neck of the fibula

If the deep fibular nerve was damaged, what would happen?

a person would not be able to dorsiflex the ankle and extend all digits

If the superficial and deep fibular n. was damaged, what happen?

a person would not be able to evert their foot