LEA - Neurology Flashcards
name the branches of the lumbar plexus and what ventral rami compose them
name the branches of the sacral plexus and what ventral rami compose them
what nerves make up the sciatic nerve?
tibial n & common peroneal n.
name the dermatomes of the anterior aspect of the lower extremity
name the dermatomes of the posterior aspect of the lower extremity
name the dermatomes of the dorsal foot
medial to lateral:
L4, L5, S1
name the dermatomes of the plantar foot
medial to lateral:
L4, L5, S1
Remember, these tend to vary by reference but the nerve roots are consistent
what cutaneous nerve is responsible for the L4 dermatome?
saphenous n.
(posterior division of femoral n.)
what are the cluneal nerves?
cutaneous nerves supplying the gluteal region
- Superior cluneal n. (L1-3 dorsal rami)*
- Middle cluneal n. (S1-3 dorsal rami)*
- Inferior cluneal n. (S1-3 ventral rami)*
what nerve roots are responsible for the knee jerk reflex?
L2 through 4
(kick the door)
what nerve roots are responsible for the Achilles reflex?
S1, S2
(tie your shoe)
*primarily S1
what is a positive Babinski sign in an adult suggestive of?
upper motor neuron (UMN) lesion
what action and muscle can test the integrity of the L4 spinal nerve?
dorsiflexion and inversion of the foot,
which tests the tibialis anterior m.
what action and muscle can test the integrity of the L5 spinal nerve?
dorsiflexion of the hallux,
which tests the Extensor hallucis longus m.
what action and muscles can test the integrity of the S1 spinal nerve?
eversion of the foot,
which tests the peroneus longus and peroneus brevis m.
all muscles of the plantar foot are innervated by branches of the lateral plantar nerve save for what muscles?
trick: “LAFF”
* innervated by the medial plantar n.:*
- 1st Lumbrical
- ABductor hallucis (AbH)
- Flexor hallucis brevis (FHB)
- Flexor digitorum brevis (FDB)
*FDB may be innervated by BOTH the medial and lateral plantar n.
a patient leans to his left side with each step forward.
what is this gait called and what side is affected?
trendelenburg (or gluteus medius) gait,
due to a lesion of the left superior gluteal n.
- *lesion of superior gluteal n. –> weakness of gluteus medius & minimus muscles –> leads to hip drop on the opposite side –>*
- to compensate, the person will tilt toward the affected side*
a patient presents with a gait that requires him/her to shift the trunk backward with each step forward on the affected side.
what is this gait called and what nerve is affected?
Lurch (or gluteus maximus) gait
due to a lesion of the inferior gluteal n.
a patient presents with a foot drop (or the inability to dorsiflex their foot at the ankle).
he/she can still evert their foot.
what nerve is potentially compromised?
deep peroneal n.
describe the cutaneous innervation to each interspace on the dorsum of the foot
- 1st interspace - deep peroneal n.
- 2nd interspace - medial dorsal cutaneous n.
- 3rd interspace - intermediate dorsal cutaneous n.
- 4th interspace - intermediate dorsal cutaneous n.
describe the autonomic innervation to the lower extremity
there is only sympathetic innervation
(no parasympathetic) to the lower extremity
Spinal roots T10-L3 are responsible for these contributions. The sympathetic nerves travel with blood vessels. They work to vasodilate and vasoconstrict blood vessels, stimulate sweat glands, and contract erector pili muscles.
