Lower Limb Innervations

Question 1

Lumbar Plexus

Answer 1

formed from l1-l4; terminal nerve branches: femoral and obturator nerve

Question 2

Sacral Plexus

Answer 2

Formed by L4-S4; terminal nerve branches: gluteal and sciatic nerve

Question 3

List the action evoked by the patellar reflex

Answer 3

-knee jerk, stretch ( simple flex arc), begins w/ tap to structure below patella, ends w/ knee extension

Question 4

Obturator Nerve

Answer 4

Lumbar plexus branch, travels through obturator foramen to the medial thigh, motor innervation ((medial thigh compartment (abductor longus, brevis, magnus, gracilis)), sensory innervation: skin of medial thigh

Question 5

Sciatic nerve and branches

Answer 5

sacral plexus branch, huge nerve, passes through greater sciatic notch, emerges below pririformis, descends posterior thigh comprised of 2 nerves: tibial and common fibular nerve, together innervate: posterior thigh and all leg and foot muscles

Question 6

Tibial nerve

Answer 6

-from medial branch, sacral plexus branch. Travels from the post. Thigh to the medial leg near tibia to the plantar foot surface. Motor innervation: posterior thigh compartment (hamstrings), posterior leg compartment and most foot muscles. Sensory innervation: skin on plantar foot surface

Question 7

Common fibular nerve

Answer 7

lateral branch, sacral plexus branch, begins posterior, travelsaround the head of fibula from posterior to anterior, when anterior the nerve splits into: superficial fibular and deep fibular nerve.

Question 8

Superficial fibular nerve

Answer 8

Travels in the lateral leg compartment near fibula to the dorsum of foot. Motor innervation: (fibularis longus and brevis evert the foot)—> muscles in lateral leg compartment, sensory innervation: skin on the dorsum of foot, expect btwn 1st/ 2nd toes (1st interdigital cleft) —> numbness

Question 9

Deep fibular nerve

Answer 9

Travels in the anterior leg to the dorsum of foot, btwn the 1st two toes. Motor innervation–> foot drop/cannot dorsiflex ankle: (tibilis anterior, extensor hallucis longus, extensor digitorum longus) —> muscles in the anterior compartment of the leg, sensory innervation: skin between the hallux and 2nd ties (1st interdigital cleft)

Question 10

Describe why the common fibular nerve is vulnerable to injury and the somatic impairments that result from common fibular nerve damage

Answer 10

the nerve is superficial. wraps around the fibular neck. very exposed as a result so it is easily damaged