Flashcards in USMLE Road Map - Lower Limb III Deck (29):
The common fibular nerve emerges from the ...?
Pelvis with the tibial nerve inferior to the piriformis muscle. It courses with the tibial nerve into the posterior thigh.
The common fibular nerve innervates the ...?
The short head of the biceps femoris muscle in the posterior thigh --> Then separates from the tibial nerve at the superior border of the popliteal fossa.
The common fibular nerve courses ...?
Laterally along the tendon of the biceps femoris muscle and spirals around the neck of the fibula into the lateral compartment of the leg.
The common fibular nerve enters the ... muscle and divides into the ...?
Fibularis longus muscle and divides into the superficial fibular and deep fibular nerves.
The most frequently lesioned nerve in the lower limb?
The common fibular nerve.
In piriformis syndrome, the common fibular nerve may be compressed ...?
By the fibers of the piriformis muscle when the nerve passes through the piriformis rather than anterior to it with the tibial nerve.
The superficial fibular nerve - Fibers from ...?
The supeficial fibular nerve innervates the ...?
Fibularis longus and brevis muscles in the lateral compartment of the leg.
The superficial fibular nerve emerges in the ...?
Distal third of the lateral leg.
The superficial fibular nerve innervates ...?
Skin of the lateral leg and dorsum of the foot except for the first dorsal webbed space between the great toe and second toe.
The superficial fibular nerve may be lesioned as the nerve emerges from the ...?
Lateral compartment of the leg.
--> Patients experience pain and paresthesia in the dorsal aspect of the foot.
The deep fibular nerve - Fibers from ...?
The deep fibular nerve courses through the ... muscle and the ... compartment of the leg with the anterior ... artery.
Fibularis longus muscle and the anterior compartment of the leg with the anterior tibial artery.
The deep fibular nerve innervates muscles in the ...?
Anterior compartment of the leg, including the:
1. Tibialis anterior.
2. Extensor hallucis longus.
3. Extensor digitorum longus.
4. Peroneus tertius.
+ Muscles in the dorsum of the foot:
1. Extensor digitorum brevis.
2. Extensor hallucis brevis.
The deep fibular nerve also innervates the skin ...?
Of the webbed space between the great toe and the second toe.
The deep fibular nerve may be compressed in the ...?
Anterior compartment of the leg.
--> Patients may have footdrop and paresthesia in skin of the webbed space between the great toe and the 2nd toe.
Collateral nerves of the lumbosacral plexus:
1. Sural nerve.
2. Nerve to the quadratus femoris muscle (L4-S1).
3. Nerve to the obturator internus muscle (L5-S2).
4. Posterior femoral cutaneous nerve (anterior + posterior division fibers from S1-S3).
5. Nerve to the piriformis muscle (S1-S2).
6. Perforating cutaneous nerve (S2-S3).
The sural nerve innervates ...?
The skin of the posterior leg and lateral aspect of the foot.
The sural nerve receives contributions from the ... and ... nerves.
Tibial and common fibular nerves.
The sural nerve courses with the ...?
Small saphenous vein in the posterior leg.
The nerve to the quadratus femoris muscle (L4-S1) enters the gluteal region after passing through ...?
The greater sciatic foramen.
The nerve to the quadratus femoris (L4-S1) innervates the ...?
1. Quadratus femoris.
2. Inferior gemellus.
The nerve to the obturator internus muscle (L5-S2) enters the gluteal region after ...?
Passing through the greater sciatic foramen.
The nerve to the obturator internus (L5-S2) innervates:
1. Superior gemellus.
2. Obturator internus.
The posterior femoral cutaneous nerve (S1-S3) innervates ...?
The skin of the posterior thigh and upper calf.
The posterior femoral cutaneous nerve is the only branch of the lumbosacral plexus that ...?
Contains BOTH anterior division (S2-S3) and posterior division (S1-S2) fibers.
The nerve to the piriformis muscle (S1-S2) arises from the ...?
1st and 2nd sacral ventral rami.
--> Innervates piriformis.
The perforating cutaneous nerve (S2-S3) arises from the ...?
2nd and 3rd sacral ventral rami.
--> Innervates skin covering the ischioanal fossa and the gluteal region near the anal canal.