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Flashcards in Nerves of the Thigh Deck (48):

Genitofemoral nerve level

Originates from the femoral nerve (L1, L2)


Genitofemoral nerve course

- Located lateral to genital branch
- Passes deep to inguinal ligament
- Runs with external iliac/femoral artery
- Runs in lateral compartment of femoral sheath
- Supplies skin on the proximal, anterior surface
- Lays on top of Psoas major


Lateral femoral cutaneous nerve levels

L2, L3


First appearance of lateral femoral cutaneous nerve

On the middle, lateral border of psoas major


Course of lateral femoral cutaneous nerve

- Passes over iliacus toward anterior superior iliac spine
- Passes under inguinal ligament
- Passes over sartorius muscle


Division of lateral femoral cutaneous nerve

- Anterior branch supplies skin over lateral and anterior thigh
- Posterior branch supplies skin of lateral thigh (greater trochanter to mid-thigh)


Obturator nerve levels

L2, 3, 4


Obturator nerve

- Emerges into medial compartment of thigh
- Then divides into two branches


Two branches of obturator nerve

- Anterior (superficial) branch
- Posterior (deep) branch


Anterior (superficial) branch of obturator nerve

• Located anterior to adductor brevis muscle
• Communicates with accessory obturator (when present)
• Passes over obturator externus muscle, which means it is located deep to pectineus and adductor longus muscles and superficial to adductor brevis muscle
• Gives off articular, muscular and cutaneous branches


Articular branch of anterior obturator nerve

Gives off articular branch to hip joint


Muscular branches of anterior obturator nerve

o Adductor longus
o Gracilis
o Adductor brevis (sometimes)
o Pectineus – motor (rarely)


Cutaneous branches of anterior obturator nerve

Cutaneous branches (when present) innervates skin on medial thigh, just above knee


Posterior (deep) branch of obturator nerve

- Runs posterior to adductor brevis muscle
- Runs anterior to adductor magnus
- Gives off articular branches and muscular branches


Articular branch of posterior obturator nerve

Articular branch to knee joint


Muscular branches of deep obturator nerve

- Obturator externus (as the deep obturator nerve goes through it)
- Adductor magnus
- Adductor brevis (sometimes)


Accessory obturator nerve levels

L3, L4


General information of accessory obturator nerve

- Present in 10% of cases
- Passes deep to pectineus muscle and sends a muscular branch to this muscle
- Potentially gives off an articular branch to the hip joint (potentially)


Femoral nerve level

L2, L3, L4


Course of femoral nerve

- Passes under inguinal ligament (lateral to femoral artery)
- Lies OUTSIDE femoral sheath
- Immediate after the femoral nerve enters the thigh it divides into its branches


Branches of femoral nerve

- Cutaneous branches
- Muscular branches


Cutaneous branch of femoral nerve

Anterior femoral cutaneous branch
- Medial femoral cutaneous branch goes to skin of medial thigh and distally into the leg
- Intermediate femoral cutaneous branch goes to skin of anterior thigh


Muscular branches of femoral nerve

ALL muscles of anterior compartment
- Sartorius
- Quadratus femoris (rectus femoris, vastus medialis, vastus lateralis, vastus intermedius)
- Articularis genu

Also, sometimes the pectineus


Saphenous nerve

- Longest branch of femoral nerve
- Enters adductor canal (with the femoral artery)


Course of saphenous nerve

- Enters adductor canal with femoral artery
- Crosses lateral to medial in canal over artery
- Leaves canal passes to medial side of knee (does NOT pass through adductor hiatus)


Is the saphenous nerve a superficial or deep nerve?

- Passes between tendons of sartorius and gracilis muscles
- Runs with great saphenous vein on teh medial side of the leg


Division and branches of saphenous nerve in proximal leg

In the proximal 1/3 of the leg, the saphenous nerve divides
- Branches into the subsartorial nerve plexus contribution
- Infrapatellar branch (cutaneous innervation to skin over patella)


Division and branches of saphenous nerve in distal leg

In the distal 1/3 of the leg, the saphenous nerve divides into its terminal branches
- Skin supply to anterior and medial side of leg
- Ends at the ankle
- On the medial side of the foot, the saphenous nerve runs as far as the ball of the foot


Subsartorial nerve plexus

- Located at the inferior margin of adductor longus muscle and deep to the sartorius muscle


What is the subsartorial plexus comprised of?

Formed by communications
- Anterior branch of obturator
- Saphenous
- Medial femoral cutaneous nerves


Sciatic nerve

- Largest branch of sacral plexus
- Largest nerve in the body
- Nerve levels: L4-S3


Anterior division of the sciatic nerve

Anterior division is L4-S3


Posterior division of the sciatic nerve

Posterior division is L4-S2


What does the sciatic nerve supply

- Posterior compartment muscles of the thigh
- ALL muscles of the leg and foot
- Skin of foot
- Skin of most of the leg
- ALL joints of the lower extremity


How many nerves is the sciatic nerve anatomically?



How many nerves is the sciatic nerve physiologically?



Describe how the sciatic nerve is physiologically two nerves

- Two nerves wrapped together in a single connective tissue sheath
- NOTE: both nerves separate origins from sacral plexus
- Fibers DO NOT MIX while traveling together
- As the nerve passes into the distal 1/3 of the posterior thigh (as it emerges from beneath the long head of the biceps femoris)


Tibial nerve

Anterior division
- L4-S3


Common peroneal (fibular) nerve

Posterior division
- L4-S2
- It is two words (common peroneal) and it stops at S2


Branches that come off the sciatic nerve before the nerve splits

- Articular branches to hip joint
- Muscular branches to hamstrings


Describe the muscular branches to the hamstrings

- Tibial portion: all posterior compartment muscles of thigh
- One exception: short head of biceps femoris
- Common peroneal portion: short head of biceps femoris


Hint to remember sciatic nerve

Hint: at the Lower end of the sciatic nerve, it gives off 4 branchs (L4, tibial nerve, common peroneal nerve, articular branches to hip joint, muscular branches to hamstrings), the tibial nerve Splits into 3 terminal branches (S3, medial & lateral plantar, and medial calcaneal), and the common peroneal nerve splits into 2 terminal branches (S2, superificial peroneal nerve & deep peroneal nerve).


Variations in the sacral plexus and branches

- Tibial and common fibular nerves may be separate entities from sacral plexus or may travel separate proximal to their usual site of division
- If the tibial nerve and common peroneal nerve separate before leaving plexus, the tibial leaves the pelvis INFERIOR to the piriformis and the common peroneal leaves the pelvis by PIERCING the piriformis


Posterior cutaneous nerve of the thigh variation

May also arise in two parts
- Ventral part (accompanies tibial nerve)
- Dorsal branch (passes through piriformis)


What does the ventral part of the posterior cutaneous nerve of the thigh give rise to?

- Fibular (peroneal) nerve
- Medial cutaneous nerve


What does the dorsal branch of the posterior cutaneous nerve of the thigh give rise to?

- Passes through the piriformis
- Runs with common fibular nerve
- Provides a gluteal branch
- Provides a femoral branch


Variation in inferior pudendal branch

May pierce sacrotuberous ligament


Variation in perforating cutaneous nerve of the thigh

- Missing in 1/3 to 1/2 of bodies
- May arise in common with pudendal nerve