The 'femoral nerve', the largest branch of the
lumbar plexus, arises from the dorsal divisions of the second, third, and fourth
lumbar nerves. It descends through the fibers of the
Psoas major, emerging from the muscle at the lower part of its lateral border, and passes down between it and the
Iliacus, behind the
iliac fascia; it then runs beneath the
inguinal ligament, into the
thigh, and splits into an anterior and a posterior division. Under the
inguinal ligament, it is separated from the
femoral artery by a portion of the
Psoas major.
In the abdomen
Within the abdomen the femoral nerve gives off small branches to the
Iliacus, and a branch which is distributed upon the upper part of the femoral artery; the latter branch may arise in the thigh.
In the thigh
Anterior division
In the thigh the anterior division of the femoral nerve gives off anterior cutaneous and muscular branches.
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Anterior cutaneous branches: The anterior cutaneous branches comprise the following nerves: ''intermediate cutaneous nerve'' and ''medial cutaneous nerve''.
★ Muscular branches (rami musculares): The nerve to the
Pectineus arises immediately below the inguinal ligament, and passes behind the femoral sheath to enter the anterior surface of the muscle; it is often duplicated. The nerve to the
Sartorius arises in common with the intermediate cutaneous.
Posterior division
The posterior division of the femoral nerve gives off the saphenous nerve, and muscular and articular branches.
★ The
saphenous nerve (n. saphenus; long or internal saphenous nerve) is the largest cutaneous branch of the femoral nerve.
★ The ''muscular branches'' supply the four parts of the
Quadriceps femoris.
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★ The branch to the
Rectus femoris enters the upper part of the deep surface of the muscle, and supplies a filament to the hip-joint.
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★ The branch to the
Vastus lateralis, of large size, accompanies the descending branch of the
lateral femoral circumflex artery to the lower part of the muscle. It gives off an articular filament to the knee-joint.
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★ The branch to the
Vastus medialis descends lateral to the femoral vessels in company with the
saphenous nerve. It enters the muscle about its middle, and gives off a filament, which can usually be traced downward, on the surface of the muscle, to the knee-joint.
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★ The branches to the
Vastus intermedius, two or three in number, enter the anterior surface of the muscle about the middle of the thigh; a filament from one of these descends through the muscle to the
Articularis genu and the
knee-joint. The articular branch to the
hip-joint is derived from the nerve to the
Rectus femoris.
★ The ''articular branches'' to the knee-joint are three in number.
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★ One, a long slender filament, is derived from the nerve to the
Vastus lateralis; it penetrates the capsule of the joint on its anterior aspect.
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★ Another, derived from the nerve to the
Vastus medialis, can usually be traced downward on the surface of this muscle to near the joint; it then penetrates the muscular fibers, and accompanies the articular branch of the
highest genicular artery, pierces the medial side of the articular capsule, and supplies the
synovial membrane.
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★ The third branch is derived from the nerve to the
Vastus intermedius.
Additional images
External links
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★ - "Femoral nerve dysfunction" (includes illustration)
★ - "Posterior Abdominal Wall: Nerves of the Lumbar Plexus"
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Diagram at nysora.com