Femoral nerve

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Nerve: Femoral nerve
Gray823.png
The lumbar plexus and its branches. (Femoral labeled at bottom left.)
Gray545.png
Femoral sheath laid open to show its three compartments. (Femoral nerve visible in yellow.)
Latin nervus femoralis
Gray's p.955
Innervates anterior compartment of thigh
From L2
To L4
MeSH Femoral+nerve

The femoral nerve, the largest branch of the lumbar plexus, arises from the dorsal divisions of the ventral rami of the second, third, and fourth lumbar nerves (L2-L4). It descends through the fibers of the psoas major muscle, emerging from the muscle at the lower part of its lateral border, and passes down between it and the iliacus muscle, 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.

Structure[edit]

Within the abdomen the femoral nerve gives off small branches to the iliacus muscle, and a branch which is distributed upon the upper part of the femoral artery (a continuation of the external iliac artery); the latter branch may arise in the thigh.

Anterior division[edit]

In the thigh the anterior division of the femoral nerve gives off anterior cutaneous and muscular branches.

  • Anterior cutaneous branches: The anterior cutaneous branches comprise the following nerves: intermediate femoral cutaneous nerve and medial femoral cutaneous nerve (Note the lateral femoral cutaneous nerve is a branch from the lumbar plexus.)
  • 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[edit]

The posterior division- muscular branches supply the four parts of the Quadriceps femoris.

    • 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.
    • 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.
    • 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.
    • 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.
    • 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.
    • 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.
    • The third branch is derived from the nerve to the Vastus intermedius.

Function[edit]

Femoral nerve functions to extend the knee, and is responsible for sensation over the anterior and medial aspects of the thigh, medial shin, and arch of the foot.

Additional images[edit]

References[edit]

This article incorporates text from a public domain edition of Gray's Anatomy.

External links[edit]