Femoral nerve

Dr Henry Knipe et al.

The femoral nerve is a large nerve arising from the lumbar plexus and one of two major nerves supplying the lower limb.

Origin

It arises from posterior divisions of L2-L4 roots of the lumbar plexus.

Course
Femoral triangle
  • lies above iliacus, outside and lateral to the femoral sheath
  • sends a branch to pectineus
  • the lateral femoral circumflex artery separates the nerve into superficial and deep divisions
  • the terminal branch of the deep division reaches the apex of the femoral triangle to become the saphenous nerve

See the article: femoral triangle

Branches
Superficial division

Branches of the superficial division include:

  • the nerve to sartorius
  • medial cutaneous nerve of thigh contributes to subsartorial plexus (with branches of the obturator and saphenous nerves)
  • the intermediate cutaneous nerve of thigh
  • sympathetic vasomotor supply to blood vessels
Deep division

Branches of the deep division include:

Supply

The femoral nerve provides motor supply to the anterior compartment of the thigh and sensory supply to the hip, anterior and medial thigh, knee, and medial leg (as the saphenous nerve).

  • femoral nerve splits into two or three separate slips within the psoas muscle but unites to descend as a single bundle 2
  • accessory femoral nerve: fibres arise separately in lumbar plexus, passes anterior to femoral nerve, may terminate as saphenous nerve / cutaneous branch
  • femoral branch replacing lateral femoral cutaneous nerve which usually branches directly off lumbar plexus
  • saphenous nerve terminating  at knee with distribution replaced by branch of the tibial nerve

Femoral nerve is endangered by trauma. Injury results in weakness of thigh extension and numbness overlying the anterior/medial thigh and medial leg.

The femoral nerve is responsible for the patellar tendon reflex (tests L3-L4 spinal component)

Lower limb anatomy
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Article information

rID: 24728
Section: Anatomy
Tags: refs, cases
Synonyms or Alternate Spellings:
  • Femoral nerves

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Cases and figures

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    Figure 1: femoral nerve
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    Figure 2: lumbar plexus labelled
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