What is the sciatic nerve?

The sciatic nerve is called the sciatic nerve. Gray's Anatomy (1918) describes it as the largest nerve in the body.

What it is

  • The largest nerve in the body.
  • About the width of a thumb at its origin.
  • Supplies most of the muscles and skin of the lower limb.

Where it is

  • Arises from the lower spinal nerves in the pelvis.
  • Passes out through the greater sciatic notch of the hip bone.
  • Runs down the back of the thigh and divides above the knee into the tibial and common peroneal nerves.

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Last verified: 2026-07-18

  • Best Anatomy Answers is an educational reference about human anatomy. It is not medical advice — for any health concern, talk to a licensed medical professional.

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