Lumbosacral Plexus Diagram – Label the Nerves

All 17 parts on the diagram

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Lumbar plexus 11

Femoral nerve The largest nerve of the lumbar plexus, from L2, L3 and L4. It runs down to the front of the thigh.
Obturator nerve From L2, L3 and L4, to the inner thigh.
Lumbosacral trunk Part of L4 joins L5 to make this trunk. It runs down into the pelvis to join the sacral plexus.
Lateral femoral cutaneous nerve From L2 and L3, to the skin of the outer thigh. It is a sensory nerve only.
Genitofemoral nerve From L1 and L2. It soon splits into genital and femoral branches.
Ilioinguinal nerve From L1, just below the iliohypogastric nerve. It follows the same course and is the smaller of the two.
Iliohypogastric nerve The first branch of the plexus, from L1. It often carries fibers from T12 as well.
L1 root Gives the iliohypogastric and ilioinguinal nerves and part of the genitofemoral.
L2 root Feeds four nerves: genitofemoral, lateral femoral cutaneous, femoral and obturator.
L3 root Feeds the lateral femoral cutaneous, femoral and obturator nerves.
L4 root Feeds the femoral and obturator nerves and the lumbosacral trunk.

Down the limb 6

Sciatic nerve The body's largest nerve, from roots L4 to S3. It runs down the back of the thigh.
Tibial nerve One of the two end branches of the sciatic nerve. It runs down the back of the leg to the sole of the foot.
Common fibular nerve (common peroneal nerve) The other end branch of the sciatic nerve. It winds round the fibula's neck and divides in two.
Superficial fibular nerve (superficial peroneal nerve) One of the two end branches of the common fibular. It supplies the muscles on the outer side of the leg.
Deep fibular nerve (deep peroneal nerve) The other end branch of the common fibular nerve. It supplies the muscles at the front of the leg.
Saphenous nerve The long skin branch of the femoral nerve. It runs down the inner side of the leg to the foot.

How this list was compiled: Every name and root level checked on 2026-10-03 in two of these. (1) TeachMeAnatomy, The Lumbar Plexus, https://teachmeanatomy.info/lower-limb/nerves/lumbar-plexus/, with its pages on the femoral, sciatic and common fibular nerves. (2) Wikipedia, English edition, Lumbar plexus (its table of nerves and segments), Lumbosacral trunk, Femoral nerve, Obturator nerve, Saphenous nerve, Sciatic nerve and Common fibular nerve, text only. (3) Henry Gray, Anatomy of the Human Body, 1918 (public domain), The Lumbosacral Plexus, https://www.bartleby.com/lit-hub/anatomy-of-the-human-body/6d-the-lumbosacral-plexus. Hints and detail lines are in our own words. Licence: own work

The drawing: Drawn for this site on 2026-10-05 by script. The outlines of the hip bone and sacrum are plotted after fig. 241, the femur after fig. 244 and the tibia and fibula after fig. 258 of Henry Gray, Anatomy of the Human Body, 20th edition, 1918 (public domain; https://commons.wikimedia.org/wiki/File:Gray241.png, https://commons.wikimedia.org/wiki/File:Gray244.png, https://commons.wikimedia.org/wiki/File:Gray258.png); the courses of the nerves follow figs. 823, 824, 827 and 832 of the same book. A plan laid over the bones; the long bones are shortened. Licence: own work

How it works

The first drawing is a plan of the left lumbar plexus seen from the front, each nerve drawn from the roots that feed it. The second follows the long nerves down the limb to the foot.

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Follow each nerve back to its roots

Numbers 8 to 11 are the roots L1 to L4. The femoral nerve (1) and the obturator nerve (2) both gather from L2, L3 and L4. Part of L4 runs down with L5 as the lumbosacral trunk (3). The lateral femoral cutaneous nerve (4) comes from L2 and L3, the genitofemoral nerve (5) from L1 and L2, and the ilioinguinal (6) and iliohypogastric (7) nerves from L1.

Then down the limb

The sciatic nerve (12) splits above the knee into the tibial (13) and common fibular (14) nerves. The common fibular nerve splits again into the superficial (15) and deep (16) fibular nerves. The saphenous nerve (17) is the long branch of the femoral nerve.

The two nerves from L1 run side by side: the iliohypogastric is the upper one.
Femoral and obturator share the same three roots; the femoral is the thicker and runs out to the side.

Questions and answers

What are the roots of the lumbar plexus?

The anterior rami of L1 to L4, often with a small branch from T12. Part of L4 joins L5 as the lumbosacral trunk, which links the lumbar plexus to the sacral plexus below it.

Which nerves arise from the lumbar plexus?

Six major nerves: the iliohypogastric, ilioinguinal, genitofemoral, lateral femoral cutaneous, obturator and femoral nerves. The largest is the femoral nerve.

Which nerves come from L2, L3 and L4?

The femoral nerve and the obturator nerve. The femoral nerve runs to the front of the thigh and the obturator nerve to the inner thigh.

Where does the sciatic nerve divide?

Usually at the top of the hollow behind the knee, where it separates into the tibial nerve and the common fibular nerve, which then winds round the fibula's neck and divides again.

Can I practice here for “label the nerves of the lumbosacral plexus”?

Yes, for practice. That sentence is the instruction of a labeling exercise. The drawings here are our own and not a copy of any course figure, so your figure may show other nerves.