Nerves of the lower limb

Question 1

What level is the lumbar plexus at?

Answer 1

Lumbar plexus (L1 -l4)

Question 2

What is the lumbar plexus?

Answer 2

The lumbar plexus is a network of nerve fibres that supplies the skin and musculature of the lower limb.

Question 3

What level is the lower limb supplied by and what does it form?

Answer 3

The lower limb is supplied by eight spinal nerve roots (L1-S3) which contribute to the lumbar and sacral plexuses.

Question 4

What does the lumbar plexus innervate?

Answer 4

The lumbar plexus (L1-L4) branches within the psoas major muscle (big hip flexor muscle located from the lumbar spine) and supplies the anterior and medial compartments of the thigh.

Question 5

What doe the sacral plexus innervate?

Answer 5

The rest of the lower limb is supplied by the sacral plexus (S1-S3) which includes the lumbosacral trunk (L4/5). You may be able to see parts of the sacral plexus anterior to the sacrum in the lower quarter specimen or in a deep pelvic dissection.

Question 6

What is the largest nerve in the body and identify it

Answer 6

Sciatic nerve and on image

Question 7

What does the sciatic nerve supply?

Answer 7

The sciatic nerve supplies the muscles in the posterior compartment of the thigh.

Question 8

What does the sciatic nerve branch into and what do they supply?

Answer 8

The tibial branch of the sciatic nerve supplies the posterior thigh (hamstring muscles). Identify it within the popliteal fossa as it passes into the leg

Question 9

What muscles are the soleus and gastrocnemius (collectively: triceps surae innervated by?

What is there common tendon?

Answer 9

soleus and gastrocnemius (collectively: triceps surae). These muscles are also supplied by the tibial nerve. Their common tendon is the Achilles tendon.

Question 10

Identify the common peroneal (fibular) nerve as it winds round the neck of the fibula

Answer 10

On image

Question 11

Locate the femoral nerve, and what does it supply?

Answer 11

In the proximal thigh, locate the femoral nerve (which supplies quadriceps) and note how early it branches.

Question 12

Identify the obturator nerve in the eviscerated pelvis and what does it supply?

Answer 12

Identify the obturator nerve in the eviscerated pelvis. This nerve supplies the medial (adductor) compartment of the thigh.

On image