(BQ) Part 2 book “Atlas of anatomy of the peripheral nerves” has contents: The obturator nerve, the femoral nerve, the sciatic nerve, the tibial nerve, the common fibular nerve, the lateral femoral cutaneous nerve, other nerves. | Part III NERVES OF THE LOWER LIMB THE LUMBOSACRAL PLEXUS 176 NERVES OF THE LOWER LIMB © 2016 Rigoard. All rights reserved nerves of the lower limb 177 The Lumbosacral Plexus Morphological Data The innervation of lower limbs is controlled by the lumbosacral plexus. The Lumbar Plexus The lumbar plexus is made up of the union of the anterior branches of the four first lumbar spinal nerves. This connection occurs between the corporeal insertion (in front) and the costotransverse head of the psoas muscle (behind), at the level of the transverse apophyses of the lumbar vertebrae. In more than half of the cases, a ramification from T12 also participates to the constitution of the lumbar plexus. At its origin, the lumbar plexus is a triangle shape that widens laterally as one looks further away from its origin. It goes through the iliopsoas muscle and then faces the kidney in front and the quadratus lumborum muscle behind. • The obturator nerve (union of the most anterior ventral branches of L2, L3 and L4) • The femoral nerve (union of the most posterior ventral branches of L2, L3 and L4 and whose bulkiest divisions undergo an anastomosis in order to constitute this nerve) • The lateral femoral cutaneous nerve (made up of the thinnest branches of the previously mentioned divisions) UP T11 LAT T12 L1 The ventral ramus of L1 splits into three branches: an upper branch, making the iliohypogastric nerve; an intermediate branch, making the ilioinguinal nerve; and a lower branch, merging with the ventral ramus of L2 to constitute the genitofemoral nerve. L2 L3 The ventral ramus of L2 divides into four branches participating in the formation of the genitofemoral nerve (having an anastomosis with a branch of the ventral ramus of L1), lateral femoral cutaneous nerve (having an anastomosis with a ramus from L3), obturator nerve and femoral nerve. L4 L5 The ventral ramus of L3 divides into three branches: the ramus anastomotic with L2 that forms the
