Lumbosacral plexus

Lumbar and sacral plexus anatomy explained.. with autonomic nervous system of GI tract explained

1. Lumbosacral Plexus Suman Acharya

2. Lumbar Plexus Anterior rami of spinal nerve L1 to L4 ( with T12 ) Six major nerves Iliohypogastric nerve Ilioinguinal nerve Genitofemoral nerve Lateral Cutaneous nerve of thigh Obturator nerve Femoral nerve

3. Sacral Plexus Posterior pelvic wall in front of piriformis muscle Anterior/ventral rami of S1 to S4 and lumbosacral trunk (L5 joined by L4) Anteriorly, parietal pelvic fascia separating internal iliac vessels and rectum Posteriorly, piriformis muscle

4. Branches (major) Superior gluteal Inferior gluteal Sciatic nerve Posterior femoral cutaneous nerve Pudendal nerve Pelvic splanchnic nerve

5. Autonomic component Parasympathetic: Vagus nerve provide preganglionic fibers till splenic flexure Pelvic splanchnic nerve (S2-S4) Sympathetic: preganglionic fiber sympathetic trunk splanchnic nerves Synapse with ganglions

6. Superior hypogastric plexus & Inferior hypogastric plexus