The anterior divisions of the lumbar nerve, sacral nerve, and coccygeal nerves form the lumbosacral plexus, the first lumbar nerve being frequently joined by a branch from the twelfth thoracic. For descriptive purposes this plexus is usually divided into three parts:

* Wikipedia reference-linklumbar plexus
* Wikipedia reference-linksacral plexus
* Wikipedia reference-linkpudendal plexus

Really this is what lectures and text books are for.