Assertion: lumbar plexus | /r/CapableOf | unite with ventral rami of the s1
Facets:
value: to s4 nerve roots
type: LOCATION
Source sentences:
text: The sacral plexus forms on the anterior belly of the piriformis muscle and is formed by the lumbosacral trunk (L4-5) of the lumbar plexus, which enters the pelvis coursing medially to psoas major and unites with the ventral rami of the S1 to S4 nerve roots, which emerge from the anterior foramina of the sacrum.