part of part of Homo sapiens lumbar vertebra 4 lumbar vertebral arch vertebral arch of fourth lumbar vertebra 2026-03-19T00:00:00Z A neural arch of the fourth lumbar vertebra, consisting of robust pedicles and wide laminae that form the vertebral foramen enclosing the cauda equina at the level where the iliac crests are typically palpated as a clinical landmark. Its broad, horizontal spinous process and lateral transverse processes serve as attachment sites for the iliolumbar ligament. David Osumi-Sutherland