Fifth Lumbar Vertebra, Lateral View

Description

Positioned at the caudal end of the lumbar lordosis, the fifth lumbar vertebra (L5) is rendered in lateral profile with the L5 to S1 junction and adjacent intervertebral discs in view. The vertebral body sits anterior to the vertebral arch, while the laminae converge posteriorly toward the spinous process; the transverse process projects laterally from the pedicle region. Superior and inferior articular processes are emphasized by their facet orientation, with the inferior facets facing more anteriorly to meet the superior articular facets of the sacrum at the lumbosacral (L5 to S1) articulations. Facet orientation at L5 matters because it governs how load and rotation transfer from the lumbar spine into the sacrum, and it frames the mechanics behind common L5 to S1 pain generators. Degenerative spondylolisthesis and isthmic spondylolisthesis often declare themselves here, where pars interarticularis defects, disc height loss, and facet arthropathy can combine to alter sagittal alignment and narrow the lateral recess. This is a high-stakes segment. Educationally, this lateral view supports teaching in gross anatomy, spine biomechanics, and musculoskeletal radiology by matching what learners correlate on lateral lumbar radiographs and sagittal CT or MRI, including the lumbosacral angle and disc space at L5 to S1. It also suits surgical planning figures for posterior lumbar decompression and fusion discussions, where facet joint anatomy and the relationship of L5 to the sacral promontory need to be communicated cleanly. Anatomical accuracy verified by SciePro's Medical Advisory Board.