Cooper Krone Exam 1 Practice

Lumbar vertebrae have distinct posterior projections that serve as muscle attachment points, setting them apart from other spinal regions. The two features that are unique to the lumbar area are the mammillary process on the posterior aspect of the superior articular process and the accessory process at the base of the transverse process. The mammillary process provides attachment sites for small back muscles such as the multifidus, helping stabilize the spine, while the accessory process anchors the intertransversarii muscles and associated ligaments, aiding lateral stability.

Other options point to features not characteristic of the lumbar region: transverse costal facets are a thoracic feature for rib articulation; an articular facet with the occipital bone occurs at the atlas–occipital region; and dorsal foramina relate to different vertebral regions (not a defining lumbar feature).