Which feature is a hallmark of lumbar vertebrae?

Which feature is a hallmark of lumbar vertebrae?

• A. Spinous processes that are bifid
• B. Foramina transversaria
• C. Mamillary process
• D. Costal facets on the body

Answer: (C)

Lumbar vertebrae are identified by a mammillary process on the posterior aspect of the superior articular process. This small bump serves as a muscle attachment site for deep back muscles and is a reliable landmark that differentiates lumbar from other regions. The presence of a mammillary process reflects the lumbar spine’s need for strong muscular stabilization and limited rotational capacity. Other features point to different regions: bifid spinous processes are characteristic of the cervical spine, especially mid-cervical levels; foramina transversaria are unique to the cervical vertebrae and carry the vertebral arteries; and costal facets on the body (along with transverse costal facets) are found in the thoracic spine for rib articulation.

Lumbar vertebrae are identified by a mammillary process on the posterior aspect of the superior articular process. This small bump serves as a muscle attachment site for deep back muscles and is a reliable landmark that differentiates lumbar from other regions. The presence of a mammillary process reflects the lumbar spine’s need for strong muscular stabilization and limited rotational capacity.

Other features point to different regions: bifid spinous processes are characteristic of the cervical spine, especially mid-cervical levels; foramina transversaria are unique to the cervical vertebrae and carry the vertebral arteries; and costal facets on the body (along with transverse costal facets) are found in the thoracic spine for rib articulation.