part of part of Homo sapiens lumbar vertebra 5 process of vertebra mammillary process of fifth lumbar vertebra 2026-03-19T00:00:00Z A process of vertebra located on the posterior aspect of the superior articular process of the fifth lumbar vertebra, forming the most inferior of the lumbar mammillary processes. It is especially prominent at this level, providing multifidus attachment and forming part of the lumbosacral articular region adjacent to the sacral ala. David Osumi-Sutherland