Espiral AtlasTypical lumbar vertebra (L1–L5)
vertebra lumbalis
Study entry
Parts
Very bulky body, because it bears more weight. Transverse (costiform) processes pointing backward, upward and laterally, with the accessory process at the base; mammillary processes behind the superior articular processes. Articular facets sagittal above, becoming coronal toward L5–S1. L5, the largest movable vertebra, has the body taller in front and accounts for the lumbosacral angle. Areas painted on L3.
Joints
With neighbors through the discs and the zygapophysial joints, which favor flexion and extension, allow lateral flexion and prevent rotation; L5 with the base of the sacrum.
Palpation
The spinous processes are large and can be seen when the trunk is flexed. The line joining the highest points of the iliac crests passes through the spinous process of L4 and the L4–L5 disc, a reference for lumbar puncture; that of L2 helps estimate the end of the cord.
Source: cap. 2, «Vértebras: vértebras lumbares» y tabla 2-3