Vertebra L4

The lumbar vertebra L4 (4th lumbar vertebra) is characterized by several distinct anatomical features:

• The vertebral body of L4 is larger and more robust compared to the upper lumbar vertebrae, reflecting its role in bearing a significant portion of the body's weight.

• The vertebral body is roughly cylindrical, with a slightly concave posterior surface and a more flattened anterior surface.

• The L4 vertebra has a vertebral foramen that is triangular in shape, providing passage for the spinal cord and associated structures.

• The pedicles of L4 are short and stout, projecting posteriorly from the vertebral body.

• The laminae are broad and thick, forming the posterior part of the vertebral arch. The transverse processes of L4 are long and slender, extending laterally and slightly posteriorly. These processes serve as attachment points for muscles and ligaments.

• The spinous process of L4 is short, thick, and nearly horizontal, providing leverage for the muscles that extend and rotate the spine.

• The superior and inferior articular processes of L4 are well-developed, with the superior articular facets facing medially and slightly posteriorly, and the inferior articular facets facing laterally and slightly anteriorly. These facets form the zygapophyseal joints with the adjacent vertebrae, contributing to the stability and flexibility of the lumbar spine.

• The pars interarticularis, the part of the vertebra between the superior and inferior articular processes, is a common site for stress fractures, particularly in athletes.