Fifth lumbar vertebra at a glance
- Also called
- L5
- What it is
- The fifth of the five lumbar vertebrae, labelled L5, in the lower back.
- Location
- Lies at the base of the lumbar spine between L4 and the sacrum.
- Function
- Bears the weight of the upper body and allows flexion and extension of the lower back.
- Body system
- Skeletal · single, midline structure
- FMA ID
- FMA13076 (Foundational Model of Anatomy)
Key facts
- It has the largest body of the lumbar vertebrae; the body is taller in front, which helps create the lumbosacral angle.
- Articulates below with the base of the sacrum at the L5-S1 junction, where the weight of the trunk is transferred to the pelvis.
Clinical relevance
Spondylolisthesis (forward slippage of one vertebra on another) from a pars interarticularis defect is most common at L5-S1; the degenerative form is most common at L4-L5.
Structures next to the fifth lumbar vertebra
The nearest named structures in the 3D model, measured from the centre of each part:
- Intervertebral disk of fifth lumbar vertebra · skeletal
- Intervertebral disk of fourth lumbar vertebra · skeletal
- Fourth lumbar vertebra · skeletal
- Common iliac vein · cardiovascular
- Superior rectal vein · cardiovascular
- Common iliac artery · cardiovascular
- Intervertebral disk of third lumbar vertebra · skeletal
- Interspinales lumborum · muscular
- Superior rectal artery · cardiovascular
- Internal iliac artery · cardiovascular
References
- Foundational Model of Anatomy: Fifth lumbar vertebra (FMA13076). EMBL-EBI Ontology Lookup Service.
- OpenStax. Anatomy and Physiology 2e, §7.1 Divisions of the Skeletal System. Rice University, 2022.
- Mitsuhashi N. et al. (2009). BodyParts3D: 3D structure database for anatomical concepts. Nucleic Acids Research 37, D782–D785. Data © The Database Center for Life Science, CC BY 4.0.
Related anatomy
Explore the whole body in the interactive 3D human anatomy model, or browse the A–Z list of human structures.