Lumbar vertebrae
Vertebrae lumbales
The lumbar vertebrae are the five large, weight-bearing vertebrae of the lower back, lying below the thoracic spine and above the sacrum.
At a glance
- English
- Lumbar vertebrae
- Latin (TA2)
- Vertebrae lumbales
- System
- Bone
- Region
- Back
- In order
- From the vertebra l1 to the vertebra l5
About the lumbar vertebrae
The lumbar vertebrae are the five bones of the lower back, L1 to L5, lying below the ribs and above the sacrum. They are the largest vertebrae in the column because they bear the most weight. They are recognised by what they lack: there is no foramen in the transverse processes, as found in the neck, and no rib facets on the bodies, as found in the chest. A few people have four or six.
Each has a massive kidney-shaped body, broader across than it is deep from front to back. The pedicles are thick and run straight back from high on the body, and they widen and angle further outward towards L5; surgeons use them as a route into the body for screws or bone cement. The laminae are short and broad, the canal is triangular, and the spinous process is a thick, squared-off plate that juts straight back. The articular facets on the upper processes are hollow and face inward, gripping the convex, outward-facing facets of the vertebra above, an arrangement that favours bending forward and back over twisting.
Each transverse process is a long, slim bar that corresponds to a rib. Near their roots sit two small bumps, the mammillary process on the back of each upper articular process and the accessory process lower down, both anchoring deep back muscles. In the upper three vertebrae the transverse processes are horizontal and spring from the junction of pedicle and lamina; in the lower two they tilt slightly upward and arise further forward, from the pedicle and body.
The first and last members stand out. L1 marks the transpyloric plane, a level that crosses the pylorus, the hila of the kidneys and the origins of the coeliac trunk and superior mesenteric artery, and close to where the spinal cord ends. L5 is wedge-shaped to meet the sacrum and is by far the commonest site of spondylolysis, a defect in the bony arch, and of spondylolisthesis, the forward slip of one vertebra on the next.
Anthromica
See the lumbar vertebrae where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
