Synonyms: lumbar spine
The lumbar vertebra is part of the human vertebral column. It consists of 5 individual bones, the lumbar vertebrae (Vertebrae lumbales), which are given consecutive numbers from the cranial to the caudal direction as LV1 - LV5. The lumbar vertebra is the lowest section of the vertebral column between the thoracic vertebra and the sacrum (Os sacrum).
The vertebral bodies of the lumbar vertebrae have a common basic shape. In contrast to the vertebrae of the other sections of the column, they are characterized by their particular size and their bean-like basic shape. The sagittal diameter of the lumbar vertebral body is smaller than the transverse.
You can recognize the following structural elements of the lumbar vertebrae:
From here, the vertebral processes (Processus vertebrae) are annexed laterally and dorsally.
In the area of the lumbar vertebra, the spinous processes are covered by the back muscles, and you can palpate them in the deepening between the muscle curvatures.
The vertebral foramen (Foramen vertebrale) is surrounded by the vertebral body as well as the vertebral arch, and it forms the space for the spinal cord (Medulla spinalis) with its integuments, vessels, and nerves. In the spinal canal of the lumbar vertebra, you cannot find any spinal cord from the first or second vertebra onward, but the Cauda equina.
The array of the individual vertebral foramens as a whole forms the spinal canal (Canalis vertebralis). Here, the intervertebral foramen (Foramen interverebrale) remains open between two vertebrae for the passage of the respective spinal nerves. The bony delimitation is formed by the pedicles of the vertebral arches (Pediculi arcus vertebrae) that are slightly withdrawn cranially and caudally, so that the Incisurae vertebrales inferiores et superiores can form.
The spinous processes are aligned straight to the back in the area of the lumbar vertebra. Therefore, the spinal canal is closed just by connective tissue here, which makes it very accessible for a puncture.
The transverse processes of the lumbar vertebra, also called costal processes, are relatively long and can also be seen as rudimentary rib according to their name. The actual transverse processes, the accessory processes lie dorsal to the costal processes and are rather weakly developed.
The joint surfaces of the lumbar vertebrae are mainly sagitally oriented. The sole exception is the fifth lumbar vertebra, whose joint surface almost is in the frontal plane. On the back of the superior articular processes, you can find the mammillary processes.
The number of lumbar vertebrae in the animal kingdom is varying a lot. Also within the species, the number can be different between the races.
Tags: Spinal column
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