The L3 to L4 level is found in the lower part of the spine in the small of the back, beneath the ribs and above the pelvis. This is the lumbar region. The vertebrae there are responsible for supporting the body's weight.Continue Reading
The lumbar vertebrae also allow people to bend and twist. There are five lumbar vertebrae, and L2 and L3 are found below the L1 vertebrae and above the L4 and L5 vertebrae.
Because of the burden they carry, these vertebrae are bigger and heavier than the other vertebrae in the spine. Unlike the other vertebrae, the lumbar vertebrae lack facets as well as the foramen transversarium, which is an opening in the vertebrae in the neck that allows the passage of blood vessels as well as the spinal nerves.
However, the lumbar vertebrae do have a triangular opening that allows for the passage of the spinal cord as well as the meninges and the cauda equina. This is a collection of nerves and nerve roots that resemble a horse's tail. The meninges are layers of tissue that protect the spinal cord.
The lumbar vertebrae also have several bony projections, called processes, that jut from the central body. These processes connect to muscles that control movement in the back, the trunk and the pelvis.Learn more about Nerves