Between the vertebae of the lumbar spine anatomy are the discs. The discs are composed of two parts, a tough ligamentous outer ring called the annulus, and the softer center called the nucleus pulposis. Together they form a shock absorbing cushion between each pair of vertebra.
"bottom five vertebrae form the lumbar spine"
The first seven vertebrae make up the cervical spine. The next 12 vertebrae compose the thoracic spine, and the bottom five vertebrae form the lumbar spine.
The lower end of the lumbar spine is connected to the sacrum, which is made up of five fused vertebrae, and forms the posterior pelvis. At each side of the sacrum are the sacroiliac joints, where the sacrum connects to the bones of the pelvis.
"largest and strongest vertebrae in your spine"
The lumbar vertebrae are the largest and strongest vertebrae in your spine, because they must support the most weight. In the lumbar spine there are short pieces of bone that project to the right and left, from the pedicles of each vertebra, these are called transverse processes.
The transverse processes are connection points for the many ligaments and muscles that control the motion of, and support, the lumbar spine. There is another short piece of bone that projects straight back from the lamina that is called the spinous process.
When you run your hand down the middle of your back you can feel the tips of the spinous processes. These also are used as connections for muscles and ligaments that stabilize your spine and control the motion.
"run the entire length of your spine"
All of the vertebrae, with projections going in every direction, are connected together by ligaments. The anterior and posterior longitudinal ligaments run the entire length of your spine.
The anterior longitudinal ligament is connected to the front of each vertebral body and disc. The posterior longitudinal ligament is connected to the back of each vertebral body, inside the spinal canal.
The pedicles that project straight back from the body of the vertebra, and the lamina across the back of the spinal canal, are all connected together by a ligament called the ligamentum flavum.
"are all connected together"
The spinous processes that project toward the back are all connected together by the interspinous ligaments.
"far too complex to try and explain here"
Over the top of the ligaments are the muscles of the lumbar spine anatomy. There are several layers of muscle running in several directions that make it far too complex to try and explain here. There are small muscles, which run between each vertebra, connecting one to the next.
There are muscles that run obliquely, both up and down, along with larger muscles that run straight up and down your spine. All of the muscles are connected at various points on the vertebra, ribs, and pelvis, to hold you up right and control motion in every direction.