Understanding Spinal Anatomy

Your Low Back

The lumbar spine bears the majority of the load for the spine. It holds the weight for any type of movement or activity the body performs. Therefore, the main purpose of the lumbar spine is to hold everything together, keep you standing upright, and help your body to function physically.

Vertebrae

The lumbar spine contains five vertebrae, L1 through L5. Think of these five vertebrae as the weight-bearers for your whole spine, or the major support area of the back. The outside of each vertebra consists of hard bone called cortical bone. The inside of the vertebra, or cancellous bone, is a porous bone structure. An extension of your spinal cord passes through a bony ring attached to each vertebra. This bony ring is made up of different parts:

• lamina
• spinous process
• transverse processes
• pedicle bone

The Disc

Between each vertebra, there is an intervertebral disc. The intervertebral disc is a connection between vertebrae that acts as a cushion for the body. These discs are “shock absorbers” for the pressure put upon your spine. The intervertebral disc is made up of two different parts:

• Annulus - an outer ring of fibers
• Nucleus - the center

The annulus is stronger than the nucleus to keep the entire vertebra intact. The soft nucleus consists mostly of water so it can absorb pressure.

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