The spine has three main sections:
Cervical (neck), thoracic (mid-back), and lumbar (lower back).
The letter L – refers to lumbar. A spinal disc separates each vertebral body from the other. A L4-L5 disc, refers to the disc that is in between the L4 and L5 vertebral body.
- The disc absorbs compression within the spine
- The disc provides flexibility
- The disc protects from excessive motion
- The spinal nerves pass right behind the discs
