In any body locale where strength of interconnection is a requirement, dense connective tissues are found. Forces transmitted across tissues determine how the protein fibers are placed within each tissue type. For example, tendons and ligaments are cords of the body that must resist linear forces along their lengths.
The cervical spine in your neck is made up of seven bones called vertebrae, which are separated by discs filled with a cushioning gel-like substance. Your cervical discs both stabilize your neck and allow it to turn smoothly from side to side and bend forward to back.
The lumbar spine (lower back) is a remarkably complex structure. The L4-L5 are the two lowest vertebrae in the lumbar spine, and together with the attached disc, joints, nerves and soft tissues, it provides a variety of functions, including supporting the upper body and allowing motion in multiple directions.