Functions of the human spine include supporting the body's weight, facilitating movement and flexibility and protecting other structures in the vulnerable spinal cord from injury, including the brain and inner organs. The spine consists of over 20 small bones, stacked vertically and connecting with other structures in the body, including nerves and muscles. The spine, in coordination with these other features, supports the life functions of organs and enables sensory perception, thought and locomotion.
Together, the 24 bones, or vertebrae, in the spine form the spinal column. These bones attach to each other through ligaments and tendons. Discs, which appear as spongy layers with soft gel, form protective layers of cushioning around each spinal bone, preventing friction and bone damage. Each vertebrae contains a hollow inner core, which houses nerves. These nerves extend from the brain throughout the body, sending important signals for movement and sensory perception.
The roomy interiors of vertebral cores allow nerve flexibility, while tough outer bony layers prevent nerve damage. The spine breaks down into three basic parts: thoracic, lumbar and cervical. The lumbar spine contains five to six vertebrae and supports the body's weight. The lumbar spine resides in the torso, consisting of 12 vertebrae and protecting organs. The cervical spine, with seven vertebrae, attaches to the brain, enabling nervous system functioning.