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What does our back consist of?

The back is an intricate structure of bones, muscles, and other tissues that form the posterior of the body's trunk, from the neck to the pelvis. The centerpiece is the spinal column, which supports the weight of the upper body and contains and protects the spinal cord - the delicate structure of the nervous system that carries signals that control the body's movements and conveys its sensations. Stacked on top of one another are more than 30 bones - the vertebrae - that form the spinal column, also known as the spine. Each of these bones contains a circular hole that is stacked in register with the others, creating a channel that surrounds the spinal cord. The spinal cord descends from the base of the brain and extends in an adult to just below the rib cage. Small nerves (roots) enter and emerge from the spinal cord through spaces between the vertebrae. Because the bones of the spinal column continue growing long after the spinal cord reaches its full length in early childhood, the nerve roots to the lower back and legs extend many inches down the spinal column before exiting. Early anatomists named this large bundle of nerve roots the cauda equina, or horse's tail. The spaces between the vertebrae are maintained by round, spongy pads of cartilage called intervertebral discs that enable flexibility in the lower back and act much like shock absorbers throughout the spinal column to cushion the bones as the body moves. Bands of tissue known as ligaments and tendons hold the vertebrae in place and attach the muscles to the spinal column.

In sequence starting from the top, the spine has four regions:

The seven cervical or neck vertebrae, labeled C1-C7The 12 thoracic or upper back vertebrae, labeled T1-T12The five lumbar vertebrae, labeled L1-L5, which we know as the lower backThe sacrum and coccyx, a group of bones fused together at the base of the spine

The lumbar region of the back, where most back pain is felt, supports the weight of the upper body.

This answer is based on source information from The National Institute of Neurological Disorders and Strokes.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.