Which region of the spine has the smallest disc height and nucleus pulposus?

• A. Cervical
• B. Thoracic
• C. Lumbar
• D. Sacral

Answer: (B)

The thoracic region of the spine is characterized by the smallest disc height and nucleus pulposus when compared to other spinal regions. This is due to several anatomical and functional factors.

In the thoracic spine, the vertebral bodies are smaller than those in the lumbar region, leading to flatter intervertebral discs. The thoracic discs tend to be more uniformly shaped and correspond with the less mobile nature of the thoracic spine, which is primarily influenced by the rib cage. The thoracic vertebrae are designed to provide stability and support to the rib cage, which protects vital organs in the chest and limits the overall range of motion compared to the cervical and lumbar regions.

Additionally, the nucleus pulposus, which is the gel-like center of the intervertebral disc, is relatively smaller in the thoracic region due to the lower compressive loads and reduced mobility when compared to the cervical and lumbar regions. This anatomical structure aligns with the functional demands placed on the thoracic spine, emphasizing stability over flexibility.

In summary, it is the thoracic spine that features the smallest disc height and nucleus pulposus, attributed to its unique structure and function within the vertebral column.