Which cavity is formed by the bones of the vertebral column and contains the spinal cord and the medulla oblongata?

• A. Cranial cavity
• B. Mediastinum
• C. Pleural
• D. Spinal cavity

Answer: (D)

The main idea is that cavities are spaces formed by bones that contain the main organs they protect. The vertebral column creates the spinal cavity, a long hollow canal that runs inside the spine and protects the spinal cord as it passes from the brainstem downward. This cavity is distinct from the cranial cavity, which is formed by the skull and houses the brain, including the brainstem at its upper end. The spinal cavity begins where the brain transitions to the spinal cord at the foramen magnum and remains continuous with the cranial cavity. The other options refer to different regions: the mediastinum and the pleural spaces are in the thoracic cavity and around the lungs, while the cranial cavity is formed by the skull. Although the medulla oblongata is part of the brainstem, it resides within the cranial cavity, and the spinal cavity contains the spinal cord. Thus, the space formed by the vertebral column that houses the spinal cord is the spinal cavity.