Which cavity contains the spinal cord?

The spinal cavity, also known as the vertebral cavity, is the space within the vertebral column that houses the spinal cord. This cavity extends from the base of the skull down to the lower back, providing a protective encasement for the spinal cord, which is a critical part of the central nervous system. The spinal cord transmits signals between the brain and the rest of the body, making its protection vital for nervous system functions.

In contrast, the thoracic cavity primarily contains the lungs and heart, the cranial cavity contains the brain, and the pelvic cavity houses reproductive organs and parts of the digestive system. None of these cavities contain the spinal cord, underscoring the uniqueness of the spinal cavity in this context. Therefore, identifying the spinal cavity as the correct answer highlights its specific and crucial role in housing the spinal cord.