Final answer:
The diameter of the spinal cord is approximately B. 1/2 inch. It is a crucial part of the central nervous system, protected within the backbone and comprises both gray and white matter.
Step-by-step explanation:
The approximate diameter of the spinal cord is B. 1/2 inch.
The spinal cord is a major component of the central nervous system, running from the brainstem down the center of the spine to the pelvis, and is encased by the vertebrae for protection.
The vertebral column has holes for the spinal nerves to pass through.
A cross-section view of the spinal cord reveals gray matter with cell bodies and interneurons, along with white matter containing axons.