Which of the following correctly describes the location of white and gray matter in the spinal cord?

• A. Both white and gray matter are evenly mixed throughout the spinal cord.
• B. Gray matter is found only on the outer surface of the spinal cord.
• C. White matter is located centrally, surrounded by gray matter.
• D. Gray matter is located centrally, surrounded by white matter.

Answer: (D)

Verified step by step guidance

1. Step 1: Begin by understanding the basic structure of the spinal cord. The spinal cord is composed of two types of tissue: gray matter and white matter, which differ in their composition and function.
2. Step 2: Gray matter primarily consists of neuron cell bodies, dendrites, and unmyelinated axons. It is responsible for processing and integrating information. In the spinal cord, gray matter is organized into a butterfly-shaped structure located centrally.
3. Step 3: White matter is composed of myelinated axons that form tracts for transmitting signals to and from the brain and other parts of the body. It surrounds the central gray matter in the spinal cord.
4. Step 4: Visualize the cross-sectional anatomy of the spinal cord. The central gray matter forms an 'H' or butterfly shape, while the white matter encases it, forming the outer layer.
5. Step 5: Based on this anatomical organization, the correct description is: 'Gray matter is located centrally, surrounded by white matter.' This arrangement allows the spinal cord to efficiently process and transmit neural signals.