Anatomy Practice Exam

What is primarily found in the gray matter of the nervous system?

1. Myelinated axons

2. Neuronal cell bodies

3. Glial cells only

4. Unmyelinated fibers

The correct answer is: Neuronal cell bodies

In the gray matter of the nervous system, neuronal cell bodies are the primary components. Gray matter is characterized by the presence of these cell bodies, which are responsible for processing and integrating information. This is where synaptic connections occur, enabling communication between neurons. Within the gray matter, you will also find dendrites and unmyelinated fibers, which contribute to the overall function of these neurons. The concentration of cell bodies in gray matter distinguishes it from white matter, where myelinated axons are predominantly found, allowing for faster transmission of nerve impulses over longer distances. Glial cells, which support and protect neurons, are present in both gray and white matter. However, they are not the primary feature of gray matter. The distinction lies in the fact that gray matter serves as the processing center of the brain and spinal cord, whereas white matter acts as the communication highway, facilitating the conduction of signals between different areas. Therefore, however glial cells and unmyelinated fibers contribute to the nervous system's function, it is the neuronal cell bodies that define the gray matter's anatomy and role in processing information.