Anatomy Practice Exam

What characterizes gray matter in the central nervous system?

1. Consists mainly of myelinated axons

2. Has a white appearance with the naked eye

3. Comprised mainly of neuronal cell bodies

4. Acts as a primary conduit for reflex actions

The correct answer is: Comprised mainly of neuronal cell bodies

Gray matter in the central nervous system is primarily characterized by being comprised mainly of neuronal cell bodies. Unlike white matter, which contains a high density of myelinated axons that facilitate communication between different regions of the brain and spinal cord, gray matter is where the processing and integration of information occur. It houses the cell bodies of neurons, dendrites, and unmyelinated axons, making it essential for functions such as muscle control, sensory perception, and higher cognitive functions. The presence of neuronal cell bodies in gray matter is crucial for the formation of synapses where neural communication takes place. This region also contains glial cells, which support and protect neurons. Thus, the defining characteristic of gray matter is its composition, which is fundamentally linked to its role in the central nervous system’s functionality and processing capabilities.