Final answer:
Gray matter in the spinal cord contains neuronal cell bodies, their dendrites, and the proximal parts of axons.
Step-by-step explanation:
The matter in the spinal cord that contains neuronal cell bodies, their dendrites, and the proximal parts of axons is gray matter. Gray matter is made up mainly of cell bodies of neurons, including interneurons and motor neurons. It is surrounded by white matter, which consists mainly of myelinated axons of motor and sensory neurons.