Masses of gray matter within the central nervous system are

The correct answer is: neuronal cell bodies, neuropil, and glial cells.

Explanation:

Nervous tissue can easily be classified in grey and white matter. Both of these matters are located in the Central Nervous System.

These specific names are given by the color these structures have. White matter consists mostly of axons, and is white because the axons are surrounded by myelin, which is a structure made of fat.

Grey matter is composed of the bodies of neuronal cells, neuropil and glial cells. The glial cells found in the grey matter are astrocytes and oligodendrocytes.

Answer & explanation:

The gray matter found in the structures of the CNS is distributed along with the white matter in the medulla, brainstem, brain and cerebellum.

Inside the CNS, the white matter is coated by the gray matter between structures, especially in the brain and cerebellum. In this interior, the gray matter forms masses that make up the central nuclei (cerebellum) and base nuclei (brain).