Final answer:
The central nervous system regions with a high concentration of axons are known as the white matter, consisting mainly of myelinated axons that give it a pale color, hosting important pathways for nerve signal transmission.
Step-by-step explanation:
Areas of the central nervous system that contain a high concentration of axons form the white matter. White matter is predominantly made up of myelinated axons, which are axons covered with a myelin sheath. This myelin is rich in lipids, giving white matter its characteristically pale coloration, which is in contrast to gray matter, where you find the majority of neuron cell bodies and dendrites.
White matter serves an important role in the nervous system, forming the connections between different parts of the nervous system and facilitating communication. In the brain and spinal cord, which comprise the central nervous system (CNS), white matter allows for the transmission of nerve signals across different areas. It also makes up the bulk of nerves in the peripheral nervous system, which reach out to various parts of the body.