Question

bundles of axons in the central nervous system are known as horns. tracts. commissures. ganglia. nuclei.

Explanation:

• Horns: In the spinal cord, the gray matter is divided into regions called horns (dorsal, ventral, lateral). They are not bundles of axons.
• Tracts: In the central nervous system (CNS), bundles of axons with a common origin, destination, and function are called tracts. For example, the corticospinal tract.
• Commissures: These are tracts that connect the right and left sides of the CNS (e.g., corpus callosum in the brain). But the general term for bundles of axons in CNS is tracts.
• Ganglia: These are collections of neuron cell bodies in the peripheral nervous system (PNS), not axon bundles in CNS.
• Nuclei: These are clusters of neuron cell bodies in the CNS, not axon bundles.

Answer:

B. tracts.