Exam 4 Review:  Chapter 12:  White Matter in the Brain

association fibers - The various interneuron processes (axons and dendrites) which transmit nerve impulses between the various gyri and nuclei within a single cerebral hemisphere.

commissural fibers - The various interneuron processes (axons and dendrites) which transmit nerve impulses from the various gyri and nuclei within a single cerebral hemisphere to corresponding locations in the opposite hemisphere; e.g., many of the fibers in the corpus callosum and anterior and posterior commissures.

projection fibers - The various interneuron processes (axons and dendrites) which transmit nerve impulses from the various gyri and nuclei within the cerebral hemispheres to various locations in other parts of the brain and spinal cord; e.g., the various ascending and descending tracts of white matter connecting the cerebrum to the rest of the CNS.

corpus callosum - The arched bridge of commissural white fibers, situated above the thalamus, which forms the roof of the lateral and third ventricles and which connects the two cerebral hemispheres, allowing communication between the right and left sides of the brain.

List

5. Three types of myelinated fibers bundled into tracts that make up the white matter in the cerebrum and their functions, in terms of where they transmit their nerve impulses.