projection fibers in the brain mainly connect what
Projection fiber The projection fibers consist of efferent and afferent fibers uniting the cortex with the lower parts of the brain and with the spinal cord. In human neuroanatomy, bundles of axons (nerve fibres) called tracts, within the brain, can be categorized by their function into association fibers, projection fibers, and commissural fibers.
Corpus callosum The corpus callosum (Latin for "tough body"), also callosal commissure, is a wide, thick, nerve tract consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental mammals.[1] It spans part of the longitudinal fissure, connects the left and right cerebral hemispheres, enabling communication between them. It is the largest white matter structure in the human brain, about ten centimetres in length and consisting of 200â€“300 million axonal projections.[2][3]