Lab 10 (ƒ2) - Internal Organization of the Brain
Corticospinal Fibers - Overview
The corona radiata, internal capsule, cerebral peduncle, and pyramids form a continuous fiber system from the cerebral cortex down to the spinal cord. These fibers arise from and project to the whole extent of the cerebral cortex, course through the underlying white matter of the hemisphere and converge toward the diencephalon as a fan-shaped mass of fibers called the Corona Radiata. As you know, in the diencephalon these fibers make up the Internal Capsule. The internal capsule is comprised of all the fibers that go to and come from the cerebral cortex and link it to other levels of the neuroaxis. Below the level of the thalamus, corticofugal fiber systems (fibers that move away from the cortex) make up the Cerebral Peduncle of the midbrain (also known as crus cerebri). Further down, in the brainstem, these fibers make up the Pyramids.