Projection

(pro-jek’ -shun) [pro, before; jacere, to throw]. I. The act of throwing forward. 2. A part extending beyond the level of the surrounding surface. 3. The referring of impre ions made on the organs of sense to the position of the object producing them. P. -systems, the name given to the pathways connecting the cerebral cortex with the periphery. The first P. -system corresponds to the fibers pa ing through the corona radiata; the second, to the tracts proceeding downward to the gray matter from the third ventricle to the end of the spinal cord; the third, to the peripheral nerves. 526