Many regions of the brain can influence the input arriving at lower levels of the nervous system. This descending inhibition can be selective, with different regions of the brain inhibiting certain inputs to the spinal cord. Some regions reduce mechanoreceptive input, and others reduce noxious and warmth inputs. Descending inhibition can also reduce input from the skin while increasing input related to movement. Prominent regions of influence are those that themselves receive noxious input. For instance, the lateral reticular nuclei of the medulla oblongata cause a constant inhibition of input brought to the spinal cord by the nonmyelinated fibers. In ...(100 of 37287 words)