Assertion: medulla's matter | /r/HasProperty | replaced by decussation
Facets:
Source sentences:
text: The spinal cord gray matter is replaced by the motor (crossing of corticospinal fibers) decussation; the central gray matter enlarges; the posterolateral tract (dorsolateral fasciculus) and substantia gelatinosa of the spinal cord merge, respectively, into the spinal trigeminal tract and nucleus; and nuclei characteristic of the medulla appear.