How did Santiago Ramon y Cajal (1906) famous neuroanatomical drawings of the nervous system contribute to our current understanding of the cellular wiring of the nervous system? A. Distinguish the morphological difference between neurons and glia and list their respective classifications based on morphology or shape. B. Which glia are involved in myelination in the PNS and which are in the CNS? C. Of the four major neuronal shapes in A (above), a. which two make up the spinal reflex afferents? b. which two make up the spinal reflex efferents? c. which is/are uniquely found in the retina?