PS263 Chapter 3: PS263 UNIT 3
Document Summary
Module 3. 1: structure of the vertebrate nervous system. The nervous system is 3-dimensional, so we need terms to describe it in that sense. The spinal cord is the part of the cns within the spinal column. It communicates with all the sense organs and muscles except those of the head. It"s a segmented structure: each segment has a sensory and motor nerve on its left and right side. Entering dorsal roots carry sensory information: cell bodies of the sensory neurons are in clusters of neurons outside the spinal cord, called dorsal root ganglia. Exiting ventral roots carry motor information: cell bodies of the motor neurons are inside the spinal cord. H-shaped, gray matter in the centre of the cord is packed with cell bodies and dendrites. White matter is made up of myelinated axons: many neurons from the gray matter of the spinal cord send axons to the brain through white matter.
