Figure 1-1. Organization of the nervous system.
CELL ORGANIZATION OF THE NERVOUS SYSTEM
Only two principal kinds of cells exist in the nervous system: neurons and
neuroglia. Neuroglia cells (also called glial cells) act as connective tissue and function
in the roles of support and protection. Some of these cells twine around nerve cells or
line certain structures in the brain and spinal cord. Other neuroglia cells bind nervous
tissue to supporting structures and attach neurons to their blood vessels. Other small
neuroglia cells protect the central nervous system from disease by surrounding invading
microbes and clearing away debris. Clinically, these cells are important because they
are a common source of tumors of the nervous system. Neuron cells are nerve cells,
the basic unit that carries out the work of the nervous system. Impulses from one body
part to another body part are conducted by neurons.
Figure 1-2. Cells of the nervous system.