Function: stimuli reception, electrical impulses generation and conduction, integrating communications network
Location: central nervous system and peripheral nervous system
Origin: neuroectoderm: neural crest and neural tube
Function: motor neurons - convey impulses from receptors to the central nervous system; interneurons (internuncial, intercalated, central) - communicating and integrating network between sensory and motor neurons
Location: gray matter of brain and spinal cord, peripheral ganglia
Function: receptors for the special senses (taste, smell, hearing, sight and equilibrium)
Location: retina, ganglia of the vestibularcochlear nerve (cranial nerve VIII).
Function: sensory neurons- convey impulses from receptors to the central nervous system
Location: dorsal root ganglia
Function: releasing of neurosecretions, co-operation between the nervous system and endocrine system in the regulation of the function of internal organs.
Location: supraoptic and paraventricular nuclei of the hypothalamus
Function: physical support, protection, electrical insulation, and metabolic exchange pathways between vascular and nervous systems.
Function: electrical insulation, maintaining metabolic exchange and microenvironment around the neuronal body and processes
Location: myelinated and unmyelinated nerves, ganglia
Function: formation of the blood-brain barrier, movement of metabolites and wastes
Location: gray matter (protoplasmic astrocytes) and white matter (fibrous astrocytes)
Function: fluid transport, secretion, and barrier
Location: lining cavities of central nervous system
Function: phagocytotic cells.
Location: central nervous system, especially in regions of injury and decease
Origin: bone marrow, mononuclear phagocytic system