• The nervous system is designed to coordinate & integrate functions of all body systems to maintain the organism in an optimal state .
  
  
• Receives sensory input from external environment and all the systems.
  
  
• It elicits the response through muscles and glands in these systems
  
  
• The coordination and integration function are shared with the endocrine sytem

Neurons: 

• Structural and functional units
  
  
• Characterized by:
  
  Excitability - ability to be activated.
  Conductivity- ability to propagate the impulse
  
  
• Consists of three functional domains:
  receptive- dendritic system
  integration & trophic - cell body
  transmission - axon

Neurons and neuroglia

Neuroglia:

• Provide physical and metabolic support to the neurons.
  
  
• Comprise:

1. Astrocytes;
2. Oligodendrocytes,
3. Microglial ependymal cells. 
4. schwann cells
5. Neuro satellite cells