Neurons are specialized nerve cells which produce and carry nerve signals. Each neuron is composed of dendrites, a central cell body, and an axon. 

• The function of dendrites is to respond to stimuli by receiving incoming signals (like antennas for neurons) and direct them toward the cell body. 
• The cell body functions like a neuron’s headquarters, where it generates proteins and contains specialized organelles including granules, the nucleus, and Nissl bodies. 
• Axons function as highways, transmitting signals over long distances away from the cell body. 

In the central nervous system, there are 3 types of neuroglia: microglial cells, astrocytes, and oligodendrocytes. 

• Astrocytes are localized in the brain and spinal cord. They have complex structures resembling stars and function to maintain a suitable chemical environment for effective communication between neurons. 
• Oligodendrocytes wrap myelin around certain axons of neurons, influencing the speed of nerve impulse transmission. 
• Microglial cells play roles as scavenger cells in the brain, removing waste and debris from areas of injury or cell turnover. 

In the peripheral nervous system, the 3 main types of neuroglia are Schawn cells, enteric glia, and satellite cells. 

• Schawnn cells play a key role in generating myelin. 
• Satellite cells are found in the sensory and autonomic ganglia, and provide structural support to neurons. 
• Enteric glia are found in the enteric nervous system, and support the processes of the digestive system.