Nervous system in human which either located inside the bony structure of spinal column as well as cranium, or outside of these bony structures consist of a tiny cells so called “Neuron” and “Glial cell” as a structural unit. Each neuron has an architecture that consists of a “Cell body”, and two sets of additional compartments called “Processes.
These processes which extend from the cell body; so called “Axon” and “Dendrites”; which extend in one, two, and/or many directions. The way of electrical currents indentifies dendrites from “Functional denderites” in the body. Some axon and functional dendrites are bare; and some others covered by lipid coverage called “Myelin coverage”. Ramony Cajal the father of modern neuroscience has shown the structural unit of the brain for first time under the microscope 1890.
Where an axon meets a cell body and/or dendrite of a second neuron was called “Synapse”; on which an electric current may pass into the second neuron via chemical molecules called “Neurotransmitters”. These “Neurotransmitters” may show excitatory and/or inhibitory properties.
Meeting the second neuron with the first one form a close circuit; establish a “Functional Unit” of the nervous system. Electrical current pass through the nerve fiber in one way only; so stimulation of the first neuron pass into the second one; then stimulate the first in turn; establishing an oscillatory circuit in the functional unit.
Immediate memory shows an example of such an oscillatory circuit; on which a piece of information may oscillate for a short period. This one way electric current resembles one way current in an analog, and/or transistor diode as well digital chips in electronic processor; explaining the nature of a processing unit in the brain.
In the nerve fibers of axon and/or functional dendrites negative ions of chloride and proteins gather inside; whereas the positive ions of sodium outside produce a voltage difference. Such position was called “Resting potential”; and stimulation of the nerve fiber via physical and/or chemical stimuli may produce an “Action potential”, on which sodium channels open in the nerve membrane and then replace with potassium.
The voltage changes within the action potential can be recorded using single unit recording technique. Action potential release neurotransmitters from nerve terminal into the synaptic cliff; the neurotransmitters then site on own receptors at the second neurons either exiting or inhibiting them. When these events happen in huge range at the neural pools make sense that how brain processing nuclei were work.
Alan Hodgkin and Andrew Huxley won the noble prize for discovering the mechanism of nerve impulse transmission for first time in the giant axon of the squid.
In conclusion whole human nervous system operate via huge communications among structural as well as functional units to mange not only movements of both skeletal and visceral muscles, but also receive all information from both surrounding environments and memory storage to process in different neuronal pools to reach to emotional stage of sorrow and/or pleasure, perception, cognation, vocalization, and creation in the mind machine as Professor Colin Blakemore mentions.
