Neuron and it's communication



Neuron:
              What we thinking in our mental life involves the activities of the nervous system. There are 100 billions neurons in our nervous system, which contain the genetic material in the form of chromosomes.
Neurons have large number of extensions called dendrites. They look like branches or spikes extending out from cell body. Dendrites receive the chemical massage from other neurons. Dendrites are connected to the cell body. The cell body another part is connected which is called as the axon. The main function of axon is transfer the electrochemical signal to the other neurons, the length of axon as much as three feet. [1]



 Action potential:
          When chemicals contact the surface of a neuron, they change the balance of ions the inside and outside of the cell membrane. When this change reaches a threshold level, this effect runs across the cell's membrane to the axon. When it reaches the axon, it initiates the action potential, which is a rapidly moving exchange of ions.
The surface of the axon contains hundreds of thousands of miniscule mechanisms called ion channels. When the charge enters the axon, the ion channels at the base of the axon allow positively charged ions to enter the axon, changing the electrical balance between inside and outside. This causes the next group of ion channels to do the same, while other channels return positive ions to the outside and so on all the way down axon. The action potential travels at a rate of 1.2 to 250 miles per hour.

Synapse:
When the action potential reaches the axon ending, it causes tiny bubbles of chemicals
called vesicles to release their contents into the synaptic gap. These chemicals are called
neurotransmitters. These sail across the gap to the next neuron, where they find special places on
the cell membrane of the next neuron called receptor sites.









            The neurotransmitter acts like a little key, and the receptor site like a little lock. When they meet, they open a passage way for ions, which then change the balance of ions on the outside and inside the next neuron, and over all process start again. While most neurotransmitters are excitatory i.e. they excite the next neuron there are also inhibitory neurotransmitters. These make it more difficult for the excitatory neurotransmitters to have their effect.

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