Axons are elongated nerve fibres that conduct nerve impulses often called electrical signals. These signals are the language understood by the nervous system. Like electrical signals, the neurons conduct impulses in milliseconds- very fast.
At times, the speed of conduction of nerve impulses may vary from one neuron to the other or from one individual to another depending on some other factors which could either be endogenic or exogenic to the said neuron. By endogenic factors, I mean those factors or conditions inherent in the neuron itself. They biologically determined as opposed to exogenic factors which are factors external to the neuron but still have significant influence on the speed of nerve impulse flow.
Moreover, nerve impulse flow as earlier said may be affected by myelination. This myelination is the extent to which myelin sheaths are bigger, larger and longer enough to cover the axons. Also, the myelin sheath themselves have their functions enhanced by the influence of some glial cells called oligodendrocytes in the central nervous system and schwann cells in the peripheral nervous system.
The more the myelin sheath and its fatty substances, those chemicals that enhance its function by wrapping around it , the more the efficay of nerver impulse flow. All the functions of the body system most oof which are regulated bry the nervous system most time depend s on the functions of the myelin sheaths. This can influence an organism’s irritability- mability to react to external stimuli, and reaction time in one way or the other.
Consider for instance your own brain when you hit your toe on a big stone which is quite painful. Normally, you are expected to feel the pain almost as instant as the hitting of your toe on the big stone since the nerve impulses that normally relay the sensation oof pain are relatively faster im their conduction of nerve impulses than when you only experienced a sense of touching an object. If you react slowly to that, there might be a neurological deficit.
In like manner intelligence or IQ may has a very positive correlation with myelination. This is to say explicitly that brain processing speed and overall conductance of nerve impulses related to processing of logic and creativity depends to some reasonable extent on how much myelination you have in your brain as regarding those brain areas the serve to process the domain of intelligence test in question.
This would mean an adequate neurological explanation to genius brains but also with regard to genetics and some other environmental factors.
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