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Mode of Signal Transmission and Its Analysis in the Central Nervous System
- Dr J.P.N. Mishra
The brain is a unique assembly of cells which unabatedly receives information, elaborates and perceives it, and makes decisions. At the same time, the brain in association with spinal chord can also take the initiative and act upon various sense organs to regulate their performance. To carry out its task of determining the many aspects of behaviour and controlling directly or indirectly the rest of body, the brain possesses an immense number of lines of communication provided by the nerve cells, known as 'neurons'.
Neurons are the fundamental units or the building blocks of the brain, and it is most important task to find out the meaning behind their signalling. Neurons occur in a variety of sizes and shapes (Figure 1), most of them consist of four parts (1) the cell body, (2) the dendrites, (3) the axon, and (4) the axon terminals.
The dendrites form a series of highly branched outgrowths from the cell body. The dendrites and the cell body are the sites of most of the specialized junctions where signals are received from other neurons.
The axon, sometimes also called a nerve fiber, is a single long extension from the cell body. The portion of the axon closest to the cell body plus the part of the cell body where the axon is joined is known as the initial segment. It is at the initial segment that are initiated the electric signals that then propagate away from the cell body along the axon. The axon may have branches called collaterals along its course, and near their ends both the axon and collaterals
तुलसी प्रज्ञा जनवरी-मार्च, 2000
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