Nervous System — Flashcards

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The nervous system is the main control system of the body. It coordinates the activities of different organ systems by carrying information in the form of electrical impulses. It also controls volunta…

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A neuron, also called a nerve cell, is the basic structural and functional unit of the nervous system. Neurons number over a trillion in man and are specialised to transmit information rapidly from on…

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A neuron has four main parts: soma, dendrites, axon, and axon terminals. The soma is the main body, dendrites receive impulses, the axon carries impulses away, and axon terminals help in forming synap…

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The soma, also called cyton or cell body, is the star-shaped main body of the neuron. It contains a centrally placed large nucleus and Nissl's granules, which are rich in RNA.

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Dendrites are fibre-like structures branching out from the cyton. Their main function is to receive impulses and carry them towards the cell body.

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The axon is a long fibre-like structure extending from the cyton. It carries impulses away from the cell body and ends in axon terminals, which form synapses with other neurons or cells.

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The myelin sheath is a covering around many axons that insulates them and speeds up impulse transmission. It is secreted by Schwann cells, which remain attached to it. The myelin sheath is not a part …

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Nodes of Ranvier are regular gaps in the myelin sheath along the axon. They help in the rapid conduction of nerve impulses along the neuron.