Neuron

Neurons (also spelled neurones or called nerve cells) are the primary cells of the nervous system.

Adaptations to carrying action potentials

The narrow cross-section of axons and dendrites lessens the metabolic expense of carrying action potentials, although thicker axons convey the impulses more rapidly, generally speaking.

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Many neurons have insulating sheaths of myelin around their axons. The sheaths are formed by glial cells: oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system. The sheath enables the action potentials to travel faster than in unmyelinated axons of the same diameter whilst simultaneously preventing short circiuts amoungst intersecting neurons. The myelin sheath in peripheral nerves normally runs along the axon in sections about 1 mm long, punctuated by unsheathed nodes of Ranvier. Multiple sclerosis is a neurological disorder which results from abnormal demyelination of peripheral nerves. Neurons with demyelinated axons do not conduct electrical signals properly.

Related Topics:
Myelin - Glia - Oligodendrocyte - Schwann cell - Faster - Nodes of Ranvier - Multiple sclerosis

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Neurons and glia make up the two chief cell types of the central nervous system. There are far more glial cells than neurons, and recent experimental results have suggested that glial cells play a vital role in information processing among neurons.

Related Topics:
Glia - Glial cells

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