Nerve Cell, a form of animal cell found in the gray nervous matter of the nervous centres (see Ganglion), and also in the peripheral expansion of some of the cranial nerves. Nerve cells are rounded or ovoid-shaped bodies, often with slender, elongated, tapering or branching processes extending from their periphery in various directions. They vary in size from 1/4000 to 1/300 of an inch in diameter. They consist of a soft granular substance, usually containing a considerable quantity of gray pigment, and a well defined round or oval nucleus, with a large and distinct nucleolus. Their branching processes often become continuous with the ultimate nerve fibres, which are mingled in profusion with the nerve cells in the gray substance of nervous centres. They are regarded as the most important anatomical elements of the nervous centres, where nervous power originates, or the nervous impressions are finally received.
Nerve Cells from the Retina of the Ox, magnified 350 times.