The anatomy of the nervous system, from the standpoint of development and function . cytoplasm; B, from the facial nucleus of a dog, shows a partialdisappearance of the Nissl bodies (chromatolysis) resulting from section of the facial nerve.(Schafer.) metabolic activity of the cell, increasing during rest and decreasing as a resultof fatigue. They also undergo solution as a result of injury to the axon evenat a great distance from the cell, the so-called axon-reaction or chromatolysis(Fig. 27, B). The neurofibrils were first brought forcefully to the attention of neurologistsby Bethe (1903). T
The anatomy of the nervous system, from the standpoint of development and function . cytoplasm; B, from the facial nucleus of a dog, shows a partialdisappearance of the Nissl bodies (chromatolysis) resulting from section of the facial nerve.(Schafer.) metabolic activity of the cell, increasing during rest and decreasing as a resultof fatigue. They also undergo solution as a result of injury to the axon evenat a great distance from the cell, the so-called axon-reaction or chromatolysis(Fig. 27, B). The neurofibrils were first brought forcefully to the attention of neurologistsby Bethe (1903). These are delicate threads which run through the cytoplasmin every direction and extend into the axon and dendrites (Fig. 28). Theappearance of the fibrillae differs according to the technic employed in preparingthe tissue for microscopic examination. While in the preparations by Bethesmethod the fibrils do not appear to branch or anastomose with each other, thoseseen in Cajal preparations divide, and by anastomosing with each other form M I R( INS WI> M i Rl IN ? II \I\S 49. a true network. The fibrillar can be traced to the terminations oi the dendritesand axons. They have been looked upon by many as the chief elements involved in the conduction of the nerve impulse; Other elements such as pigment granules may De present. Mitochondriahave been described in nerve cells by Cowdrj 1191 11 and Rasmussen 11919 Interrelation of Neurons. In theccelenterates, as we have learned, a singlenerve-cell may receive the stimulus andtransmit it to the underlying in vertebrates the transmission of anerve impulse to an effector requiresa chain of at least two neurons, the im-pulse parsing from one neuron to the nextalong the chain. One of the most im-portant problems in neurology, there-fore, is this: How are the neurons re-lated to each other so that the impulsemay be propagated from one to theother? The place where two such unitscome into such functional relation isknown as a sy
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