Elements of human physiology (1907) Elements of human physiology elementsofhumanp05star Year: 1907 THE SPINAL COED 591 to send it on with increased energy, acting like a battery relay in a telegraphic circuit. In all cases where there is a distinction between the dendrites and the axon, the direction of conduc- tion seems to be in the dendrites towards the cell, cellulipetal, and in the axon away from the cell, celluHfugal. In bipolar cells, as in the spinal ganglia, it is impossible as a rule to draw any distinction between the two processes. If the nerve-cells serve as relays of energy, ner
Elements of human physiology (1907) Elements of human physiology elementsofhumanp05star Year: 1907 THE SPINAL COED 591 to send it on with increased energy, acting like a battery relay in a telegraphic circuit. In all cases where there is a distinction between the dendrites and the axon, the direction of conduc- tion seems to be in the dendrites towards the cell, cellulipetal, and in the axon away from the cell, celluHfugal. In bipolar cells, as in the spinal ganglia, it is impossible as a rule to draw any distinction between the two processes. If the nerve-cells serve as relays of energy, nervous activity must be associated with a using up of material in the cell; and many attempts have been made to discover his- tological evidences of nerve-cell activity. Of importance in Fig. 271. Cells from the oculomotor nuclei thirteen days after section of the nerve on one side, a, cell from healthy side ; b, cell from side on which nerve was divided (Flatau). this connection is the presence ivf the nerve-cells of certain bodies which are known as Nissl's granules. If a section of nervous tissue fixed with alcohol, formol, or corrosive sublimate be stamed with basic dyes such as methylene blue or toluidin blue, the bodies of the cells are seen to contain a number of coarse angular granules or masses arranged more or less symmetrically round the cell, and extending for a considerable distance along the dendrites (Fig. 271, a). The axon and that part of the cell from which it arises (the nerve-hillock) are quite free from these granules (cf. Fig. 269). As the result of stimulation, changes have been described both in these granules
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