. Essentials of surgery; a textbook of surgery for student and graduate nurses and for those interested in the care of the sick . ortantconsiderations will be mentioned. The Neurone (Fig. 22) or nerve cell represents the essentialstructural and functional unit of the entire nervous neurone consists of a cell body with its protoplasm andnucleus, and certain processes: the short, many-brancheddendrites (1), and the single axis-cylinder process (2). NERVOUS SYSTEM 99 In general the dendrites receive nerve impulses from varioussources and transmit them toward the cell (afferent), and thea
. Essentials of surgery; a textbook of surgery for student and graduate nurses and for those interested in the care of the sick . ortantconsiderations will be mentioned. The Neurone (Fig. 22) or nerve cell represents the essentialstructural and functional unit of the entire nervous neurone consists of a cell body with its protoplasm andnucleus, and certain processes: the short, many-brancheddendrites (1), and the single axis-cylinder process (2). NERVOUS SYSTEM 99 In general the dendrites receive nerve impulses from varioussources and transmit them toward the cell (afferent), and theaxis-cylinder process transmits nerve impulses away from thecell (efferent). The life and function of the processes depend onthe neurone. Division of the fibre or destruction of the cell-body results in complete degeneration and loss of function of theperipheral portion of the process, including dependent structures,muscles, or sensory apparatus. If the cut ends are brought intocontact there results a regeneration of nerve fibres and later areturn of function. Such regeneration occurs also, provided fI ROLANDO P/fOJ£CnO/V ^. Fig. 23.—Cerebral cortex. the cut peripheral end is brought into contact with the centralends of axis-cylinder processes of any origin. Nerve cells are located in the grey matter which is foundin various regions of the central nervous system. For example : 1. The Cerebral cortex (Fig. 23) contains two maingroups of cells, (a) Association cells, whose axis-cylinder pro-cesses give communication between various areas of the of such cells causes no well-defined motor orsensory disturbances and these regions are therefore calledsilent areas. (6) Projection cells, whose axis-cylinder pro-cesses communicate with neurones at lower levels which give. 100 ESSENTIALS OF SURGERY FOR NURSES rise to motor nerves, or receive sensory stimuli from definiteregions. Destruction or lesions of such areas cause well-definedeffects characteristic for the regi
Size: 1982px × 1260px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishe, booksubjectsurgery
