The anatomy of the nervous system, from the standpoint of development and function . EM M, interesting story. According to this author contractile tissue develops beforeany trace oi the nervous system appears. In sponges, which arc devoid ofnervous elements, the oscula open and close in response to appropriate movements are brought aboul by a contractile tissue no1 unlike moothmuscle. The active element or effector is thus the first to make it- appearanceand at this stage is brought into action by direct stimulation. Nexl in the orderof development is the sensory cell, derived fro
The anatomy of the nervous system, from the standpoint of development and function . EM M, interesting story. According to this author contractile tissue develops beforeany trace oi the nervous system appears. In sponges, which arc devoid ofnervous elements, the oscula open and close in response to appropriate movements are brought aboul by a contractile tissue no1 unlike moothmuscle. The active element or effector is thus the first to make it- appearanceand at this stage is brought into action by direct stimulation. Nexl in the orderof development is the sensory cell, derived from the epithelium in the neigh-borhood of an effector, and specially differentiated to receive stimuli and transmit them to the underlying muscle (Fig. 1, I)). This stage of development i-reached by such ccelenterates as the sea-anemones. The advantage whichthese forms derive from the specialized sensory cells or receptors is -ten in thecharacter of their responses, which arc more rapid than those of sponges. Such Cerebral ganglion v Esophageal connectivePharynx Ventral nerve cord.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectnervoussystem, bookye
