機能学设计性实验报告.docVIP

神经干、肌膜动作电位和骨骼肌收缩同步观察 摘要 目的：通过同步记录神经干、肌肉膜动作电位和骨骼肌收缩，学习多信号记录技术。观察神经-肌接头兴奋传递和骨骼肌兴奋的电变化与收缩之间的时间关系以及各自的特点。 方法：通过微机生物信号采集处理系统，刺激离体蟾蜍坐骨神经腓肠肌标本，观察神经干、肌膜动作电位和骨骼肌收缩以及神经-肌接头兴奋传递和骨骼肌兴奋的电变化与收缩之间的时间关系，并观察标本在酸中毒和碱中毒情况下的结果。 结果：加入乳酸溶液时，阈刺激强度变大，加入NaHCO3溶液时，阈刺激强度变小。 结论：肌肉酸中毒，阈刺激强度变大，肌肉碱中毒，阈刺激强度变小。 关键词 动作电位、阈刺激、不应期、酸中毒、碱中毒 Abstract Purpose:Through the simultaneous recording of nerve, muscle membrane action potential and contraction of skeletal muscle, learning multiple signal recording technology. Observation of neuromuscular junction excitation transfer and skeletal muscle excitability and contraction of electrophysiological changes of the relationship between time and their characteristics. Method：Biological signal collecting and processing system by microcomputer, stimulation of isolated toad sciatic Nerve-gastrocnemius specimen, observation of neural stem, muscle membrane action potential and contraction of skeletal muscles and neuromuscular junction excitation transfer and skeletal muscle excitability and contraction of electrophysiological changes of the relationship between time, and the specimens were observed in acidosis and alkalosis results under the conditions of. Result: Adding lactic acid solution, the threshold stimulus intensity becomes large, joined the NaHCO3solution, the threshold stimulus intensity change small. Conclusion: Muscle acidosis, threshold stimulus intensity becomes large, muscular alkalosis, threshold stimulus intensity change small. Key word Action potential, threshold stimulus, Refractory period,　acidosis, alkali poisoning 引言 兴奋的运动神经通过局部电流将神经冲动传导至神经-肌接头，使接头前膜释放神经递质乙酰胆碱（Ach），Ach与接头后膜Ｍ受体结合使后膜去极化，后膜去极化至阈电位水平便爆发动作电位，进而引起肌肉的收缩。上述过程中，骨骼肌兴奋的电变化（ＡＰ）与收缩（长度与张力变化）是两种不同性质的生理过程，但又密切相关。当肌膜产生动作电位后，根据局部电流原理，ＡＰ可沿肌膜迅速传播，并经由横管膜进入肌细胞内到达三联体部位。ＡＰ形成的刺激使终池膜上的钙通道开放，贮存在终池内的Ca2+顺浓度差以易化扩散的方式经钙通道进入肌浆到达肌丝区域，使Ca2+与细肌丝的肌钙蛋白结合，引发肌丝滑行过程，结果是肌细胞的收缩。 材料与方法 （一）材料 实验动物　蟾蜍 实验药品　任氏液、2.5%NaHCO3，1%乳酸 实验器材　ＢＢ－３Ｇ屏蔽盒、针形引导电极、张力换能器、生物信号采集处理系统 （二）方法 １. 系统连接和仪器参数设置 张力换能器输入RM 6240 系统第一