1、第二节神经系统的结构与功能,蛙坐骨神经腓肠肌标本电刺激实验,适宜刺激,神经纤维的某一段(未刺激),动作电位的产生,机理:细胞膜对Na和K的通透性不同,K扩散到膜外,机理:受到刺激后Na通道打开,膜外Na大量内流,机理:在Na通道打开之后,Na通道再次关闭,K通道打开,K大量外流,神经冲动的产生神经纤维某点刺激前后的变化,静息时神经细胞膜内外离子浓度,注: A- 表示有机负离子,离子学说,Na+,细胞膜内,细胞膜外,Na+,Na+,Na+,Na+,K+,K+,K+,K+,K+,K+,Na+,Na+,K+,K+,Na+,Na+,K+,Na+,K+,K+,K+,K+,Na+,Na+,Na+,Na+,
2、Na+,Na+,Na+,Na+,Na+,K+,K+,K+,K+,K+,K+,K+,K+,高Na+,高K+,外正内负,cl-,cl-,cl-,cl-,cl-,cl-,钠离子通道,钾离子通道,Na+,K+,K+,K+,Na+,Na+,Na+,Na+,Na+,K+,K+,K+,K+,K+,K+,K+,K+,K+,K+,K+,离子学说,K+,K+,K+,Na+,Na+,Na+,Na+,Na+,Na+,Na+,K+,K+,K+,A B,细胞膜内,细胞膜外,外负内正,离子学说,A B,Na+,Na+,Na+,Na+,Na+,K+,K+,K+,Na+,Na+,Na+,K+,Na+,K+,K+,Na+,Na+
3、,Na+,Na+,Na+,Na+,Na+,Na+,K+,K+,K+,K+,K+,K+,K+,高Na+,高K+,cl-,cl-,cl-,cl-,cl-,cl-,钠离子通道,钾离子通道,Na+,K+,K+,K+,Na+,Na+,Na+,Na+,Na+,K+,K+,K+,K+,K+,K+,K+,K+,K+,K+,K+,K+,Na+,Na+,Na+,Na+,Na+,Na+,Na+,K+,Na+,K+,K+,K+,Na+,Na+,K+,外正内负,K+,K+,K+,K+,K+,K+,Na+,Na+,Na+,某一段神经纤维,A B,细胞膜内,细胞膜外,外负内正,离子学说,A B,Na+,Na+,Na+,Na
4、+,Na+,K+,K+,K+,Na+,Na+,Na+,K+,Na+,K+,K+,Na+,Na+,Na+,Na+,Na+,Na+,Na+,Na+,K+,K+,K+,K+,K+,K+,K+,高Na+,高K+,cl-,cl-,cl-,cl-,cl-,cl-,钠离子通道,钾离子通道,Na+,K+,K+,K+,Na+,Na+,Na+,Na+,Na+,K+,K+,K+,K+,K+,K+,K+,K+,K+,K+,K+,K+,Na+,Na+,Na+,Na+,Na+,Na+,Na+,K+,Na+,K+,K+,K+,Na+,Na+,K+,外正内负,K+,K+,K+,K+,K+,K+,Na+,Na+,Na+,A B,一、神经元的结构二、神经冲动的产生1、产生机理(离子学说)2、区分概念: 极化、反极化、去极化、复极化,课堂小结,