试题与答案

兴奋在神经-肌肉接头传递中,胆碱酯酶清除的神经递质是() A.多巴胺 B.去甲肾上腺

题型:单项选择题 A1/A2型题

题目:

兴奋在神经-肌肉接头传递中,胆碱酯酶清除的神经递质是()

A.多巴胺

B.去甲肾上腺素

C.肾上腺素

D.乙酰胆碱

E.ATP

答案:

参考答案:D

解析:完成神经-骨骼肌接头的兴奋传递过程的神经递质是乙酰胆碱,乙酰胆碱可被终板膜上的胆碱酯酶迅速水解破坏,失去活性,结束兴奋传递过程。

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如图,绝缘水平地面上有宽L=0.4 m的匀强电场区域,场强E=6×105 N/C、方向水平向左,不带电的物块B静止在电场边缘的O点,带电量q=5×10-8 C、质量mA=1×10-2 kg的物块A在距O点s=2.25 m处以v0=5 m/s的 水平初速度向右运动,并与B发生碰撞,假设碰撞前后A,B构成的系统没有动能损失。A的质量是B的k(k>1)倍,A,B与地面间的动摩擦因数都为μ=0.2,物块均可视为质点,且A的电荷量始终不变,取g=10 m/s2

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