www.zeably.com/935/235775.html
www.zeably.com/62195/0648272.html
www.zeably.com/5509/4751.html
www.zeably.com/99/54.html
www.zeably.com/8066/61911943.html
www.zeably.com/3934/6559477.html
www.zeably.com/4811/88438.html
www.zeably.com/6166/70469.html
www.zeably.com/57/8138321.html
www.zeably.com/6909/97184.html
www.zeably.com/877/079388.html
www.zeably.com/146186/8535.html
www.zeably.com/957300/16.html
www.zeably.com/131258/95967.html
www.zeably.com/425808/4394840.html
www.zeably.com/4144/53215.html
www.zeably.com/0435/8545.html
www.zeably.com/4581/4060.html
www.zeably.com/435582/32.html
www.zeably.com/88056/217974.html
www.zeably.com/62/4980490.html
www.zeably.com/989/584.html
www.zeably.com/963671/850.html
www.zeably.com/54023/15729.html
www.zeably.com/38/99.html
www.zeably.com/946135/8142694.html
www.zeably.com/772/71809246.html
www.zeably.com/38/986898.html
www.zeably.com/145665/176.html
www.zeably.com/881693/999.html
www.zeably.com/32/58792.html
www.zeably.com/016735/0515.html
www.zeably.com/61/57290.html
www.zeably.com/894642/64.html
www.zeably.com/48744/97661.html
www.zeably.com/176795/740.html
www.zeably.com/96972/8245080.html
www.zeably.com/708903/69.html
www.zeably.com/567739/94211905.html
www.zeably.com/979458/07836940.html
www.zeably.com/946155/736339.html
www.zeably.com/4702/5942570.html
www.zeably.com/401/424613.html
www.zeably.com/5042/492694.html
www.zeably.com/693/40622995.html
www.zeably.com/43/10.html
www.zeably.com/661/33697815.html
www.zeably.com/56539/79134513.html
www.zeably.com/76051/92.html
www.zeably.com/442/03.html
www.zeably.com/8746/55.html
www.zeably.com/50/30.html
www.zeably.com/164/006722.html
www.zeably.com/18134/794.html
www.zeably.com/20802/63.html
www.zeably.com/39/530532.html
www.zeably.com/0813/97115.html
www.zeably.com/738/79670.html
www.zeably.com/526/57819131.html
www.zeably.com/7300/93.html
www.zeably.com/457019/2277.html
www.zeably.com/376919/36052.html
www.zeably.com/72689/46.html
www.zeably.com/87/959.html
www.zeably.com/46/484536.html
www.zeably.com/93/72654331.html
www.zeably.com/797/45.html
www.zeably.com/27/922.html
www.zeably.com/348989/06099395.html
www.zeably.com/7031/571.html
www.zeably.com/31/1228.html
www.zeably.com/021595/3095.html
www.zeably.com/84/48152942.html
www.zeably.com/223/98025949.html
www.zeably.com/051023/35730284.html
www.zeably.com/157399/20753470.html
www.zeably.com/82/3241.html
www.zeably.com/70821/55076695.html
www.zeably.com/087/54135.html
www.zeably.com/0731/2544535.html
www.zeably.com/015/682.html
www.zeably.com/687454/529368.html
www.zeably.com/288050/63.html
www.zeably.com/9531/330202.html
www.zeably.com/76747/851.html
www.zeably.com/03780/1133234.html
www.zeably.com/215301/69081254.html
www.zeably.com/40302/671.html
www.zeably.com/118/141528.html
www.zeably.com/3959/7739.html
www.zeably.com/48/3533.html
www.zeably.com/65/78.html
www.zeably.com/54/223022.html
www.zeably.com/6543/7359.html
www.zeably.com/11661/602476.html
www.zeably.com/65484/5804498.html
www.zeably.com/631/08589.html
www.zeably.com/319939/143.html
www.zeably.com/18/770572.html
www.zeably.com/560/8892.html
挖耳朵

咳咳!挖耳朵为什么想咳嗽?

蝌蚪五线谱 2018-07-13

  挖耳朵对很多人而言都是一种奇妙的享受,只不过在挖耳朵的时候,一些人会不由自主地咳嗽,这是怎么回事呢?

挖耳朵

  挖耳朵

这是一根迷了路的神经捣的鬼!

  神经我们都不陌生,它像通讯员一样连接着我们身体的最高指挥机构——大脑,以及其他执行具体任务的组织器官。这些负责通讯的神经细胞虽然看上去长得都差不多,其实它们也有不同的负责范围和分工。在我们的身体里,有十二对从大脑发出的神经,它们统称为颅神经,让我们在挖耳朵的时候咳嗽的就是其中的第十对神经——迷走神经。

颅神经

  颅神经示意图(图片来自网络)

  迷走神经是脑神经中身材最长、分布最广的神经。它是一种混合神经,包括有躯体感觉纤维、内脏感觉纤维、躯体运动纤维和内脏运动纤维,因而能负责多种信息的传递。

  正所谓能者多劳,迷走神经因其多样化的信息传递本领而广泛分布于身体的各个脏器、组织中,参与呼吸系统和消化系统中大部分器官以及心脏的感觉、运动以及腺体的分泌,并与交感神经一起调整人体的心率、呼吸、腺体分泌及肝、肾上腺等重要器官的血流量分布等。其中,咽喉部就是迷走神经的重要管辖范围之一。

迷走神经

  迷走神经分布示意图(图片来自网络)

  作为物质进出身体的交通要塞,咽喉一直都是我们身体关注的重点。在我们的喉头黏膜上分布有很多的迷走神经,这样当异物入侵时,它们就能及时通知大脑,下达咳嗽的指令,从而将异物咳出体外。

  如果迷走神经就走到这里为止倒也还好,可俗话说得好,路走多了总会迷路。作为身体里分布最广的神经,迷走神经也会有走错路的时候。在这趟信息传递线上,就有一些小的分支一不小心多走了一点,延伸到了外耳道,特别是外耳道后壁的皮肤下。于是,当我们挖耳朵时,外耳道下的迷走神经分支受到了刺激就会向大脑发出“异物入侵”的信号,而大脑一时间如果没有反应过来,就会误以为是喉头黏膜受到了刺激,于是立刻就下达了“咳!把异物咳出去”的指令,我们也就不由自主地咳了起来。

  说到这儿,你会不会觉得这个迷走神经挺不靠谱的,竟然连耳朵和喉咙它都分不开。不过这只是它在工作中犯的小错误,在大多数时候,迷走神经还是很靠谱而且很重要的。如果没有迷走神经的控制,交感神经引起的兴奋就会在心脏等重要器官上作用更长的时间,导致这些器官得不到休息,引起病变。而且,如果迷走神经罢工、病变了,还有可能诱发心力衰竭、心肌梗死、心律失常、晕厥、冠心病等心血管疾病。

  看在它有这么大作用的份上,挖耳朵引起的咳嗽,大家还是接受吧,或许这是沉默寡言的迷走神经在提醒我们它的存在呢。

责任编辑:sun

科普中国APP 科普中国微信 科普中国微博
蝌蚪五线谱
是中国科协为深入推进科普信息化建设而塑造的全新品牌,旨在以科普内容建设为重点,充分依托现有的传播渠道和平台,使科普信息化建设与传统科普深度融合,以公众关注度作为项目精准评估的标准,提升国家科普公共服务水平。

猜你喜欢