题干

健康成年人饮用1000mL清水后1﹣2小时内,尿量显著增多,而饮用等量的生理盐水后,尿量变化幅度不大,回答下列问题:

(1)饮用1000mL的清水后,尿流量增多的原因是细胞外液____ 下降,下丘脑分泌的____ 减少,____ 对水的重吸收减少.

(2)当膀胱中尿液充盈时,膀胱中的相应感受器就会感受到刺激,产生____ 并传递到脊髓腰段的排尿中枢,且能上传到大脑皮层,产生尿意.如果排尿条件不成熟,大脑能抑制脊髓排尿中枢,这体现了神经调节具有____ 的特点.

(3)如果某人胸部脊髓因外伤而截断,排尿反射可以完成吗?请简要说明原因____ .

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答案(点此获取答案解析)

渗透压,抗利尿激素,肾小管和集合管,神经冲动,分级调节,可以,排尿反射的反射弧还是完整的

同类题1

阅读理解

    There were smiling children all the way. Clearly they knew at what time the train passed their homes and they made it their business to stand along the railway, wave to complete strangers and cheer them up as they rushed towards Penang. Often whole families stood outside their homes and waved and smiled as if those on the trains were their favorite relatives. This is the simple village people of Malaysia. I was moved.

    I had always traveled to Malaysia by plane or car, so this was the first time I was on a train. I did not particularly relish the long train journey and had brought along a dozen magazines to read and reread. I looked about the train. There was not one familiar face. I sighed and sat down to read my Economics.

    It was not long before the train was across the Causeway and in Malaysia. Johore Baru was just another city like Singapore, so I was tired of looking at the crowds of people as they hurried past. As we went beyond the city, I watched the straight rows of rubber trees and miles and miles of green. Then the first village came into sight. Immediately I came alive; I decided to wave back.

    From then on my journey became interesting. I threw my magazines into the waste basket and decided to join in Malaysian life. Then everything came alive. The mountains seemed to speak to me. Even the trees were smiling. I stared at everything as if I was looking at it for the first time.

    The day passed fast and I even forgot to have my lunch until I felt hungry. I looked at my watch and was surprised that it was 3:00 pm. Soon the train pulled up at Butterworth. I looked at the people all around me. They all looked beautiful. When my uncle arrived with a smile, I threw my arms around him to give him a warm hug (拥抱). I had never done this before. He seemed surprised and then his weather-beaten face warmed up with a huge smile. We walked arm in arm to his car.

    I looked forward to the return journey.

同类题5

阅读文言文,回答问题。

(甲)

       若夫霪雨霏霏,连月不开,阴风怒号,浊浪排空;日星隐耀,山岳潜形;商旅不行,樯倾楫摧;薄暮冥冥,虎啸猿啼。登斯楼也,则有去国怀乡,忧谗畏讥,满目萧然,感极而悲者矣。

       至若春和景明,波澜不惊,上下天光,一碧万顷;沙鸥翔集,锦鳞游泳;岸芷汀兰,郁郁青青。而或长烟一空,皓月千里,浮光跃金,静影沉璧,渔歌互答,此乐何极!登斯楼也,则有心旷神怡,宠辱偕忘,把酒临风,其喜洋洋者矣。

       嗟夫!予尝求古仁人之心,或异二者之为,何哉?不以物喜,不以己悲;居庙堂之高则忧其民;处江湖之远则忧其君。是进亦忧,退亦忧。然则何时而乐耶?其必曰“先天下之忧而忧,后天下之乐而乐”乎。噫!微斯人,吾谁与归?

(节选自范仲淹《岳阳楼记》)

(乙)

      蝜蝂者,善负小虫也。行遇物,辄持取,印其首负之。背愈重,虽困剧不止也。其背甚涩,物积因不散,卒踬仆不能起。人或怜之,为去其负,苟能行,又持取如故。又好上高,极其力不已,至坠地死。

      今世之嗜取者,遇货不避,以厚其室,不知为己累也,唯恐其不积。及其怠而踬也,黜弃之,迁徙之,亦以病矣。苟能起,又不艾,日思高其位,大其禄,而贪取滋甚,以近于危坠,观前之死亡不知戒。虽其形魁然大者也,其名人也,而智则小虫也,亦足哀夫!

(选自柳宗元《蝜蝂传》)

      【注释】①困剧:非常困倦疲累。②因:因而。 ③踬仆:倒下。 ④货:货物。