问题 单项选择题

大量出汗时尿量减少是由于

A.血浆晶体渗透压升高,ADH释放增多

B.血浆晶体渗透压降低,ADH释放减少

C.血量减少,血压下降

D.血浆胶体渗透压升高,ADH释放增多

E.血浆胶体渗透压升高,肾小球滤过率减少

答案

参考答案:A

解析:机体对水平衡的调节,机体排出的汗液是低渗的,因此,大量出汗引起的脱水,表现为高渗脱水。由于汗液中NaCl较血浆低,没有蛋白质,血浆渗透压升高主要是晶体渗透压升高。血浆晶体渗透压升高,刺激了下丘脑的渗透压感受器,引起抗利尿激素释放增加,使肾脏远曲小管和集合管对水的重吸收增加,导致尿液浓缩和尿量减少。此外,抗利尿激素也能增加髓袢升支粗段对NaCl的主动重吸收和内髓部集合管对尿素的通透性,提高了。肾髓质的渗透压梯度,也有利于尿液浓缩。

阅读理解

A tsunami(海啸) is a series of(一系列) huge waves that can cause great destruction(毁灭) when they hit a beach. Most tsunamis are caused by underwater earthquakes, but not all underwater earthquakes cause tsunamis. About 90 percent of all tsunamis take place in the Pacific Ocean, most of them are in Japan. A strong earthquake in the ocean near Japan caused a deadly tsunami on March 11,2011. As of April 25, the number of death had been raised to 14,133, and more than 13,346 people were listed as missing. The word “tsunami” comes from the Japanese word.

Many tsunamis could be found before they hit land with the use of modern technology. If you see the water drawback (后退) quickly and unexpectedly from a beach, run toward higher ground or inland -- there may be a tsunami coming. Also, if you are on the beach and there is an earthquake, it may have caused a tsunami, so run toward higher ground or inland. The first wave in a tsunami is often not the largest; if you experience one unusually-huge wave, go inland quickly -- even bigger waves could be coming soon. 

Do you know the story of the "angel(天使) of the beach"? Tilly, A 10-year-old English schoolgirl who saved the lives of hundreds of people in Phuket,Thailand in the Asian Tsunami of 2004 , by warning them a wall of water was about to strike(袭击), after learning about tsunamis in geography class. “Last term geography teacher Andrew Kearney taught us about earthquakes and how they can cause tsunamis,” Tilly said to the reporter.“I was on the beach and the water started to go funny. There were bubbles and the water went out all of a sudden. I recognised what was happening and had a feeling there was going to be a tsunami. I told mummy.”

小题1:An earthquake          may cause a tsunami.

A. in the city                  B. in the country             C. under the water

小题2:When the tsunami is coming, we should          .

A. run towards the higher place or inland   

B. run to the playground  

C.run into a house

小题3:Tilly saved hundreds of people’s life in        .

A. Japan                      B. Tailand                   C. the United Kingdom

小题4:Tilly recognised there would be a tsunami because          .

A. her geography teacher told her.    

B. she found the water drawback unusually quickly

C. she had a feeling about the earthquake

小题5:Which of the following statement is TRUE according to the passage?

A. The word “tsunami” is from Japanese because most recorded tsunamis in the world took place in Japan

B. Tsunami can only be found by modern technology before it hit the land.

C. Tsunami only happens in the Pacific Ocean

单项选择题