问题 填空题

如图是肾单位结构示意图,请据图回答:

(1)写出结构名称:④______

(2)③内的液体是______;④内的液体是______.

(3)在尿的形成过程中⑤起的作用叫______作用.

(4)医生在检验某人的尿液时发现了较多的红细胞,可能是[③]______出现病变.

答案

(1)图示肾单位的结构示意图,从图中可以看出:①入球小动脉,②出球小动脉,③肾小球,④肾小囊,⑤肾小管.

(2)血液流经肾小球时没有发生气体交换的作用,只进行了过滤作用,因此图中[①]入球小动脉、[③]肾小球和[②]出球小动脉内流动的血液是动脉血.

(3)当血液流经肾小球时,血液中除血细胞和大分子的蛋白质外,其余的像水、无机盐、葡萄糖等小分子的物质被过滤到肾小囊腔中形成原尿;原尿在流经肾小管时,大部分水、全部葡萄糖和部分无机盐等经重吸收作用送回血液,剩下的像少量水、无机盐、尿素等物质形成尿.因此在尿的形成过程中⑤起的作用叫重吸收作用.

(4)当肾小球发生病变时,会导致肾小球的通透性增大,本不能滤过到肾小囊腔的血细胞和蛋白质会进入肾小囊腔中,但肾小管对血细胞和蛋白质没有重吸收能力,因此这些血细胞和蛋白质就会随尿液排出而形成血尿或蛋白尿.因此,医生在检验某人的尿液时发现了较多的红细胞,可能是[③]肾小球出现病变.

故答案为:

(1)肾小囊;

(2)动脉血;原尿;

(3)重吸收;

(4)③;肾小球.

单项选择题 A1/A2型题
单项选择题

Though it is mere 1 to 3 percent of the population, the upper class possesses at least 25 percent of the nation’s wealth. This class has two segments: upper-upper and lower-upper. Basically, the upper-upper class is the "old rich"—families that have been wealthy for several generations—an aristocracy of birth and wealth. Their names are in the Social Register, a listing of acceptable members of high society. A few are known across the nation, such as the Rockefellers, Roosevelts, and Vanderbilts. Most are not visible to the general public. They live in grand seclusion, drawing their income from the investment of their inherited wealth. In contrast, the lower-upper class is the "new rich". Although they may be wealthier than some of the old rich; the new rich have hustled to make their money like everybody else beneath their class. Thus their prestige is generally lower than that of the old rich, who have not found it necessary to lift a finger to make their money, and who tend to look down upon the new rich.

However its wealth is acquired, the upper class is very, very rich. They have enough money and leisure time to cultivate an interest in the arts and to collect rare books, painting, and sculpture. They generally live in exclusive areas, belong to exclusive social clubs, communicate with each other, and marry their own kind—all of which keeps them so distant from the masses that they have been called the out-of-sight class. More than any other class, they tend to be conscious of being members of a class. They also command an enormous amount of power and influence here and a broad, as they hold many top government positions, run the Council on Foreigh Relations, and control multinational corporations. The actions affect the lives of millions.

We can learn from the passage that()

A. the upper class is powerful and influential

B. the upper class collects rare books to make money

C. the upper class holds all top government positions

D. the "old rich" makes much more money than the "new rich"