问题 单项选择题

关于心力衰竭时各种体液因子的改变,下列那项正确

A.心衰时,缓激肽生成增加
B.缓激肽有很强的利尿作用
C.心衰早期,心钠素分泌减少
D.内皮依赖性释放因子有强大的缩血管作用
E.由于心排血量降低,引起血管加压素分泌减少

答案

参考答案:A

解析:[解释] 心力衰竭时,RAS系统激活,缓激肽生成增多。血管内皮细胞在缓激肽的刺激下产生内皮依赖性释放因子(NO),该因子有强大的扩血管作用而不是缩血管作用。心衰时,心房内压力增高,促使心房肽(心钠素)分泌增加。心房肽具有很强的利尿作用,而不是缓激肽。由于心衰时心排出量下降,反射性促使血管加压素分泌增加,起到缩血管、抗利尿、增加血容量作。

阅读理解

We’ve reached a strange—some would say unusual—point. While fighting world hunger continues to be the matter of vital importance according to a recent report from the World Health Organization (WHO), more people now die from being overweight, or say, from being extremely fat, than from being underweight. It’s the good life that’s more likely to kill us these days.

Worse, nearly l8 million children under the age of five around the world are estimated to be overweight. What’s going on?

We really don’t have many excuses for our weight problems. The dangers of the problem have been drilled into us by public-health campaigns since 2001 and the message is getting through—up to a point.

In the 1970s, Finland, for example, had the highest rate of heart disease in the world and being overweight was its main cause. Not any more. A public-health campaign has greatly reduced the number of heart disease deaths by 80 per cent over the past three decades.

Maybe that explains why the percentage of people in Finland taking diet pills doubled between 2001 and 2005, and doctors even offer surgery of removing fat inside and change the shape of the body. That has become a sort of fashion. No wonder it ranks as the world’s most body-conscious country.

We know what we should be doing to lose weight—but actually doing it is another matter. By far the most popular excuse is not taking enough exercise. More than half of us admit we lack willpower.

Others blame good food. They say: it’s just too inviting and it makes them overeat. Still others lay the blame on the Americans, complaining that pounds have piled on thanks to eating too much American-style fast food.

Some also blame their parents—their genes. But unfortunately, the parents are wronged because they’re normal in shape, or rather slim.

It’s a similar story around the world, although people are relatively unlikely to have tried to lose weight. Parents are eager to see their kids shape up. Do as I say—not as I do.

小题1:What is the “strange” point mentioned in the first sentence?

A.The good life is a greater risk than the bad life.

B.Starvation is taking more people’s lives in the world.

C.WHO report shows people’s unawareness of food safety.

D.Overweight issue remains unresolved despite WHO’s efforts.小题2:Why does the author think that people have no excuse for being overweight?

A.A lot of effective diet pills are available.

B.Body image has nothing to do with good food.

C.They have been made fully aware of its dangers.

D.There are too many overweight people in the world.小题3:The example of Finland is used to illustrate ______.

A.the cause of heart disease

B.the fashion of body shaping

C.the effectiveness of a campaign

D.the history of a body-conscious country小题4:Which would be the best title for the passage?

A.Actions or Excuses?

B.Overweight or Underweight?

C.WHO in a Dilemma

D.No Longer Dying of Hunger

判断题