问题 配伍题 B型题

心功能不全,周围阻力降低()。
血容量不足()。
血容量轻度不足()。

A.中心静脉压低,动脉压低

B.中心静脉压低,动脉压正常

C.中心静脉压高,动脉压低

D.中心静脉压高,动脉压正常

E.中心静脉压正常,动脉压低

答案

参考答案:E,A,B

解析:

1.在低血压时,中心静脉压低于0.49kPa(5cmH2O)时,表示血容量不足;高于1.47kPa(15cmH2O)时,则提示心功能不全、静脉血管床过度收缩或肺循环阻力增加;高于1.96kPa(20cmH2O)时,则表示有充血性心力衰竭。3.周围血管阻力降低,回心血量减少,中心静脉压可正常。5.心率增加后动脉压正常,但回心血量减少,中心静脉压降低。

单项选择题
阅读理解

阅读理解。

     It's easy to see how the sawfish got its name. These frightful creatures can grow to be more

than 6 meters long. Their bodies are flat and winged, like underwater airplanes. And their noses

are shaped like chainsaws.

     Sawfish are food hunters of the sea. When a sawfish is hungry, it waves its sharptoothed snout

(口鼻部) through a group of fish. Then, it lifts its nose and uses its mouth to draw the injured victims.

     Hardy (适应力强的) population of sawfish thrived in warm waters along coastlines around the

world for thousands of years. Over the past 200 years, however, human actions have severely

endangered sawfish. Threats include fishing nets that trap the huge animals, often by mistake.

     Some people collect sawfish's snouts as prizes: One snout recently sold for nearly $1,600 online.

In some Asian cultures, the toothy snouts are used in ceremonies to drive evil and disease away. And

sawfish are also delicious. A growing demand in Asia for the fish's fins for a pricey soup has contributed

to the fish's disappearance. Compared with other fish, sawfish give birth late in life and at slow rates,

which makes it hard for them to recover from overfishing.

     New efforts now aim to restore sawfish population. Beginning next month, an international agreement

will provide protection for all seven of the world's sawfish species. Scientists are hoping that it's not too

late to save the sawfish.

     "Until 1998, this fish had never been formally studied in the United States," says Tonya Wiley of the

Mote Marine Laboratory in Sarasota, FIA."We didn't know such basic things as where they live, what

habitat they use, how often they breed, how many young they have- even what age sawfish are when

they begin breeding."

     Through historical studies and field research, scientists have become aware of how much the fish's

numbers have decreased. Today, there may be 90 percent fewer sawfish than there used to be. Wiley

estimates that only 3,000 to 6,000 sawfish remain in US waters.

                                                                Sawfish