问题 单项选择题 A1型题

休克早期的代偿反应中,错误的是()

A.心跳加快,心排血量增加

B.皮肤血管收缩

C.骨骼肌血管收缩

D.内脏血管扩张

E.毛细血管网关闭

答案

参考答案:D

解析:

休克早期,起初可通过加强心肌收缩,增强心排出量以代偿,同时藉收缩腹腔内脏、皮肤、骨骼肌血管,使血液重新分配,以保证心、脑重要器官的灌注。此时体内大部分的微循环小血管包括微动脉、后微动脉、毛细血管前括约肌和微静脉均持续收缩,尤以毛细血管前括约肌收缩明显,因此,毛细血管前阻力显著升高致毛细血管网关闭、微循环血流量明显减少。同时许多位于微动脉和微静脉之间的直捷通路和动静脉短路开放,因此,使组织的缺血、缺氧情况更为加重。此时称为微循环缺血期,是休克代偿期的微循环变化。

单项选择题

There are many kinds of friends. Some are always (1) you, but don’t understand you. Some say only a few words to you, but understand you. Many people will step in your life, but only (2) friends leave footprints.

I shall always recall the autumn and the girl with the (3) . She will always bring back the friendship between us. I know she will always be my best friend.

It was the golden season. I could see the yellow leaves (4) with the cool (5) . In such a season, I liked walking alone on the roads covered with leaves, (6) to the sound of them.

Autumn is a (7) season and life is uninteresting. The free clays always get me (8) . But one day, the sound of a violin (9) into my ears like a stream flowing in them ountains. I was so surprised that I jumped to see what it was. A young girl, standing in the wind, was (10) in playing her violin.

I had (11) seen her before. The music was so nice that I listened quietly. Lost in the music, I didn’t know that I had been (12) there for so long but my existence did not seem to disturb her.

Leaves were still falling. Every day she played the violin at the comer of the building (13) I went downstairs to watch her performance. I was the only listener. The autumn seemed no longer lonely and life became (14) . (15) we didn’t know each other, I thought we were already good friends. I believe she also loved me.

Autumn was nearly over. One day, when I was listening carefully, the sound suddenly (16) . To my astonishment, the girl came over to me.

"You must like music from the violin. " she said.

"Yes. And you play very well. Why did you stop" I asked.

Suddenly, a (17) expression appeared on her face and I could feel something unusual.

"I came here to see my grandmother, but now I must leave. I once played very badly. It was your listening every day that (18) me." she said.

"In fact, it was your playing (19) gave me a meaningful autumn," I answered, "Let’s be friends. "

The girl smiled, and so did I. I never heard her play again in my life. I no longer went downstairs to listen to her. Only thick leaves were left behind. But I will always remember the fine figure of the girl. She is like a (20) —so short, so bright, like a shooting star giving off so much light that makes the autumn beautiful.

15().

A.But

B.However

C.Even

D.Though

填空题