问题 单项选择题

美国科学家声称,每人生来有两个脑,即颅脑与肠脑。肠脑位于食管、胃脏、小肠与结肠内层组织的鞘中,含有神经细胞、神经传递质、蛋白质和复杂的环行线路。结肠炎、过敏性肠炎综合症等都与肠脑内产生的问题有关。肠脑中几乎能找到颅脑赖以运转和控制的所有物质,如血清素、多巴胺、谷氨酸、去甲肾上腺素、一氧化氮等。此外,肠脑中还存在多种被称为神经肽的脑蛋白、脑啡肽以及对神经起显著作用的化学物质。颅脑面临惊恐时释出的应激激素会冲击胃脏产生痉挛;惊恐又引起交感神经影响肠脑的血清素分泌量。应激激素过分刺激还会导致腹泻。当情绪压抑时,食管神经受到高度刺激会感到吞咽困难;颅脑释出的应激激素还会改变胃脏与食管间的神经功能,导致胃灼热。最初的脑神经系统起始于管形动物,生存竞争需要更复杂的颅脑,从而发展了中枢神经系统。重要的肠神经系统不能进入头颅与胃肠相联,而为了适应高级动物进食和消化的需要,自然法则就保存了有独立功能的肠神经系统。就人而言,早期胚胎发育中产生的神经脊,一部分进入了中枢神经系统,另一部分变成肠神经系统,通过迷走神经连接两者——颅脑和肠脑。

下列解说,符合原文意思的一项是()

A.应激激素作用于肠脑引起肠神经系统化学物质的改变

B.情绪的变化是肠脑和颅脑发生联系的重要渠道

C.进食和消化的需要是肠神经系统形成的基础条件

D.重要的肠神经系统因不能进入头颅而成为独立系统

答案

参考答案:D

阅读理解

  As we know, Human beings each have unique brains. The brain is of the greatest importance to the body. It is the boss of the body.Your eyes,ears,nose,and skin tell your brain what is going on around you.Other parts of your body tell your brain what is going on inside of you.Your brain takes in the signals.It tells your body what to do with them.When you touch fire,your skin tells your brain that your finger is too hot.Your brain tells you to move your finger.All these happen very fast.Your brain also controls your breathing,blinking,and heartbeat.It controls your feelings and thoughts too.

  Humans have the most developed brain of all animals.Yet it is not the largest brain.The human brain weighs three pounds.The brain of an elephant weighs 11 pounds.So the largest brain is not always the best brain.In people,a larger brain does not mean a clever person.

小题1:What is the main idea of this passage?

  

A.The human brain works very fast.

B.The largest brain is not always the best brain.

C.The brain controls the body.

D.The best brain is the largest brain.小题2:What happens after the brain takes in the signals from the body?

A.The brain grows faster and larger.

B.The brain tells the body what to do.

C.The body becomes more developed.

D.We don't know.小题3:What does “the boss of the body” mean?

A.The signals.

B.The most developed body part.

C.The main part of the body.

D.The centre of the body.小题4:Which brain is the most developed?

A.The largest brain.

B.The human brain.

C.The smaller brain.

D.Not too big brain.小题5:What are the things that the human brain does?

  A.Takes in signals.       B.Controls breathing.

  C.Controls feelings and thoughts. D.A,B and C.

判断题