英语听力文摘 English Digest 63、啤酒对大脑的影响

　　Under normal circumstances, each of your brain cells allows various substances, such as sodium¹, calcium² and potassium to permeate³ its outer cell membrane⁴.
Once inside the brain cell, these substances help give the cell stimulus⁵ it needs to function properly. Then they leave the cell and allow another set of these substances to begin the cycle again.
The millions of cells that make up your brain are continually allowing these substances to penetrate⁶ their membranes⁷ and then expelling these same substances later. All of this action allows the brain to interpret and transport messages.
Alcohol consumption prevents sodium from being able to cross brain cell membranes. Once even this part of the cycle breaks down, brain functions become impaired⁸.
You can notice the affects of this break down after a single drink. Even if you’ve had just one drink, your ability to respond to stimulus decreases and your reaction time slows down.
If you’re driving, you might see a car stop, and know that you need to slam on the brakes, but the pathway in your brain that processes this information and causes you to respond to it will be working in slow motion.
sodium:钠
calcium:钙
potassium:钾
cell membrane:细胞膜
slam:猛烈抨击;使劲一推

1 sodium   

n.（化）钠

参考例句：

• Out over the town the sodium lights were lit.在外面，全城的钠光灯都亮了。
• Common salt is a compound of sodium and chlorine.食盐是钠和氯的复合物。

2 calcium   

n.钙(化学符号Ca)

参考例句：

• We need calcium to make bones.我们需要钙来壮骨。
• Calcium is found most abundantly in milk.奶含钙最丰富。

3 permeate   

v.弥漫，遍布，散布；渗入，渗透

参考例句：

• Water will easily permeate a cotton dress.水很容易渗透棉布衣服。
• After a while it begins to permeate through your skin.过了一会，它会开始渗入你的皮肤。

4 membrane   

n.薄膜，膜皮，羊皮纸

参考例句：

• A vibrating membrane in the ear helps to convey sounds to the brain.耳膜的振动帮助声音传送到大脑。
• A plastic membrane serves as selective diffusion barrier.一层塑料薄膜起着选择性渗透屏障的作用。

5 stimulus   

n.刺激，刺激物，促进因素，引起兴奋的事物

参考例句：

• Regard each failure as a stimulus to further efforts.把每次失利看成对进一步努力的激励。
• Light is a stimulus to growth in plants.光是促进植物生长的一个因素。

6 penetrate   

v.透(渗)入；刺入，刺穿；洞察，了解

参考例句：

• Western ideas penetrate slowly through the East.西方观念逐渐传入东方。
• The sunshine could not penetrate where the trees were thickest.阳光不能透入树木最浓密的地方。

7 membranes   

n.（动物或植物体内的）薄膜( membrane的名词复数 )；隔膜；（可起防水、防风等作用的）膜状物

参考例句：

• The waste material is placed in cells with permeable membranes. 废液置于有渗透膜的槽中。 来自辞典例句
• The sarcoplasmic reticulum is a system of intracellular membranes. 肌浆网属于细胞内膜系统。 来自辞典例句

8 impaired   

adj.受损的；出毛病的；有（身体或智力）缺陷的v.损害，削弱( impair的过去式和过去分词 )

参考例句：

• Much reading has impaired his vision. 大量读书损害了他的视力。 来自《现代汉英综合大词典》
• His hearing is somewhat impaired. 他的听觉已受到一定程度的损害。 来自《现代汉英综合大词典》