VOA慢速英语-Health Report - How the Heart Works

Some facts about an extraordinary organ, and the threats it faces. Transcript¹ of radio broadcast:
29 July 2008

This is the VOA Special English Health Report.

We talked last week about the life of famed heart doctor Michael DeBakey. He died this month at age ninety-nine.

Today, we talk about the object of his work. The heart is a complex organ that starts beating a few weeks after conception². At this point the heart is a tube. In the coming days, it grows and bends into the shape of the heart.
　

Doctor Craig Smith uses a model to explain the heart operation he performed on former president Bill Clinton in September 2004

Later, it divides into four parts. As the heart beats, it pumps blood through these chambers³ and the blood vessels⁴ in the body. The body is estimated to have at least ninety-six thousand kilometers of blood vessels.

That is about the same as two and a half times around the Earth. But blood goes the distance in about twenty seconds on its way back to the heart. Each day the heart pumps about eight thousand liters of blood.

The blood feeds the brain and other organs with oxygen and nutrients⁵. It also carries away carbon dioxide and other waste.

The heart pumps by expanding and contracting of muscle. In a healthy adult, the heart beats an average of seventy-two times a minute -- about one hundred thousand times a day.

A healthy adult heart is about the size of two fists and looks like a piece of red meat. But in overweight people, it can look yellow because of fat.

Rates of heart disease started growing sharply⁶ in the second half of the twentieth century. As machines did more and more work, people did less and less. Not only did physical activity decrease, but people started eating more and more processed foods.

Experts say a diet low in fats and high in fruits, vegetables, proteins and whole grains may help reduce the risk of heart disease. At least thirty minutes a day of physical activity, enough to work up a sweat, can also help. Also important to good health is a good night's sleep.

Cardiovascular disease is caused by disorders⁷ of the heart and blood vessels. It includes heart attacks, strokes and high blood pressure. The World Health Organization says there are three major causes: tobacco use, physical inactivity and an unhealthy diet.

The W.H.O. says cardiovascular disease is the world's leading cause of death. And it is predicted to remain that way unless more action is taken. Experts estimate that it could kill twenty million people a year by twenty fifteen. An estimated seventeen and a half million people died in the year two thousand five. Around eighty percent of them died in low- and middle-income countries.

And that's the VOA Special English Health Report, written by Caty Weaver⁸. For more health news, go to voaspecialenglish.com. I'm Steve Ember.

1 transcript   

n.抄本，誊本，副本，肄业证书

参考例句：

• A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
• They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。

2 conception   

n.思想，观念，概念，构想，设想，怀孕

参考例句：

• He's got a pretty strange conception of friendship.他对友谊有一种非常独特的见解。
• A good novelist needs great power of conception.一个好的小说家需要丰富的想象力。

3 chambers   

n.房间( chamber的名词复数 )；（议会的）议院；卧室；会议厅

参考例句：

• The body will be removed into one of the cold storage chambers. 尸体将被移到一个冷冻间里。 来自《简明英汉词典》
• Mr Chambers's readable book concentrates on the middle passage: the time Ransome spent in Russia. Chambers先生的这本值得一看的书重点在中间：Ransome在俄国的那几年。 来自互联网

4 vessels   

n.血管( vessel的名词复数 )；船；容器；（具有特殊品质或接受特殊品质的）人

参考例句：

• The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
• All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》

5 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》

6 sharply   

adj.锐利地，急速；adv.严厉地，鲜明地

参考例句：

• The plane dived sharply and rose again.飞机猛然俯冲而后又拉了起来。
• Demand for personal computers has risen sharply.对个人电脑的需求急剧增长。

7 disorders   

n.混乱( disorder的名词复数 )；凌乱；骚乱；（身心、机能）失调

参考例句：

• Reports of anorexia and other eating disorders are on the increase. 据报告，厌食症和其他饮食方面的功能紊乱发生率正在不断增长。 来自《简明英汉词典》
• The announcement led to violent civil disorders. 这项宣布引起剧烈的骚乱。 来自《简明英汉词典》

8 weaver   

n.织布工；编织者

参考例句：

• She was a fast weaver and the cloth was very good.她织布织得很快，而且布的质量很好。
• The eager weaver did not notice my confusion.热心的纺织工人没有注意到我的狼狈相。