环球英语 — 207：Body Clock

　　Voice 1
Thank you for joining us for today’s Spotlight¹. I’m Rebekah Schipper.
Voice 2
And I’m Joshua Leo.
Voice 1
Do you ever think about time? What is it? You cannot touch it, smell it or taste it. But you cannot escape it. Time is all around us. We organize our day by what time it is. We wake from sleep in the morning at a particular time. We go to bed at another time. We work, we eat, we play; all because of time. But why? What if there was no time? Could we exist without time?
Voice 2
Today’s Spotlight is on our body’s natural clock. Many people believe that our bodies keep their own time. So, do we really need clocks? Do we really need time?
Voice 1
Do you ever feel like your body wakes from sleep at a particular time each morning? Do you feel hungry for food at about the same time each day? Are you usually ready to go to bed at the same time each night? Have you experienced a repeating pattern with your body?
Voice 2
Research shows that people’s bodies have their own rhythms. These rhythms help people know when to get up in the morning. They help people to know when to eat. These rhythms help people know when to go to bed. Scientists believe that body rhythms repeat every twenty–four hours and eleven minutes, almost the same length as a day!
Voice 1
So, how does the body’s clock work? Well, in your brain there is a small organ called the suprachiasmatic nucleus², or the SCN. The SCN controls the body’s clock. It commands other organs and systems in the body. It causes everything to work together to tell your body what time it is. For example, in the morning your blood pressure rises. This helps you to be able to physically³ get out of bed.
Voice 2
And, in the afternoon and evening your liver produces special enzymes⁴, or chemicals. These enzymes make you feel hungry for food at a particular time.
Voice 1
Then, at night, a gland⁵ in the bottom part of your brain starts to work. The SCN causes the gland to produce another kind of chemical called melatonin. Melatonin makes you feel tired. As you sleep, the temperature in your body drops. In the morning the sun comes up. The light hits your eyes. This stops your body from producing melatonin. Soon you feel ready to get out of bed! The SCN organ makes sure that this pattern repeats day after day.
Voice 2
In 1962, a scientist named Michel Siffre discovered the body’s natural clock. Michel wanted to study the movement of an ice glacier⁶. He went into an underground cave to find the glacier. But while he was in the cave he had an idea. Michel said,
Voice 3
“I had the idea of my life. I decided⁷ not to take a (clock) in the cave. I decided to live without time (signals).”
Voice 2
In the cave Michel was away from day light, clocks, and routines, or day time patterns. He hoped to discover if the body had its own rhythm. Michel said,
Voice 3
“I decided to live following my feelings of hunger, my feelings of going to sleep. In the cave it is always dark. (So) your body has to follow its own sense.”
Voice 1
Each day Michel would call his team members. They were working above ground. Michel would call them every time he woke from sleep. He would call them every time he ate, exercised, and even when he expelled waste from his body. Michel would then tell his team what time he thought it was. But, he really had no idea! His team wrote down the time of each of Michel’s body behaviours. Then they compared Michel’s estimated time with the real time. They did this for two months.
Voice 2
So, was Michel able to know what time it was just by following his body’s natural ways? Well, the results showed that Michel followed a clear repeating pattern each day. The scientists measured Michel’s days from the time he woke from sleep in the morning to the time he woke from sleep the next morning. They found the average length of Michel’s days in the cave. They were just over twenty–four hours! That was very close to the Earth’s natural day length! So, it seems that our bodies have a natural twenty–four hour rhythm.
Voice 1
Many people have body clocks that run close to a twenty–four hour day. But not everybody’s body clocks are the same. Some people have extremely different body clocks! For example, members of the McQuerry family in the United States have very different daily patterns. Mr. McQuerry and his daughter rise from sleep every day at four in the morning. They cannot stop this from happening. Their bodies naturally wake up! The daughter works on her school work. The father goes to the store to buy the family’s food. These two McQuerry’s are extremely tired very early in the night. They feel like they must sleep.
Voice 2
But Mrs. McQuerry and her son have different body clocks. They sleep until late in the morning. They stay up late at night. The McQuerry family sometimes wishes that their body clocks were the same. They wish they could have more time to spend together.
Voice 1
The McQuerry family’s situation is rare. The father and daughter suffer from Advanced Sleep Phase Syndrome⁸, or ASPS. It is a disease of the body’s natural clock. Mr. McQuerry and his daughter’s body clocks are pushed forward. That makes them feel tired much earlier than most people. And it makes them rise very early in the morning. But the McQuerrys have learned about ASPS. They try to work around their different body clocks. They try to spend more time together.
Voice 2
The body’s natural clock is important, no matter what time you like to do things. The body clock is important for health. Several studies suggest that obeying your body’s clock can help reduce tiredness. And people who get at least seven hours of sleep are much less likely to be obese⁹, or over a normal weight. Going to bed and getting up at the same time every day also keeps your body’s clock on schedule. Your body’s clock controls your body’s temperature, hormones¹⁰, blood pressure and other important body systems. Changing your body’s pattern can cause serious health problems. So, be sure to listen to your body. Keeping to your body’s clock can keep you healthy!
Voice 1
Thank God for our body’s natural clock. It is just another small way that God cares for his most wonderful creation – us!
 

1 spotlight   

n.公众注意的中心，聚光灯，探照灯，视听，注意，醒目

参考例句：

• This week the spotlight is on the world of fashion.本周引人瞩目的是时装界。
• The spotlight followed her round the stage.聚光灯的光圈随着她在舞台上转。

2 nucleus   

n.核，核心，原子核

参考例句：

• These young people formed the nucleus of the club.这些年轻人成了俱乐部的核心。
• These councils would form the nucleus of a future regime.这些委员会将成为一个未来政权的核心。

3 physically   

adj.物质上，体格上，身体上，按自然规律

参考例句：

• He was out of sorts physically,as well as disordered mentally.他浑身不舒服，心绪也很乱。
• Every time I think about it I feel physically sick.一想起那件事我就感到极恶心。

4 enzymes   

n. 酶，酵素

参考例句：

• It was said that washing powders containing enzymes remove stains more efficiently. 据说加酶洗衣粉除污更有效。
• Among the enzymes which are particularly effective are pepsin, papain. 在酶当中特别有效的是胃朊酶、木瓜酶。

5 gland   

n.腺体，(机)密封压盖，填料盖

参考例句：

• This is a snake's poison gland.这就是蛇的毒腺。
• Her mother has an underactive adrenal gland.她的母亲肾上腺机能不全。

6 glacier   

n.冰川，冰河

参考例句：

• The glacier calved a large iceberg.冰河崩解而形成一个大冰山。
• The upper surface of glacier is riven by crevasses.冰川的上表面已裂成冰隙。

7 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

8 syndrome   

n.综合病症；并存特性

参考例句：

• The Institute says that an unidentified virus is to blame for the syndrome. 该研究所表示,引起这种综合症的是一种尚未确认的病毒。
• Results indicated that 11 fetuses had Down syndrome. 结果表明有11个胎儿患有唐氏综合征。

9 obese   

adj.过度肥胖的，肥大的

参考例句：

• The old man is really obese,it can't be healthy.那位老人确实过于肥胖了，不能算是健康。
• Being obese and lazy is dangerous to health.又胖又懒危害健康。

10 hormones   

n. 荷尔蒙，激素 名词hormone的复数形式

参考例句：

• This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
• The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。