托福阅读背景资料：味觉系统调查

 　　托福阅读文章分为自然科学、人文科学、互联网等几大类，如果同学们平时能对这些种类的文章都有所涉猎，托福阅读考试中遇到相关的话题就会有非常熟悉的感觉。下面给大家提供一篇关于人类味觉系统的背景材料，希望能拓宽同学们的阅读面。

　　Take a deep breath. Taste anything? Actually，your lungs may. Because scientists have discoveredthat the same receptors that exist on the tongue totaste bitter substances are also found on thesmooth muscle of the lungs.

　　Researchers were studying the receptors on smooth lung muscles that regulatecontraction and relaxation¹ of theairways. That’s when they made the discovery—which was sounexpected that the researchers themselves were skeptical⁴.

　　Finally， they became convinced that the receptors were really there， though notclustered in taste buds as they are on the tongue. The scientists then exposed human andmouse airways³ to various bitter compounds to gauge⁵ the effects.

　　Many toxic⁶ compounds are bitter，so the researchers expected the lung muscle to tense upand contract—to compel the breather to move away from whatever was bitter and perhapstoxic. But， in a second surprise， bitter compounds relaxed and opened airways better thanany existing asthma⁷ drug. The study is in the journal Nature Medicine. [Deepak Deshpande etal.， “Bitter taste receptors on airway² smooth muscle bronchodilate by localized calciumsignaling and reverse obstruction”]

　　Researchers will continue to search for the role of the receptors. Meanwhile， the workrepresents a surprising new lead in the search for drugs to treat asthma， emphysema orchronic bronchitis.

　　—Cynthia Graber

 

1 relaxation   

n.松弛，放松；休息；消遣；娱乐

参考例句：

• The minister has consistently opposed any relaxation in the law.部长一向反对法律上的任何放宽。
• She listens to classical music for relaxation.她听古典音乐放松。

2 airway   

n.空中航线，通风口

参考例句：

• Lay them on their side and ensure the airway is unobstructed.让他们侧躺着，并确保呼吸道畅通。
• There is a purple airway in London Airport.伦敦机场里有一条皇家专用飞机跑道。

3 AIRWAYS   

航空公司

参考例句：

• The giant jets that increasingly dominate the world's airways. 越来越称雄于世界航线的巨型喷气机。
• At one point the company bought from Nippon Airways a 727 jet. 有一次公司从日本航空公司买了一架727型喷气机。

4 skeptical   

adj.怀疑的，多疑的

参考例句：

• Others here are more skeptical about the chances for justice being done.这里的其他人更为怀疑正义能否得到伸张。
• Her look was skeptical and resigned.她的表情是将信将疑而又无可奈何。

5 gauge   

v.精确计量；估计；n.标准度量；计量器

参考例句：

• Can you gauge what her reaction is likely to be?你能揣测她的反应可能是什么吗？
• It's difficult to gauge one's character.要判断一个人的品格是很困难的。

6 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

7 asthma   

n.气喘病，哮喘病

参考例句：

• I think he's having an asthma attack.我想他现在是哮喘病发作了。
• Its presence in allergic asthma is well known.它在过敏性气喘中的存在是大家很熟悉的。