新托福考試采用真實場景，如模擬大學校園中的動態(tài)和交互式環(huán)境，試題綜合考查聽、說、讀、寫4項英語語言能力，考生可充分展示使用英語進行交流的能力。只有在自己充分準備好了之后才會一舉攻破托?？荚嚧箨P(guān)，今天出國留學網(wǎng)為大家?guī)硗懈ｉ喿x背景知識之肺部有味覺，希望能幫助到大家!
【托福閱讀背景知識之肺部有味覺】
Take a deep breath. Taste anything? Actually, your lungs may. Because scientists have discovered that the same receptors that exist on the tongue to taste bitter substances are also found on the smooth muscle of the lungs.
Researchers were studying the receptors on smooth lung muscles that regulate contraction and relaxation of theairways. That’s when they made the discovery—which was so unexpected that the researchers themselves were skeptical.
Finally, they became convinced that the receptors were really there, though not clustered in taste buds as they are on the tongue. The scientists then exposed human and mouse airways to various bitter compounds to gauge the effects.
Many toxic compounds are bitter, so the researchers expected the lung muscle to tense up and contract—to compel the breather to move away from whatever was bitter and perhaps toxic. But, in a second surprise, bitter compounds relaxed and opened airways better than any existing asthma drug. The study is in the journal Nature Medicine. "Bitter taste receptors on airway smooth muscle bronchodilate by localized calcium signaling and reverse obstruction".
Researchers will continue to search for the role of the receptors. Meanwhile, the work represents a surprising new lead in the search for drugs to treat asthma, emphysema or chronic bronchitis.—Cynthia Graber
希望以上由出國留學網(wǎng)為大家?guī)淼耐懈ｉ喿x背景知識之肺部有味覺，希望能給大家提供幫助!出國留學網(wǎng)及時為大家提供最新留學資訊，大家可按Ctrl+D收藏本站，即可第一時間了解更多托福考試資訊!
>>>點擊進入出國留學網(wǎng)托?？荚嚈谀苛私飧?/strong>
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