SSS 2008-03-11
时间：2019-01-08 作者：英语课 分类：Scientific American(三)月
This is Scientific American’s 60-Second Science. I’m Karen Hopkin, this will just take a minute.
Anyone who’s ever cut up an onion knows that some smells can actually be painful. Now, researchers from Baltimore and Denver are closer to understanding why. Scientists used to think that odors that are irritating like onions and ammonia directly activate 1 the trigeminal nerve. That nerve responds to touch, temperature and painful stimulation 2 all over the head. And its fibers 3 extend to the membranes 4 that line the inside of the nose. But the current studies suggest that the trigeminal nerve doesn’t act alone. Specialized 5 chemosensory cells that line the nasal cavity are actually the first to detect irritating smells. They pass the news to the trigeminal nerve, which then lets your brain know that it’s time to feel the burn and to tear, or cough or gag,or just generally back off. The findings are described in the March issue of the Journal of Neurophysiology. Having these special sensory 6 cells as a go-between, the scientists say, might make our nose sensitive to a broader variety of odors, that may not seem like such a bonus. But the system probably evolved to protect us, by giving us a heads-up when we run into something nauseous. It may also keep us from adding too many onions to the spaghetti sauce.
Thanks for the minute. For Scientific American’s 60-Second Science. I’m Karen Hopkin
- We must activate the youth to study.我们要激励青年去学习。
- These push buttons can activate the elevator.这些按钮能启动电梯。
- The playgroup provides plenty of stimulation for the children.幼儿游戏组给孩子很多启发。
- You don't get any intellectual stimulation in this job.你不能从这份工作中获得任何智力启发。
- Thesolution of collagen-PVA was wet spined with the sodium sulfate as coagulant and collagen-PVA composite fibers were prepared. 在此基础上，以硫酸钠为凝固剂，对胶原-PVA共混溶液进行湿法纺丝，制备了胶原-PVA复合纤维。
- Sympathetic fibers are distributed to all regions of the heart. 交感神经纤维分布于心脏的所有部分。
- 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
- There are many specialized agencies in the United Nations.联合国有许多专门机构。
- These tools are very specialized.这些是专用工具。