首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
We sometimes think humans are uniquely vulnerable to anxiety, but stress seems to affect the immune defenses of lower animals to
We sometimes think humans are uniquely vulnerable to anxiety, but stress seems to affect the immune defenses of lower animals to
admin
2010-01-07
51
问题
We sometimes think humans are uniquely vulnerable to anxiety, but stress seems to affect the immune defenses of lower animals too. In one experiment, for example, behavioral immunologist Mark Laudenslager, at the University of Denver, gave mild electric shocks to 24 rats. Half the animals could switch off the current by turning a wheel in their enclosure, while the other half could not. The rats in the two groups were paired so that each time one rat turned the wheel it protected both itself and its helpless partner from the shock. Laudenslager found that the immune response was depressed below normal in the helpless rats but not in those that could turn off the electricity. What he has demonstrated, he believes, is that lack of control over an event, not the experience itself, is what weakens the immune system.
Other researchers agree. Jay Weiss, a psychologist at Duke University School of Medicine, has shown that animals who are allowed to control unpleasant stimuli don’ t develop sleep disturbances or changes in brain chemistry typical of stressed rats. But if the animals are confronted with situations they have no control over, they later behave passively when faced with experiences they can control. Such findings reinforce psychologists’ suspicions that the experience or perception of helplessness is one of the most harmful factors in depression.
One of the most startling examples of how the mind can alter the immune response was discovered by chance. In 1975 psychologist Robert Ader at the University of Rochester School of Medicine conditioned mice to avoid saccharin by simultaneously feeding them the sweetener and injecting them with a drug that while suppressing their immune systems caused stomach upsets. Associating the saccharin with the stomach pains, the mice quickly learned to avoid the sweetener. In order to extinguish this dislike for the sweetener, Ader re-exposed the animals to saccharin, this time without the drug, and was astonished to find that those mice that had received the highest amounts of sweetener during their earlier conditioning died. He could only speculate that he had so successfully conditioned the rats that saccharin alone now served to weaken their immune systems enough to kill them.
It can be concluded from the passage that the immune systems of animals ______ .
见文章第三段最后一句。
选项
A、can be weakened by conditioning
B、can be suppressed by drug injections
C、can be affected by frequent doses of saccharin
D、can be altered by electric shocks
答案
解析
A
转载请注明原文地址:https://kaotiyun.com/show/ISPd777K
本试题收录于:
公共英语四级笔试题库公共英语(PETS)分类
0
公共英语四级笔试
公共英语(PETS)
相关试题推荐
Forthefirsttime,scientistshaveprofiledspecificgeneticchangesduringtheagingofexperimentalanimals,adiscoverythat
Earthquakescanbedevastating【1】disasters.TheinfamousSanFranciscoearthquakeof1906causedover$200millionworthofdam
Earthquakescanbedevastating【1】disasters.TheinfamousSanFranciscoearthquakeof1906causedover$200millionworthofdam
Earthquakescanbedevastating【1】disasters.TheinfamousSanFranciscoearthquakeof1906causedover$200millionworthofdam
Oursocialdevelopmentwasencouragedthroughteamwork.Weworkedingroupswithpeoplewe’dnevermet【1】.Welearnttolistent
WhyisGriffithoftencalledTheFatheroftheMotionPicture?
Humanrelationshavecommandedpeople’sattentionfromearlytimes.Thewaysofpeoplehavebeenrecordedininnumerablemyths,
Humanrelationshavecommandedpeople’sattentionfromearlytimes.Thewaysofpeoplehavebeenrecordedininnumerablemyths,
Theaveragepersonseestensofthousandsofimagesaday—imagesontelevision,innewspapersandmagazines,andonthesidesof
Itwasamomentmostbusinessexecutiveswouldpausetosavor:latelastyear,GermansportinggoodspioneerAdidaslearnedthat
随机试题
纯C++程序中,如果要求通过函数来实现一种简单的功能,并且要求尽可能加快程序执行速度,则应该选用()。
1971年《伯尔尼公约》修订时增加了对发展中国家的特殊规定,其主要内容是允许发展中国家对翻译专有权和复制专有权实行()
双侧呼吸运动减弱见于()
全球气候变暖的主要原因是()
甲公司依据生效判决书向人民法院申请执行乙公司应支付的货款100万元。在执行程序中,甲公司发现乙公司虽然无财产可供执行,但是对丙公司享有90万元的到期债权。下列哪些做法是正确的?()
检察官有下列情形,应当依法提请免除其职务:
某电力用户设有110/10kV变电站一座和若干10kV车间变电所,用户所处海拔高度1500m,其供电系统图和已知条件如下图。1)110kV线路电源侧短路容量为2000MV.A。2)110kV线路电源电抗值为0.4Ω/km。3
家庭成熟期的收入与支出表现为()。
以太网中,当数据传输率提高时,帧的发送时间就会相应地缩短,这样可能会影响到>中突的检测。为了能有效地检测冲突,可以使用的解决方案有()。
在考生文件夹下COMP文件夹中建立一个新文件夹COAL。
最新回复
(
0
)