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
71
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.
Laudenslager’ s experiment showed that the immune system of those rats who could turn off the electricity ______ .
见文章第一段倒数第二句。
选项
A、was strengthened
B、was not affected
C、was altered
D、was weakened
答案
解析
B
转载请注明原文地址:https://kaotiyun.com/show/9SPd777K
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
Therearetwobasicwaystoseegrowth:oneasaproduct,theotherasaprocess.Peoplehavegenerallyviewedpersonalgrowtha
Whatnaturalresourcesdidthesouthernparthave?
Whatnaturalresourcesdidthesouthernparthave?
Everyoneagreesonhowtelevisionaffectsviewers.
Achildwhohasoncebeenpleasedwithatalelikes,asarule,tohaveitretoldinidenticallythesamewords,butthisshould
Earthquakescanbedevastating【1】disasters.TheinfamousSanFranciscoearthquakeof1906causedover$200millionworthofdam
Earthquakescanbedevastating【1】disasters.TheinfamousSanFranciscoearthquakeof1906causedover$200millionworthofdam
Earthquakescanbedevastating【1】disasters.TheinfamousSanFranciscoearthquakeof1906causedover$200millionworthofdam
Oursocialdevelopmentwasencouragedthroughteamwork.Weworkedingroupswithpeoplewe’dnevermet【1】.Welearnttolistent
Thelimitedtimeandspacewhichmanoccupiessuggest,accordingtotheparagraph,Expertssuchastheso-calledinsiders
随机试题
已知焊件厚度为14mm,采用I形坡口双面埋弧焊。焊接参数为:焊接电流为600A,电弧电压为34V,焊接速度为27m/h,求焊接热输入。
当身体因营养不良,而出现牙齿萌出迟缓,牙体发育不良、乳牙滞留的常说明存在呼吸功能异常、睡眠时张口呼吸,舌及下颌后退,会形成
痰饮停胃,则可见
某市甲县工商局认定某机电公司从乙县贸易公司购进的3辆进口汽车的准运证系伪造,作出没收3辆汽车和罚款20万元的处罚决定。县机电公司不服,向市工商局申请复议。市工商局认为县工商局的处罚过重,遂作出没收3辆汽车但不罚款的复议决定。机电公司仍不服,向法院起诉。下列
公路建设市场信用信息包括公路建设从业单位的()。
一般资料:求助者,男性,32岁,未婚,律师。案例介绍:求助者去年底代理过一起伤害致死案件,受害者在购物时与他人争打后突然死亡,经法医鉴定为情绪激动引发心脏病所致。求助者查阅资料后得知,身强力壮的年轻人也可因突发心脏病死亡。某日乘公共汽车,人多拥挤,
A.Wushuschoolshavedevelopedquickly.B.Itcanstrengthenphysicalhealth.C.Wushuhasaverydeepbasefromthemasses.A:
在C++中,打开一个文件时与该文件建立联系的是()。
Shynessisthecauseofmuchunhappinessforagreatmanypeople.Shypeopleareanxiousand(36)______;thatis,theyareexces
Tounderstandthemarketingconcept,itisonlynecessarytounderstandthedifferencebetweenmarketingandselling.Nottooma
最新回复
(
0
)