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
38
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
AlthoughsocialchangesintheUnitedStateswerebeingwroughtthroughoutmostofthenineteenthcentury,publicawarenessoft
Everyoneagreesonhowtelevisionaffectsviewers.
Oursocialdevelopmentwasencouragedthroughteamwork.Weworkedingroupswithpeoplewe’dnevermet【1】.Welearnttolistent
Largecompaniesneedawaytoreachthesavingsofthepublicatlarge.Thesameproblem,onasmallerscale,facespractically
Largecompaniesneedawaytoreachthesavingsofthepublicatlarge.Thesameproblem,onasmallerscale,facespractically
Aneweraisuponus.Callitwhatyouwill:theserviceeconomy,theinformationage,theknowledgesociety.Italltranslates
IfyouarebuyingapropertyinFrance,whetherforapermanentoraholidayhome,itisimportanttoopenaFrenchbankaccount
Periodicallyinhistory,therecomeperiodsofgreattransitioninwhichworkchangesitsmeaning.Therewasatime,perhaps10,
Itwasamomentmostbusinessexecutiveswouldpausetosavor:latelastyear,GermansportinggoodspioneerAdidaslearnedthat
HowdoesAusubelfeelaboutthescientificprogressmadeeveryday?
随机试题
试述政策创新与政策变动、政策终结、政策接续相比的不同之处。
骨髓增生极度活跃或明显活跃,骨髓中原始粒细胞占30%~89%(NEC),并可见到早幼粒细胞、中幼粒细胞和成熟粒细胞>10%,约50%病例的白血病细胞内可见到Auer小体。该白血病的原始细胞与急性淋巴细胞白血病原始细胞鉴别可观察
皮脂腺的特征,哪项是错误的()。
钉洞固位型一般不设在
工程量清单的项目编码以五级编码设置,一共用()位阿拉伯数字来表示。
我某进口公司按FOB条件进口一批货物,采用程租船运输,如果我方不愿承担装船费用,应采用()。
下列()基差之变化,称为基差走强。
①它的颜色是灰的,不是白色;它的重量像是雨点,并不会飞舞②去年在福建,仿佛比现在更迟一点,也曾见过雪③但那是远处山顶的积雪,可不是飞舞的雪花④一到地面,它立刻融成了水,没有痕迹,也未尝跳跃,也未尝发出唏嘘的声音,像江浙一带下雪
ThereisgrowinginterestinEastJapanRailwayCo.ltd.,oneofthesixcompanies,createdoutoftheprivatizednationalrailw
Whatdoesthepassagesayabouttheeatingbehaviorofsharks?
最新回复
(
0
)