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
2011-01-02
46
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 immuue 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 drag 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 reexposed the animals to sac charin, 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 ______.
选项
A、was strengthened
B、was not affected
C、was altered
D、was weakened
答案
B
解析
文章第一段倒数第二句“Laudenslager found that the immune response was depressed below normal in the helpless rats but not in those that could turn off the electricity.”明确说明切断不了电流的老鼠(无助的老鼠)免疫功能被削弱,而能够切断电流的老鼠则不受影响,所以[B)是正确答案。
转载请注明原文地址:https://kaotiyun.com/show/xEeO777K
0
专业英语八级
相关试题推荐
SevenTypesofEvidenceItisimportanttolearntouseevidenceinargumentativewriting,becausewithoutevidence,youcan’
SevenTypesofEvidenceItisimportanttolearntouseevidenceinargumentativewriting,becausewithoutevidence,youcan’
1 Weoftenhearpeopleasksuchaquestion:Whydobadthingshappentogoodpeople?Theproblemis:Whatkindofpeoplearego
Wheredidthemoviesbegin?ItisoftensaidthattheyareanAmericaninvention,andthisisnotentirelytree.Themotionpict
A、Youngpeopleneedmoreexercisethanotherpeople.B、Onecanlivelongerthanothersifonehasmoreexercisewhenoneisyoun
Justafewweeksago,economistsandmarketanalystswereexpectingtheFederalReservetocutshortterminterestratesonefin
Anyonemakinglongdrivesthissummerwillnoticeanewdimensiontocontemporaryinequality:awideninggapbetweentheuserso
A、payingtoolittleattentiontothisissueB、followingtheUStoocloselyC、toomuchconfidenceaboutitsownabilityD、lackof
A、KofiAnnansaidthiswasgoingtobeafive-to-tenyeareffortcosting250milliondollarsB、Humanisspendingninehundredbi
A、Therearealtogether15candidatesinthepresidentialelection.B、Apro-Westernreformerwonmorevotesthananyothercandid
随机试题
患者,女性,43岁,近1年反复发作尿频、尿急、尿痛史,肾区叩击痛(+)。遵医嘱测尿肌酸时,尿标本中加入甲苯防腐的方法是
500mA型X线机可选择的最大管电流是
A.白色B.淡黄色C.淡绿色D.淡蓝色E.淡红色急诊处方的颜色是
下列哪项是外感腰痛的最主要的病因
下面哪项()是利用地籍图所不能了解到的。
工程项目管理中的项目诊断基本程序的第一步是()。
基本的家庭模型有三种:青年家庭、中年家庭和老年家庭。
(2009年考试真题)()是指公司适应经济环境变化和利用投资机会的能力分析。
某演员参加一次商业演出,合同规定不含税演出费20000元,个人所得税为演出公司代付,则代付个人所得税为()元。
在神经纤维一次兴奋后的相对不应期时
最新回复
(
0
)