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
Immune Functions The immune system is equal in complexity to the combined intricacies of the brain and nervous system. The s
Immune Functions The immune system is equal in complexity to the combined intricacies of the brain and nervous system. The s
admin
2011-04-15
55
问题
Immune Functions
The immune system is equal in complexity to the combined intricacies of the brain and nervous system. The success of the immune system in defending the body relies on a dynamic regulatory communication network consisting of millions and millions of cells. Organized into sets and subsets, these cells pass information back and forth like clouds of bees flying around a hive(蜂巢). The result is a sensitive system of checks and balances that produces an immune response that is prompt, appropriate, effective and self-limiting.
At the heart of the immune system is the ability to distinguish between self and nonself. When immune defenders encounter cells or organisms carrying foreign or nonself molecules, the immune troops move quickly to eliminate the intruders(入侵者).Virtually every body cell carries distinctive molecules that identify it as self. The body’s immune defenses do not normally attack tissues that carry a self - marker. Rather, immune cells and other body cells coexist peaceably in a state known as self - tolerance. When a normally functioning immune system attacks a nonself molecule, the system has the ability to "remember" the specifics of the foreign body. Upon subsequent encounters with the same species of molecules, the immune system reacts accordingly. With the possible exception of antibodies(抗体) passed during lactation (授乳期), this so called immune system memory is not inherited. Despite the occurrence of a virus in your family, your immune system must "learn" from experience with the many millions of distinctive nonself molecules in the sen of microbes(微生物) in which we live. Learning entails producing the appropriate molecules and cells to match up with and counteract each nonself invader.
Any substance capable of triggering an immune response is called an antigen (抗原) . Antigens are not to be confused with allergens (过敏原), which are most often harmless substances that provoke the immune system to set off the inappropriate and harmful response known as allergy. An antigen can be a virus, a bacterium, or even a portion or product of one of these organisms. Tissues or cells from another individual also act as antigens, because the immune system recognizes transplanted tissues as foreign, it rejects them. The body will even reject nourishing proteins unless they are first broken down by the digestive system into their primary, nonantigenic building blocks. An antigen announces its foreignness by means of intricate and characteristic shapes called epitopes(抗原表位), which protrude(突出) from its surface. Most antigens even the simplest microbes, carry several different kinds of epitopes on their surface; some may even carry several hundreds. Some epitopes will be more effective than others at stimulating an immune response. Only in abnormal situations does the immune system wrongly identify self as nonself and execute a misdirected immune attack.
What is used to describe the communication network consisting of cells in the immune system? ______
选项
A、The immune system’s memory.
B、Immune troops eliminating intruders.
C、Bees flying around a hive.
D、A sea of microbes.
答案
C
解析
本题难度较大, 需要吃透题干意思和原文句意。答案依据在文章第一段倒数第二句:Organized into sets and subsets, these cells pass information back and forth like clouds of bees flying around a hive(蜂巢).本题问可以用什么来描述免疫系统的信息交流网络?根据原文句意, 很明显, 答案是C。
转载请注明原文地址:https://kaotiyun.com/show/uZmd777K
本试题收录于:
职称英语卫生类A级题库职称英语分类
0
职称英语卫生类A级
职称英语
相关试题推荐
Youaregoingtoreadamagazinearticleaboutanartistwhopaintsflowers.Forquestions8-14,choosetheanswer(A,B,CorD
THOMASEDISONOnthenightof21October1931,millionsofAmericanstookpartinacoast-to-coastceremonytocommemorate
A、Lockyourcyclenearthisgatebeforeentering.B、Cyclistsshoulduseadifferententrancewhenthisoneislocked.C、Ifthes
AFindaPlacetoWorkonBImplementingaWorkableFilingSystemCWhatIsaGoodFilingSystemDHowtoInvestinaRollin
BetterControlofTBSeenIfaFasterCureIsFoundTheWorldHealthOrganizationestimatesthataboutone-thirdofallpeoplea
Examinationpapersoftheclassweremarkedwithoutbias.
FriendsMayBeKeytoLivingLongerLookingforthesecretofalonglife?Lookcloselyatyourfriends.Newresearchsugges
AwithoutpityBsadandlonelyCemotionallyhealthyDwithoutrealloveforthemEasenseofsecurityFalonelywolfTheab
Theresidentsinthisareaaremostlyrichenoughtoaffordthiskindofproducts.
Accordingtothemostrecentresearchonparenting,caretakerstendtousethreestrategiesfordiscipliningchildren.Power
随机试题
我国《刑事诉讼法》第12条规定:“未经人民法院依法判决,对任何人都不得确定有罪。”该规定是否意味着我国已经确立了无罪推定的原则?为什么?(中国青年政治学院2008年研)
小儿头颈部烧伤应占体表面积的百分数是()
骨关节炎主要受累关节为
水泥混凝土路面板应设置胀缝的地方有()。
防水混凝土的配合比应符合下列()规定。
()是凭样品采购,即以样品表示标的物品质,并以样品作为交货依据的采购关系。
小说中的重要人物通常都具有鲜明的特点,以至于提到这些特点我们一下子就会想到这些人物。从人格特质的角度出发,这些特点属于这些人物的()
为了证明碳水化合物是肥胖背后的凶手,科学家进行了相关实验。研究人员将120名超重志愿者分成两组,分别食用以粗加工谷物食品、蔬菜为主的低脂饮食和以肉为主的低碳水化合物饮食各24周。结果表明,低碳水化合物节食者减掉的体重是低脂节食者的两倍。因此研究人员得出结论
以下程序的输出结果是()。#include<iostream.h>voidmain(){inta=0,i;for(i=1;i<5;i++){switch(i){case0:c
Ofalltheareasoflearningthemostimportantisthedevelopmentofattitudes.Emotionalreactionsaswellaslogicalthought
最新回复
(
0
)