医学专业英语-阅读一分册-第二章

1、精选优质文档-倾情为你奉上Human DiseasesThe brief survey of the human body in Chapter One has given us a glimpse into two different studies that are considered the fundamentals of medical sciences, namely anatomy and physiology. However, the picture is not complete without considering pathology, the science that

2、 deals with the structural and functional changes produced by the disease. In fact, the modern approach to the study of disorder emphasizes the close relationship of the pathological and physiological aspects and the need to understand the fundamentals of each in treating any body diseases.第一章中，通过对人

3、体的概论，即解剖学与生理学，我们对两种被认为是医学基础的不同学科有了一个大致的印象。然而如果我们不考虑病理学，这门涉及由疾病带来的结构和功能变化的学科，上述的人体概论就不是完整的。实际上，现代对疾病的研究方法强调了病理学与生理学方面的密切关系，强调了我们在治疗任何人体疾病方面需要了解病理学与生理学基础的重要性。Then what is a disease? It may be defined as a condition that impairs the proper function of the body or of one of its parts. Every living thing

4、, both plants and animals, can succumb to disease. People, for example, are often infected by tiny bacteria, but bacteria, in turn, can be infected by even more minute viruses.那么什么是疾病呢？它可能被定义为正常的功能或是部分功能遭受损害时的一种状态。每一种生物、植物和动物，都会受制于疾病。例如，人类常常被微小的细菌所感染，但是，反过来说，细菌又能够被甚至更加微小的病毒所感染。Hundreds of different

5、diseases exist. Each has its own particular set of symptoms and signs, clues that enable a physician to diagnose the problem. A symptom is something a patient can detect, such as fever, bleeding, or pain. A sign is something a doctor can detect, such as a swollen blood vessel or an enlarged internal

6、 body organ.许多种疾病存在于世。每一种都有其特定的症状、征兆和线索，医生能以此诊断疾病之所在。症状是病人自己就能觉察到的，比如，高烧、流血，或是疼痛。而征兆则是医生能够观察到的，比如，血管扩张或是体内器官肿大。Diseases can be classified differently. For instance, an epidemic disease is one that strikes many persons in a community. When it strikes the same region year after year it is an endemic d

7、isease. An acute disease has a quick onset and runs a short course. An acute heart attack, for example, often hits without warning and can be quickly fatal. A chronic disease has a slow onset and runs a sometimes years-long course. The gradual onset and long course of rheumatic fever makes it a chro

8、nic ailment. Between the acute and chronic, another type is called subacute.疾病可以划分为不同的种类，例如，流行病是一种在某一社区内侵袭许多人的疾病。当它年复一年地袭击同一社区，就成了一种地方病。急性病发作快，但病程短，举个例子来说，急性心脏病发作常常没有前兆，而且会很快致命。慢性病发作则慢，但病程有时会长达几年之久。风湿热正是由于发病慢、病程长而成为一种慢性失调病（慢性病）。而介于急性与慢性之间的另一种类型，就被称为亚急性。Diseases can also be classified by their causat

9、ive agents. For instance, an infectious, or communicable, disease is the one that can be passed between persons such as by means of airborne droplets from a cough or sneeze. Tiny organisms such as bacteria and fungi can produce infectious diseases. So can viruses. So can tiny worms. Whatever the cau

10、sative agent might be, it survives in the person it infects and is passed on to another. Sometimes, a disease-producing organism gets into a person who shows no symptoms of the disease. The asymptomatic carrier can then pass the disease on to someone else without even knowing he has it. 疾病也可以依其病原体来划

11、分，例如，传染病也叫作可传播的疾病，就是一种通过咳嗽和打喷嚏造成的空气小粒来传播的疾病。极小的有机体，如，细菌和真菌可导致传染病。病毒和小虫子也不例外。不论病原体会是什么样，只要它存活于人体内就能够传染给别人。有时，一个致病的有机体侵人人体后，该人却没有显示带病的症状。于是无症状的病原携带者甚至在自己也不知情的情况下就把疾病传染给了他人。Noninfectious diseases are caused by malfunctions of the body. These include organ or tissue degeneration, erratic cell growth, an

12、d faulty blood formation and flow. Also included are disturbances of the stomach and intestine, the endocrine system, and the urinary and reproductive systems. Some diseases can be caused by diet deficiencies, lapses in the body's defense system, or a poorly operating nervous system. 非传染性疾病是由身体功

13、能失调引起的。这包括血管或组织退化、异常细胞生成，以及异常的血液生成和血液循环。当然其中也包括胃、肠、内分泌系统和泌尿生殖系统的紊乱。一些疾病也可能是由饮食不足、身体抵抗力下降、或是神经系统工作不造成的。Disability and illnesses can also be provoked by psychological and social factors. These ailments include drug addiction, obesity, malnutrition, and pollution-caused health problems. 心理因素和社会因素也会引发残废

14、和疾病，这些病包括吸毒成性、肥胖、营养不良和由污染造成的健康问题。Furthermore, a thousand or more inheritable birth defects result from alternations in gene patterns. Since tiny genes are responsible for producing the many chemicals needed by the body, missing or improperly operating genes can seriously impair health. Genetic disor

15、ders that affect body chemistry are called inborn errors of metabolism. Some forms of mental retardation are hereditary. 而且，有上千种乃至为数更多的遗传性出生缺陷是由于基因变化而造成的。由于小小的基因负责着生产许多身体所需的化学物质，它的遗失或是工作状态不良都会严重损害健康。因基因失调而被影响了的身体化学反应被称之为先天性代谢失调。一些眢力发育迟缓就是因遗传而造成的。How Germs Invade the Body病菌是怎样侵袭身体Humans live in a wor

16、ld where many other living things compete for food and places to breed. The pathogenic organisms, or pathogens, often broadly called germs, that cause many diseases are able to invade the human body and use its cells and fluids for their own needs. Ordinarily, the body's defense system can ward

17、off these invaders.人类生活在有一个有许多其它生物竞争食物和求得繁衍的世界里。很多致病的有机体或病原体，通常被我们广义地称为病菌的东西能侵入人体并利用其细胞和组织液来供它们自身的需求。一般来讲，身体防御系统能够阻止这些入侵者。Pathogenic organisms can enter the body in various ways. Some - such as these that cause the common cold, pneumonia, and tuberculosis - are breathed in. Others - such as those th

18、at cause venereal diseases - enter through sexual contact of human bodies. Still others - such as those that cause hepatitis, colitis, cholera, and typhoid fever-get in the body through contaminated food, water or utensils.病原有机体能通过多种方式进入身体。它们的一些是被呼吸进体内的，比如那些引起普通感冒、肺炎和肺结核的病菌；其它的是通过人体性接触进入的，比如那些引起花柳病的

19、病原体；还有另外的一些是通过污染了的食物、水或器皿进入体内的，比如那些引起肝炎、霍乱和伤寒热的病原体。Insects can spread disease by acting as vectors, or carriers. Flies can carry germs from human waste or other tainted materials to food and beverages. Germs may also enter the body through the bite of a mosquito, louse, or other insect vector.昆虫作为媒介

20、动物或是病原携带者会传播疾病。苍蝇能将病菌从人类的废物或其它腐烂的材料中带到食物和饮料中去。通过蚊子、虱子或其它媒介动物的叮咬，病菌也可能进入体内。How the Body Fights Disease身体是怎样抵抗疾病的As a first line of defense, a healthy body has a number of physical barriers against infection. The skin and mucous membranes covering the body or lining its openings offer considerable res

21、istance to invasion by bacteria and other infectious organisms. If these physical barriers are injured or burned, infection resistance drops. In minor cases, only boils or pimples may develop. In major cases, however, large areas of the body might become infected.作为第一条防线，一个健康的身体有许多屏障来抵御感染的发生。覆盖在体表或者

22、器官开口处的皮肤和粘膜能在很大程度上抵抗细菌或其它感染体的入侵。如果这些屏障遭到了损坏或烧伤，身体对感染的抵抗力就会下降。在一些病情较轻的病例中，疥子和小脓胞可能会发生。在病情较重的病例中，身体的大面积区域则可能会被感染。Breathing passages are especially vulnerable to infection. Fortunately, they are lined with mucus-secreting cells that trap tiny organisms and dust particles. Also, minute hairs called cili

23、a line the breathing passages, wave like a field of wheat, and gently sweep matter out of the respiratory tract. In addition, foreign matter in the breathing passages can often be ejected by nose blowing, coughing, sneezing, and throat clearing. Unfortunately, repeated infection, smoking and other c

24、auses can damage the respiratory passageways and make them more susceptible to infection.呼吸通道尤其容易受到感染，幸运的是，呼吸道内覆盖满了能分泌粘液的细胞，它们能捕捉微小的有机体和尘粒。另外，被叫做纤毛的细小的毛发也覆盖了呼吸道，它们象微风下麦田里的小麦一样舞动着，轻轻地将异物扫出呼吸道。除此之外，呼吸道内的异物还常常因为擤鼻涕、咳嗽、打喷嚏和清喉咙而被弹出。不幸的是反复感染、抽烟或其它别的原因会损坏呼吸道，并且使它们容易受到感染Many potential invaders cannot stand

25、body temperature (98.6 °F or 37 °C). Even those that thrive at that temperature may be destroyed when the body assumes higher, fever temperatures.很多潜在的人侵者不能在华氏98.6度或摄氏37度下生存。如果体温再升高一点，达到高烧温度，甚至一些在先前温度下能蓬勃繁殖的病菌也可能会因此而遭到毁灭。Wax in the outer ear canals and tears from eye ducts can slow the gro

26、wth of some bacteria. And stomach acid can destroy certain swallowed germs.外耳道里的蜡质和泪管里的眼泪能减缓一些细菌的生长速度，而胃酸也能毁掉某种吞食进去的病菌。The body's second line of defense is in the blood and lymph. Certain white blood cells flock to infected areas and try to localize the infection by forming pus-filled abscesses.

27、 Unless the abscess breaks and allows the pus to drain, the infection is likely to spread. When this happens, the infection is first blocked by local lymph glands. For example, an infection in the hand travels up the arm, producing red streaks and swollen, tender lymph glands in the armpit. Unless t

28、he infection is brought under control, it will result in blood poisoning. 身体的第二条防线是在血液和淋巴里。某些白细胞群聚集在被感染区，并通过形成脓块使感染局部化。如果脓块不破裂，里面的脓不排除掉，感染很可能会扩大。当这发生时，感染首先被该区域的淋巴腺挡住。例如，手上的感染在向上传到手臂时，手臂上会出现红线条，腋窝处会肿胀，有触痛。如果不及时控制住感染的上传，将会导致血液中毒。Phagocytes are located at various sites to minimize infection. One type i

29、n the spleen and liver keeps the blood clean. Others in such high-risk areas as the walls of the bronchi and the intestines remove certain bacteria and shattered cells. 吞噬细胞处于身体多种不同的部位而使得感染的机会变小。位于肝脾内的一类能使身体的血液保持干净。其它的位于像支气管壁和肠壁这样高危险区的类型能清除某类细茵和已解体的细胞。How We Become Immune to Disease我们是怎样变得对疾病有免疫力的身体

30、处理感染有其特殊的方法。The body has a special way of handling infection. It has a system that fends off the first traces of an infectious substance and then, through a "memory," gives the body a long-lasting immunity against future attacks by the same kind of invader.它有一个系统，能够一开始就阻止感染性物质的侵袭，然后通过“记忆”，

31、它能给身体个长期的免疫力来抵抗将来由同种入侵者引起的侵袭。Many substances could harm the body if they ever entered it. These substances, or antigens, range from bacteria and pollen to a transplanted organ (viewed by the body as an invader). To fight them the body makes special chemicals known as antibodies.许多物质对身体有害，如果它们一旦进入身体的

32、话。这些物质，或称为抗原，包括从细菌，花粉到被移植的器官都被身体视为人侵者。为了抵抗它们身体制造出了特殊的化学物质，这就是抗体。Antibodies are a class of proteins called immunoglobulins. Each antibody is made of a heavy chain of chemical subunits, or amino acids, and a light chain of them. The light chain has special sites where the amino acids can link with the

33、ir complements on the antigen molecule. When an antibody hooks up with an antigen, it often puts the antigen out of action by inactivating or covering a key portion of the harmful substance. In some cases, through the process of opsonization, antibodies "butter" the surface of some antigen

34、s and make them "tastier" to phagocytes, which engulf the antigens. Sometimes an antibody hooks to a bacterial antigen but needs an intermediate, or complement, to actually destroy the bacterium. As the antibody- antigen complex circulates in the blood, the complex "fixes" comple

35、ment to it. In turn, the complement causes powerful enzymes to eat through the bacterial cell wall and make the organism burst.抗体是一类被称为免疫球蛋白的蛋白质。每一个抗体由一条化学亚单位（即氨基酸）的重链和一条轻链所构成。这条轻链上有特别的部位，在那里，氨基酸能使其补体和抗原分子相连。当一个抗体与一个抗原粘和上以后，氨基酸常通过使抗原失去活性或覆盖，它的关键有害部分来使抗原失去其作用。在某些情况下，通过调理素作用的过程，抗体在抗原表面涂抹上一些“奶油”，让吞噬细胞更

36、喜欢吞噬它们。在另一些情况下，抗体和一个细菌抗原粘和上以后，却需要一个中间体，或补体来实施对该细菌的消灭。于是，当抗体和抗原的结合体随血液循环时，该结合体会有一个补体附体。结果是补体产生一种强烈的酶，咬穿了细菌的细胞壁，细菌有机体就爆开了。There are several kinds of immunoglobulins - IgM, the largest; IgG, the most plentiful and versatile; and IgA, the next most plentiful and specially adapted to work in areas where

37、body secretions could damage other antibodies. Other immunoglobulins are tied in with allergic reactions, IgM is made at the first signs of an antigen, and it is later supplanted by the more effective IgG.抗体有若干种免疫球蛋白：体积最大的是igM，数量最多、用途最多的是IgG，而IgA的数量次多，但它特别适合在其它抗体易被身体内分泌物杀死的部位工作，还有其它的免疫球蛋白专门在过敏物质出现时启

38、动。一有抗原出现，igM首先被产生，稍后被更有效的IgG所取代。When infection first strikes, the immunity system does not seem to be working. During the first day or so, antibodies against the infection cannot be found in the blood. But this is only because the basic cells involved in antibody production have been triggered by th

39、e presence of antigen to multiply themselves. The antibody level starts to rise on about the second day of infection and then zooms upward. By the fifth day the antibody level has risen a thousandfold.当传染病首次进攻，免疫系统似乎没有运转起来。在第一天左右，血液中没有发现对付传染病的抗体。但是，这只是因为涉及抗体制造的基本细胞已被当前的抗原存在所触发而正准备开始繁殖。大约在感染的第二天，抗体水平

40、开始升高，接着直线上升，大约在第五天抗体水平已升高了千倍。The first antibodies, the large IgM type, are not the best qualified to fight a wide range of antigens, but they are particularly effective against bacteria. The more versatile IgG is circulating in the blood on about the fourth day of infection. Its production is stimul

41、ated by the rising level of IgM in the blood. At this time, IgM production drops off and the immunity systems concentrates on making IgG. The IgG type of antibody sticks well to antigens and eventually covers them so that the antigens can no longer stimulate the immune response and IgG production is

42、 switched off. This is an example of negative feedback control. 最开始出现的抗体，及大个的IgM，不是对付广谱抗原的最好选择。但它们对付细菌特别有效。而用途广泛的IgG自感染第四天开始在血液中循环，它的产生是因为受了血液中IgM水平增高的刺激。至此，IgM的产量下降，免疫系统集中制造IgG，IgG能很好的与抗原粘连，甚至能覆盖抗原，使抗原不能再激发免疫反应，而系统最终停止生产IgG。这是消极反馈控制的一个例子。 第一章中，通过对人体的概论，即解剖学与生理学，我们对两种被认为是医学基础的不同学科有了一个大致的印象。然而如果我们不考虑

43、病理学，这门涉及由疾病带来的结构和功能变化的学科，上述的人体概论就不是完整的。实际上，现代对疾病的研究方法强调了病理学与生理学方面的密切关系，强调了我们在治疗任何人体疾病方面需要了解病理学与生理学基础的重要性。 那么什么是疾病呢？它可能被定义为正常的功能或是部分功能遭受损害时的一种状态。每一种生物、植物和动物，都会受制于疾病。例如，人类常常被微小的细菌所感染，但是，反过来说，细菌又能够被甚至更加微小的病毒所感染。 许多种疾病存在于世。每一种都有其特定的症状、征兆和线索，医生能以此诊断疾病之所在。症状是病人自己就能觉察到的，比如，高烧、流血，或是疼痛。而征兆则是医生能够观察到的，比如，血管扩张或

44、是体内器官肿大。 疾病可以划分为不同的种类，例如，流行病是一种在某一社区内侵袭许多人的疾病。当它年复一年地袭击同一社区，就成了一种地方病。急性病发作快，但病程短，举个例子来说，急性心脏病发作常常没有前兆，而且会很快致命。慢性病发作则慢，但病程有时会长达几年之久。风湿热正是由于发病慢、病程长而成为一种慢性失调病（慢性病）。而介于急性与慢性之间的另一种类型，就被称为亚急性。 疾病也可以依其病原体来划分，例如，传染病也叫作可传播的疾病，就是一种通过咳嗽和打喷嚏造成的空气小粒来传播的疾病。极小的有机体，如，细菌和真菌可导致传染病。病毒和小虫子也不例外。不论病原体会是什么样，只要它存活于人体内就能够传染

45、给别人。有时，一个致病的有机体侵人人体后，该人却没有显示带病的症状。于是无症状的病原携带者甚至在自己也不知情的情况下就把疾病传染给了他人。 非传染性疾病是由身体功能失调引起的。这包括血管或组织退化、异常细胞生成，以及异常的血液生成和血液循环。当然其中也包括胃、肠、内分泌系统和泌尿生殖系统的紊乱。一些疾病也可能是由饮食不足、身体抵抗力下降、或是神经系统工作不造成的。 心理因素和社会因素也会引发残废和疾病，这些病包括吸毒成性、肥胖、营养不良和由污染造成的健康问题。 而且，有上千种乃至为数更多的遗传性出生缺陷是由于基因变化而造成的。由于小小的基因负责着生产许多身体所需的化学物质，它的遗失或是工作状态

46、不良都会严重损害健康。因基因失调而被影响了的身体化学反应被称之为先天性代谢失调。一些眢力发育迟缓就是因遗传而造成的。病菌是怎样侵袭身体 人类生活在有一个有许多其它生物竞争食物和求得繁衍的世界里。很多致病的有机体或病原体，通常被我们广义地称为病菌的东西能侵入人体并利用其细胞和组织液来供它们自身的需求。一般来讲，身体防御系统能够阻止这些入侵者。 病原有机体能通过多种方式进入身体。它们的一些是被呼吸进体内的，比如那些引起普通感冒、肺炎和肺结核的病菌；其它的是通过人体性接触进入的，比如那些引起花柳病的病原体；还有另外的一些是通过污染了的食物、水或器皿进入体内的，比如那些引起肝炎、霍乱和伤寒热的病原体。 昆虫作为媒介动物或是病原携带者会传播疾病。苍蝇能将病菌从人类的废物或其它腐烂的材料中带到食物和饮料中去。通过蚊子、虱子或其它媒介动物的叮咬，病菌也可能进入体内。身体是怎样抵抗疾病的 作为第一条防线，一个健康的身体有许多屏障来抵御感染的发生。覆盖在体表或者器官开口处的皮肤和