【正文】 and controls body responses by transmitting electrical impulses. 神經(jīng)組織 : 組成大腦、脊椎和神經(jīng)。它是通過動(dòng)作電位來超空身體。 The simplest tissues are membranes. Mucous membranes secrete thick fluid called mucus that protects underlying tissues. Serous membranes secrete a thin, watery fluid. They line body cavities and cover organs. 最簡單的組織就是膜。粘液膜分泌出粘稠的膠液，起得組織保護(hù)作用。粘液組織分泌出較稀的粘液，起得身體導(dǎo)管的分界和覆蓋著各個(gè)器官。Human diseasesIn this passage you will learn: and pathology classification of diseases ’ invasion of the human body body’s defense against invasion body’s immunity to diseases The 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 plete without considering pathology, the science that 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，通過對人體的概論，即解剖學(xué)與生理學(xué)，我們對兩種被認(rèn)為是醫(yī)學(xué)基礎(chǔ)的不同學(xué)科有了一個(gè)大致的印象。然而如果我們不考慮病理學(xué)，這門涉及由疾病帶來的結(jié)構(gòu)和功能變化的學(xué)科，上述的人體概論就不是完整的。實(shí)際上，現(xiàn)代對疾病的研究方法強(qiáng)調(diào)了病理學(xué)與生理學(xué)方面的密切關(guān)系，強(qiáng)調(diào)了我們在治療任何人體疾病方面需要了解病理學(xué)與生理學(xué)基礎(chǔ)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, 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？它可能被定義為正常的功能或是部分功能遭受損害時(shí)的一種狀態(tài)。每一種生物、植物和動(dòng)物，都會(huì)受制于疾病。例如，人類常常被微小的細(xì)菌所感染，但是，反過來說，細(xì)菌又能夠被甚至更加微小的病毒所感染。 Hundreds of different 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 body organ. 許多種疾病存在于世。每一種都有其特定的癥狀、征兆和線索，醫(yī)生能以此診斷疾病之所在。癥狀是病人自己就能覺察到的，比如，高燒、流血，或是疼痛。而征兆則是醫(yī)生能夠觀察到的，比如，血管擴(kuò)張或是體內(nèi)器官腫大。 Diseases can be classified differently. For instance, an epidemic disease is one that strikes many persons in a munity. When it strikes the same region year after year it is an endemic disease. 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 yearslong course. The gradual onset and long course of rheumatic fever makes it a chronic ailment. Between the acute and chronic, another type is called subacute. 疾病可以劃分為不同的種類，例如，流行病是一種在某一社區(qū)內(nèi)侵襲許多人的疾病。當(dāng)它年復(fù)一年地襲擊同一社區(qū)，就成了一種地方病。急性病發(fā)作快，但病程短，舉個(gè)例子來說，急性心臟病發(fā)作常常沒有前兆，而且會(huì)很快致命。慢性病發(fā)作則慢，但病程有時(shí)會(huì)長達(dá)幾年之久。風(fēng)濕熱正是由于發(fā)病慢、病程長而成為一種慢性失調(diào)?。圆。６橛诩毙耘c慢性之間的另一種類型，就被稱為亞急性。 Diseases can also be classified by their causative agents. For instance, an infectious, or municable, 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 causative agent might be, it survives in the person it infects and is passed on to another. Sometimes, a diseaseproducing 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體來劃分，例如，傳染病也叫作可傳播的疾病，就是一種通過咳嗽和打噴嚏造成的空氣小粒來傳播的疾病。極小的有機(jī)體，如，細(xì)菌和真菌可導(dǎo)致傳染病。病毒和小蟲子也不例外。不論病原體會(huì)是什么樣，只要它存活于人體內(nèi)就能夠傳染給別人。有時(shí)，一個(gè)致病的有機(jī)體侵人人體后，該人卻沒有顯示帶病的癥狀。于是無癥狀的病原攜帶者甚至在自己也不知情的情況下就把疾病傳染給了他人。 Noninfectious diseases are caused by malfunctions of the body. These include organ or tissue degeneration, erratic cell growth, and 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 body39。s defense system, or a poorly operating nervous system. 非傳染性疾病是由身體功能失調(diào)引起的。這包括血管或組織退化、異常細(xì)胞生成，以及異常的血液生成和血液循環(huán)。當(dāng)然其中也包括胃、腸、內(nèi)分泌系統(tǒng)和泌尿生殖系統(tǒng)的紊亂。一些疾病也可能是由飲食不足、身體抵抗力下降、或是神經(jīng)系統(tǒng)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 pollutioncaused health problems. 心理因素和社會(huì)因素也會(huì)引發(fā)殘廢和疾病，這些病包括吸毒成性、肥胖、營養(yǎng)不良和由污染造成的健康問題。 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 disorders that affect body chemistry are called inborn errors of metabolism. Some forms of mental retardation are hereditary. 而且，有上千種乃至為數(shù)更多的遺傳性出生缺陷是由于基因變化而造成的。由于小小的基因負(fù)責(zé)著生產(chǎn)許多身體所需的化學(xué)物質(zhì)，它的遺失或是工作狀態(tài)不良都會(huì)嚴(yán)重?fù)p害健康。因基因失調(diào)而被影響了的身體化學(xué)反應(yīng)被稱之為先天性代謝失調(diào)。一些眢力發(fā)育遲緩就是因遺傳而造成的。 How Germs Invade the Body病菌是怎樣侵襲身體 Humans live in a world where many other living things pete 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 body39。s defense system can ward off these 。很多致病的有機(jī)體或病原體，通常被我們廣義地稱為病菌的東西能侵入人體并利用其細(xì)胞和組織液來供它們自身的需求。一般來講，身體防御系統(tǒng)能夠阻止這些入侵者。 Pathogenic organisms can enter the body in various ways. Some such as these that cause the mon cold, pneumonia, and tuberculosis are breathed in. Others such as those that cause venereal diseases enter through sexual contact of human bodies. Still others such as those that cause hepatitis, colitis, cholera, and typhoid feverget in the body through contaminated food, water or utensils. 病原有機(jī)體能通過多種方式進(jìn)入身體。它們的一些是被呼吸進(jìn)體內(nèi)的，比如那些引起普通感冒、肺炎和肺結(jié)核的病菌；其它的是通過人體性接觸進(jìn)入的，比如那些引起花柳病的病原體；還有另外的一些是通過污染了的食物、水或器皿進(jìn)入體內(nèi)的，比如那些引起肝炎、霍亂和傷寒熱的病原體。 Insects can spread disease by a