药学英语第五版原文翻译

1、文档编码 : CG5C5Y2W3J3 HI7A4N2L4J5 ZD2E8P8H10V8Introduction to Physiology 生理学简介Introduction 介绍Physiology is the study of the functions of living matter. It is concerned with how an organism performs its varied activities: how it 生理学是争论生物体功能的科学；它 争论生物体如何进行各种活动,如何饮食,feeds, how it moves, how it adapts to c

2、hanging circumstances, how it 如何运动, 如何适应不断转变的环境,如何spawns new generations. The subject is vast and embraces the whole of 繁殖后代； 这门学科包罗万象,涵盖了生物life. The success of physiology in explaining how organisms perform their daily tasks is based on the notion that they are intricate and exquisite machines whos

3、e operation is governed by the laws of physics and 体整个生命过程；生理学成功地说明白生 物体如何进行日常活动,基于的观点是生 物体好比是结构复杂而敏捷的机器,其操chemistry. 作受物理和化学规律把握；Although some processes are similar across the whole spectrum of 尽管从生物学整个范畴看,生物体某biology the replication of the genetic code for or example些活动过程是相像的 如基因编码的复specific to pa

4、rticular groups of organisms. For this reason it is necessary to divide the subject into various parts such as bacterial physiology, plant physiology, and animal physiology.制 但许多过程仍是某些生物体群组特 有的；鉴于此有必要将这门学科分成不同部分争论, 如细菌生理学、 植物生理学和动To study how an animal works it is first necessary to know how it is 物

5、生理学；built. A full appreciation of the physiology of an organism must therefore be based on a sound knowledge of its anatomy. Experiments can then be carried out to establish how particular parts perform their functions. Although there have been many important physiological investigations on human vo

6、lunteers, the need for precise control over the experimental conditions has meant that much of our present physiological knowledge has been derived from studies on other animals such as frogs, rabbits, cats, 要争论一种动物如何活动,第一需要 明白它的构成；要充分明白一个生物体的 生理学活动就必需把握全面的解剖学知 识；一个生物体的各部分起着什么作用可 通过试验观看得知；尽管我们对理想者进

7、行了许多重要的生理调查,但是试验条件 需要精确把握,所以我们当前大多生理知and dogs. When it is clear that a specific physiological process has a 识仍是源于对其它动物如青蛙,兔子,猫和common basis in a wide variety of animal species, it is reasonable to assume that the same principles will apply to humans. The knowledge gained from this approach has given

8、 us a great insight into human 狗等的争论；当我们明确大多数动物物种 的特定生理过程存在共同之处时,相同的 生理原理适用于人类也是合理的；通过这physiology and endowed us with a solid foundation for the effective 种方法, 我们获得了大量的学问,从而让我treatment of many diseases.The building blocks of the body are the cells, which are grouped 们对人类生理学有了更深化的明白,为我 们有效治疗许多疾病供应了一个

9、坚实的基together to form tissues. The principal types of tissue are epithelial, 础；connective, nervous, and muscular, each with its own characteristics. Many connective tissues have relatively few cells but have an extensive 机体的基本组成物质是细胞,细胞结 合在一起形成组织；组织的基本类型有上extracellular matrix. In contrast, smooth mus

10、cle consists of densely 皮组织, 结缔组织, 神经组织和肌组织,每packed layers of muscle cells linked together via specific cell junctions. Organs such as the brain, the heart, the lungs, the intestines, and the liver are formed by the aggregation of different kinds of tissues. The organs are themselves parts of distin

11、ct physiological systems. The heart and blood vessels form the cardiovascular system; the lungs, trachea, and bronchi together with the chest wall and diaphragm form the respiratory system; the skeleton and skeletal muscles form the musculoskeletal system; the brain, spinal cord, autonomic nerves an

12、d ganglia, and peripheral somatic nerves form the nervous system, and so on.Cells differ widely in form and function but they all have certain common characteristics. Firstly, they are bounded by a limiting membrane, the plasma membrane. Secondly, they have the ability to break 类组织都有各自的特点；许多结缔组织中 细胞

13、量相对较少,但是有大量的细胞外基 质；相比而言, 光滑的肌组织由大量密密麻 麻的肌细胞通过特定的细胞连接组成；各 种器官如脑, 心脏,肺,小肠和肝等由不同 种类的组织集合而成；这些器官是不同生 理系统的组成部分；心脏和血管组成心血 管系统； 肺,器官, 支气管, 胸壁和膈肌组 成呼吸系统；骨骼和骨骼肌组成骨骼肌系 统；大脑,脊髓,自主神经和神经中枢以及 四周躯体神经组成神经系统等等；细胞在形体和功能上差异很大,但是down large molecules to smaller ones to liberate energy for their activities. 它们有某些共同的特点；第一

14、,它们由限制Thirdly, at some point in their life history, they possess a nucleus which contains genetic information in the form of deoxyribonucleic acid DNA.膜包被, 即细胞质膜； 其次,细胞有把大分 子分解为小分子来释放活动所需能量的能Living cells continually transform materials. They break down 力；第三,在生命过程中某个阶段,细胞体glucose and fats to provide

15、energy for other activities such as motility and 内存在一个以脱氧核糖核酸 DNA 形式包the synthesis of proteins for growth and repair. These chemical changes are collectively called metabolism. The breakdown of large molecules to smaller ones is called catabolism and the synthesis of large molecules from smaller one

16、s anabolism. In the course of evolution, cells began to differentiate to serve different functions. Some developed the ability to contract muscle cells, others to conduct electrical signals nerve cells. A further group developed the ability to secrete different substances such as hormones or 含基因信息的细

17、胞核；活体细胞不断转化物质；它们为其它 活动供应能量分解葡萄糖和脂肪,比如自 身生长和修复所需的蛋白质运动和合成；这些化学变化统称为新陈代谢；把大分子 分解为小分子的过程称为分解代谢,小分 子合成大分子的过程称为合成代谢；细胞在进化过程中不断分化进行不同enzymes. During embryological development, this process of 的功能活动； 有些细胞具有收缩才能（如肌differentiation is re-enacted as many different types of cell are formed from the fertilized e

18、gg. Most tissues contain a mixture of cell types. For example, blood consists of red cells, white cells, and platelets. Red cells transport oxygen around the body. The white cells play an important role in defense against infection and the platelets are vital components in the process of blood clott

19、ing. There are a number of different types of connective tissue but all are characterized by having cells distributed within an extensive noncellular matrix. Nerve tissue contains nerve cells and glial cells.The Principal Organ SystemsThe cardiovascular system 细胞）,有些可以传导电信号（如神经细 胞）；进一步进化的细胞能够分泌不同物质

20、如荷尔蒙 （如内分泌细胞） 或酶；胚胎发育 过程中,分化的过程由于许多不同细胞来 源于受精卵而再次发生；大多数组织包含有不同的细胞类型；比如,血液中含红细胞,白细胞和血小板；红细胞运输全身的氧气；白细胞在抵抗感 染时起重要作用,血小板是血液凝集过程 中重要的成分；结缔组织有多种不同类型,但有一个共同特点,即细胞分布在丰富的 细胞外基质中；神经组织含神经细胞和神The cells of large multicellular animals cannot derive the oxygen and 经胶质细胞；nutrients they need directly from the exter

21、nal environment. The oxygen 主要的器官系统and nutrients must be transported to the cells. This is one of the principal functions of the blood, which circulates within blood vessels by virtue of 心血管系统the pumping action of the heart. The heart, blood vessels, and associated tissues form the cardiovascular sy

22、stem.The heart consists of four chambers, two atria and two ventricles, which form a pair of pumps arranged side by side. The right ventricle 大型多细胞动物体的细胞不能从外界 环境中猎取直接所需的氧气和养分物质；这些氧气和养分物质必需转运到细胞；这 是血液的主要功能之一,血液凭借心脏的pumps deoxygenated blood to the lungs where it absorbs oxygen from the 泵血作用在血管内流淌循环；心脏

23、、血管和air, while the left ventricle pumps oxygenated blood returning from the lungs to the rest of body to supply the tissues. Physiologists are concerned with establishing the factors responsible for the heartbeat, how the heart pumps the blood around the circulation, and how it is distributed to per

24、fuse the tissues according to their needs. Fluid exchanged between the blood plasma and the tissues passes into the lymphatic system, which eventually drains back into the blood.The respiratory system The energy required for performing the various activities of the body 结缔组织组成了心血管系统；心脏包括四个腔,两个心房和两个心

25、 室构成了一对并排存在的泵；右心室将脱 氧的血液泵至肺中,肺中的血液吸取空气 中的氧气,而左心室把从肺回流来的有氧 血液泵出至身体其它部位,供应给各组织；生理学家争论促使心脏跳动的因素,心脏 如何泵送血液使其循环,心脏如何依据各 组织所需支配血液；血浆和组织间的流淌 液体交换流入淋巴系统,最终回流到血液is ultimately derived from respiration. This process involves the oxidation of foodstuffs to release the energy they contain. The oxygen needed for

26、this process is absorbed from the air in the lungs and carried to the tissues 中；呼吸系统by the blood. The carbon dioxide produced by the respiratory activity of 机体进行各项活动所需的能量最终来the tissues is carried to the lungs by the blood in the pulmonary artery 源于呼吸； 这一过程包括食物 （主要是糖类where it is excreted in the expir

27、ed air. The basic questions to be answered 和脂肪） 的氧化, 释放它们所含的能量；这include the following: How is the air moved in and out of the lungs. How 一过程中, 氧气来自于肺中的空气,经由血is the volume of air breathed adjusted to meet the requirements of the body. What limits the rate of oxygen uptake in the lungs.The digestive s

28、ystem The nutrients needed by the body are derived from the diet. Food is 液到达全身各组织；组织呼吸活动中释放 的二氧化碳由肺动脉中的血液运输至肺,然后呼气排出体外；需回答的基本问题如 下：空气是如何进出肺的？呼吸的空气量 如何适应机体所需？限制肺吸取氧气频率taken in by the mouth and broken down into its component parts by enzymes in the gastrointestinal tract. The digestive products are t

29、hen absorbed into the blood across the wall of the intestine and pass to the liver 的因素是什么？消化系统via the portal vein. The liver makes nutrients available to the tissues both for their growth and repair and for the production of energy. In the case of the digestive system, key physiological questions ar

30、e: How is food 机体所需养分物质来源于饮食；食物 经口腔进入体内,在胃肠道内经酶将其分 解成小分子物质；这些消化物通过肠壁吸ingested. How is it broken down and digested. How are the individual 收入血液, 通过门静脉进入肝脏；经肝脏作nutrients absorbed. How is the food moved through the gut. How are the indigestible remains eliminated from the body.The kidneys and urinary t

31、ract The chief function of the kidneys is to control the composition of the extracellular fluid. In the course of this process, they also eliminate non-用后,这些养分物质能够中意组织生长修 复及能量需求； 在消化系统部分, 重要的生 理学问题是：食物是如何消化的？食物如 何被个体分解消化？个体养分物质如何吸 收？食物如何在肠内转运的？未消化的残 留如何从体内排出？volatile waste products from the blood. T

32、o perform these functions, the kidneys produce urine of variable composition which is temporarily stored 泌尿系统in the bladder before voiding. The key physiological questions in this case are: how do the kidneys regulate the composition of the blood. How do they eliminate toxic waste. How do they respo

33、nd to stresses such as dehydration. What mechanisms allow the storage and elimination of the 肾脏主要功能是把握细胞外液体的形 成；在这一过程中, 肾脏也会把不行挥发的 废物排出去；为行使这一功能,在排出之 前,肾脏产生含有各种成分的尿液并将其urine. 暂时储存在膀胱中；这一部分主要的生理The reproductive system Reproduction is one of the fundamental characteristics of living organisms. The gon

34、ads produce specialized sex cells known as gametes. 学问题是：肾脏如何调剂血液中的成分？如何排出有毒废物？如何应对像脱水这样 的应激反应？以及尿液可以储备和排出体 外的机制是什么？At the core of sexual reproduction is the creation and fusion of the male and female gametes, the sperm and ova eggs, with the result that the 生殖系统genetic characteristics of two separa

35、te individuals are mixed to produce 生殖是活生物体的一个基本特点；生offspring that differ genetically from their parents.殖腺产生特地的性细胞,被称为配子； 性生The musculoskeletal system This consists of the bones of the skeleton, skeletal muscles, joints, 殖的核心是雌雄配子即精子和卵子的产生 和融合,因此两个独立个体的基因特点融 合而产生一个基因上与双亲不同的后代；and their associated t

36、issues. Its primary function is to provide a means of movement, which is required for locomotion, for the maintenance of 运动系统posture, and for breathing. It also provides physical support for the internal organs. Here the mechanism of muscle contraction is a central issue. The 这一系统由骨、 骨骼肌、关节和它们的 相关组织

37、组成；其主要功能是供应运动需endocrine and nervous systems.要,保护姿势及呼吸运动；它也为内脏器官The endocrine and nervous systems The activities of the different organ systems need to be coordinated and regulated so that they act together to meet the needs of the body. Two coordinating systems have evolved: the nervous system and t

38、he endocrine 供应物理支持； 这一部分, 肌肉收缩机制是 主要问题；内分泌系统和神经系统不同器官系统的活动需要协作和调system. The nervous system uses electrical signals to transmit information 节,以便共同作用中意机体需要；人体有两very rapidly to specific cells. Thus the nerves pass electrical signals to the 大调剂系统： 神经系统和内分泌系统；神经skeletal muscles to control their contract

39、ion. The endocrine system secretes chemical agents, hormones, which travel in the bloodstream to 系统通过电信号快速将信息传导给特定细 胞；这样神经将电信号传递给骨骼肌以控the cells upon which they exert a regulatory effect. Hormones play a major 制收缩；内分泌系统分泌化学物质激素；role in the regulation of many different organs and are particularly impo

40、rtant in the regulation of the menstrual cycle and other aspects of 激素通过血流到达施与调剂作用的细胞；激素在许多不同器官中起着重要作用,在reproduction. 月经期调剂和其它生殖方面特殊重要；The immune system provides the bodys defenses against infection 免疫系统通过杀死入侵的有机体,清both by killing invading organisms and by eliminating diseased or 除致病或损耗细胞为机体供应防范功能；d

41、amaged cells. 虽然争论各器官如何行使功能很有益Although it is helpful to study how each organ performs its functions, it is essential to recognize that the activity of the body as a whole is 处,但我们必需熟识到机体作为一个整体 所做的活动依靠于各器官系统间错综复杂dependent on the intricate interactions between the various organ systems. 的相互作用； 假如一部分无法

42、正常工作,全If one part fails, the consequences are found in other organ systems 身其它器官系统也会受到影响；例如,假如throughout the whole body. For example, if the kidneys begin to fail, the 肾脏显现问题, 内部环境的调剂受损,结果regulation of the internal environment is impaired which in turn leads to 导致其它器官系统功能紊乱；disorders of function els

43、ewhere. Homeostasis稳态 各种复杂机制共同作用调剂细胞外液Complex mechanisms are at work to regulate the composition of the extracellular fluid and individual cells have their own mechanisms for 的形成,不同个体细胞有自身机制调剂内 在组成成分；尽管外界环境和动物活动不regulating their internal composition. The regulatory mechanisms 停变化,调剂机制保护着体内环境的稳固；stab

44、ilize the internal environment despite variations in both the external world and the activity of the animal. The process of stabilization of the internal environment is called homeostasis and is essential if the cells of 内部环境的稳固被称为稳态,它是机体能 够正常发挥作用所必需的；例如,心脏的跳动依靠于心肌细胞有the body are to function normall

45、y.节律的收缩； 这一活动依靠于电信号,而电Taking one example, the beating of the heart depends on the rhythmical contractions of cardiac muscle cells. This activity depends on 信号反过来依靠存在于细胞外和细胞内液 体中钠和钾离子的浓度；假如细胞外液中electrical signals which, in turn, depend on the concentration of sodium 钾离子过多, 心肌细胞兴奋性增强,可能出and potassium

46、ions in the extracellular and intracellular fluids. If there is an excess of potassium in the extracellular fluid, the cardiac muscle cells 现不规律的收缩； 因此,要保护心脏正常跳 动,细胞外液中钾离子的浓度就必需把握become too excitable and may contract at inappropriate times rather than 在确定范畴内；in a coordinated manner. Consequently, th

47、e concentration of potassium in the extracellular fluid must be kept within a narrow range if the heart is to 机体如何调剂物质成分beat normally.平稳的概念1 千克How Does The Body Regulate Its Own Composition.一天中,一个成人需要消耗约The concept of balance 食物, 23 升液体； 以一个月运算, 这相当 于约 30 千克食物, 6090 升液体；然而,In the course of a day, an

48、 adult consumes approximately 1 kg of food 一般来说, 机体体重是基本不变的；这类个and drinks 23 liters of fluid. In a month, this is equivalent to around 30 kg of food and 6090 liters of fluid. Yet, in general, body weight remains remarkably constant. Such individuals are said to be in balance; the intake of food and

49、drink matches the amounts used to generate energy for normal 体可以说处于平稳状态；食物和液体的摄 入量相当于正常机体活动消耗的能量加上 尿液和粪便中丢失的能量；在一些情形下,如饥饿状态,摄入量与机体所需量并不相bodily activities plus the losses in urine and feces. In some circumstances, 当,肌组织断裂, 供应葡萄糖产生能量；蛋such as starvation, intake does not match the needs of the body and

50、 muscle tissue is broken down to provide glucose for the generation of energy. Here, the intake of protein is less than the rate of breakdown and the 白质的摄入低于肌组织断裂的速度,机体 处于负氮平稳； 同样地, 假如机体组织正处 于生长期, 如生长期的儿童, 孕妇和早期训individual is said to have a negative nitrogen balance. Equally, if the body 练阶段的运动员,那么蛋

51、白质的日常摄入tissues are being built up, as is the case for growing children, pregnant 量比正常机体所需要的多；相反,此时个体women and athletes in the early stages of training, the daily intake of protein is greater than the normal body turnover and the individual is in positive nitrogen balance.This concept of balance can

52、be applied to any of the body constituents including water and salt and is important in considering how the body regulates its own composition. Intake must match requirements and any excess must be excreted for balance to be maintained. Additionally, for each chemical constituent of the body there i

53、s a desirable concentration range, which the control mechanisms are adapted to maintain. For example, the concentration of glucose in the plasma is about 45mmol/L 处于 正氮 平稳；平稳的概念可以应用到机体的任何构 成成分上, 包括水和盐, 而且平稳在机体调 节其自身成分上是特殊重要的；摄入必需 等于所需, 为保护机体平稳, 任何余外的能 量都必需排出； 此外,由于机体的每种化学 成分都有一个可取的浓度范畴,把握机制 保护这个范畴；

54、例如,两餐间血糖浓度大约 为 45mmol/L ；进食后不久, 血糖含量超过 这一范畴,刺激胰腺分泌胰岛素,降低浓between meals. Shortly after a meal, plasma glucose rises above this level 度；随着葡萄糖浓度的下降,胰岛素分泌减and this stimulates the secretion of the hormone insulin by the pancreas, which acts to bring the concentration down. As the concentration of 少；在此情形下

55、, 循环胰岛素水平的转变都 是为了使血浆中的葡萄糖保护在一个合适glucose falls, so does the secretion of insulin. In each case, the changes in 的范畴内； 这种调剂称为负反馈机制；在胰the circulating level of insulin act to maintain the plasma glucose at an 岛素分泌期间,葡萄糖像肝糖原或脂肪一appropriate level. This type of regulation is known as negative feedback. 样被储存

56、；During the period of insulin secretion, the glucose is being stored as either glycogen or fat.负反馈调剂是在机体显现紊乱时,将 一些变量把握在限定范畴内的一个把握系A negative feedback loop is a control system that acts to maintain the 统；虽然上面的例子讲到血糖,但这一基本level of some variable within a given range following a disturbance. Although th

57、e example given above refers to plasma glucose, the basic principle can be applied to other physiological variables such as body 原就可以应用到其它生理变量中如体温、血压和血浆的渗透浓度；负反馈调剂需要 一种能对不确定的变量做出反应而对其它temperature, blood pressure, and the osmolality of the plasma. A negative 生理变量不应答的传感器；因此,渗透压感feedback loop requires

58、a sensor of some kind that responds to the variable in question but not to other physiological variables. Thus an osmoreceptor 受器应当能对机体体液渗透的变化而不是 体温存血压的变化产生应答；感受器传递should respond to changes in osmolality of the body fluids but not to 的信息必需和理想水平（系统的调定点） 以changes in body temperature or blood pressure.

59、 the information from the 比较者的身份, 以某种方式进行比较；假如sensor must be compared in some way with the desired level by some form of comparator. if the two do not match ,an error signal is transmitted to an effector, a system that can act to restore the variable to its desired level .these features of negative

60、feedback can be appreciated by examining a simple heating system .the controlled variable is room temperature, 两者不相符,一个错误信号就会传递给效 应器,效应器是一种能使变量保持在理想 水平的系统；负反馈的这些特点可以通过 检测一种简洁的加热系统来懂得；被把握 的变量是室温,它可以由一个温度计检测which is sensed by a thermostat. the effector is a heater of some kind .when 到,效应器是一种加热器；当室温降低到