药学英语第五版原文翻译Word文档下载推荐.docx

1、一个生物体的各部分起着什么作用可通过实验观察得知。尽管我们对志愿者进行了许多重要的生理调查，但是实验条件需要精确控制，所以我们当前大多生理知识还是源于对其它动物如青蛙，兔子，猫和狗等的研究。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。通过这种方法，我们获得了大量的知识，从而让我们对人类生理学有了更深入的了解，为我们有效治疗许多疾病提供了一个坚实的基础。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皮组织，结缔组织，神经组织和肌组织，每类组织都有各自的特征。许多结缔组织中细胞量相对较少，但是有大量的细胞外基质。相比而言，光滑的肌

2、组织由大量密密麻麻each with its own characteristics.Many connective tissues have relatively few cells but have an extensive extracellular matrix.In contrast,smooth muscle consists of densely packed layers of muscle cells linked together via specific cell junctions.Organs such as the brain,the heart,the lungs

3、,the intestines,and the liver are formed by the aggregation of different kinds of tissues.The organs are themselves parts of distinct 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 res

4、piratory system;the skeleton and skeletal muscles form the musculoskeletal system;the brain,spinal cord,autonomic nerves and 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

5、are bounded by a limiting membrane,the plasma membrane.Secondly,they have the ability to break down large molecules to smaller ones to liberate energy for their activities.Thirdly,at some point in their life history,they possess a nucleus which contains genetic information in the form of deoxyribonu

6、cleic acid（DNA）.Living cells continually transform materials.They break down glucose and fats to provide energy for other activities such as motility and the synthesis of proteins for growth and repair.These chemical changes are collectively called metabolism.The breakdown of large molecules to smal

7、ler ones is called catabolism and the synthesis of large molecules from smaller ones 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 d

8、eveloped the ability to secrete different substances such as hormones or enzymes.During embryological development,this process of differentiation is re-enacted as many different types of cell are formed from the fertilized egg.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聚集而成。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

9、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周围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，但是它们有某些共同的特征。第一，它们由限制膜包被，即细胞质膜；第二，细胞有把大分子分解为小分子来释放活动所需能量的能力；第三，在生命过程中某个阶段，细胞体内存在一个以脱氧核糖核酸（DNA）形式包含基因信息的细胞核。活体细胞不断转化物质。它们为其它活动提供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

10、过程中不断分化进行不同的功能活动。有些细胞具有收缩能力（如肌细胞），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，分化的过程由于很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。白细胞在抵御感染时起重要作用，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，但有一个共同特征，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经胶质细胞。Most tissues contain a mixture of cell types.For exam

11、ple,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 clotting.There are a number of different types of connective tissue

12、but all are characterized by having cells distributed within an extensive noncellular matrix.Nerve tissue contains nerve cells and glial cells.The Principal Organ Systems The cardiovascular system The cells of large multicellular animals cannot derive the oxygen and nutrients they need directly from

13、 the external environment.The oxygen 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 the pumping action of the heart.The heart,blood vessels,and associated tissues form the cardiovascular system.The

14、 heart consists of four chambers,two atria and two ventricles,which form a pair of pumps arranged side by side.The right ventricle pumps deoxygenated blood to the lungs where it absorbs oxygen from the air,while the left ventricle pumps oxygenated blood returning from the lungs to the rest of body t

15、o 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 perfuse the tissues according to their needs.Fluid exchanged between the blood plasma and the tissues passes

16、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 is ultimately derived from respiration.This process involves the oxidation of foodstuffs to release the energy they contain.The oxygen ne

17、eded for this process is absorbed from the air in the lungs and carried to the tissues by the blood.The carbon dioxide produced by the respiratory activity of 主要的器官系统 心血管系统 大型多细胞动物体的细胞不能从外界环境中获取直接所需的氧气和营养物质。这些氧气和营养物质必须转运到细胞。这是血液的主要功能之一，血液凭借心脏的泵血作用在血管内流动循环。心脏、血管和结缔组织组成了心血管系统。心脏包括四个腔，两个心房和两个心室构成了一对并排存

18、在的泵。右心室将脱氧的血液泵至肺中，肺中的血液吸收空气中的氧气，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。生理学家研究促使心脏跳动的因素，心脏如何泵送血液使其循环，心脏如何根据各组织所需分配血液。血浆和组织间的流动液体交换流入淋巴系统，最终回流到血液中。呼吸系统 机体进行各项活动所需的能量最终来源于呼吸。这一过程包括食物（主要是糖类和脂肪）的氧化，释放它们所含的能量。这一过程中，氧气来自于肺中的空气，经由血液到达全身各组织。组织呼吸活动中释放的二氧化碳由肺动脉中的血液运送至肺，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

19、吸收氧气频率的因素是什么？消化系统 机体所需营养物质来源于饮食。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收入血液，通过门静脉进入肝脏。经肝脏作用后，这些营养物质能够满足组织生长修复及能量需求。在消化系统部分，重要的生理学the tissues is carried to the lungs by the blood in the pulmonary artery where it is excreted in the expired air.The basic questions to be answered include the following:Ho

20、w is the air moved in and out of the lungs?How 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 system The nutrients needed by the body are derived from the diet.Food is taken in by the mouth and broken down

21、into its component parts by enzymes in the gastrointestinal tract.The digestive products are then absorbed into the blood across the wall of the intestine and pass to the liver via the portal vein.The liver makes nutrients available to the tissues both for their growth and repair and for the product

22、ion of energy.In the case of the digestive system,key physiological questions are:How is food ingested?How is it broken down and digested?How are the individual nutrients absorbed?How is the food moved through the gut?How are the indigestible remains eliminated from the body?The kidneys and urinary

23、tract 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-volatile waste products from the blood.To perform these functions,the kidneys produce urine of variable composition which is temporarily stored in th

24、e 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 respond to stresses such as dehydration?What mechanisms allow the storage and elimination of the urine?The reproductive sys

25、tem Reproduction is one of the fundamental characteristics of living organisms.The gonads produce specialized sex cells known as gametes.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 genetic characteristics of two 问题是：食物是如何消化的？食物如何被个体分解消化？个体营养物质如何吸收？食物如何在肠内转运的？未消化的残留如何从体内排出？泌尿系统 肾脏主要功能是控制细胞外液体的形成。在这一过程中，肾脏也会把不可挥发的废物排出去。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暂时储存在膀胱中。这一部分主要的生理学问题是：肾脏如何调节血液中的成分？如何排出有毒废物？如何应对像脱水这样的应激反应？以及尿液可以存储和排出体外的机制是什么？生殖系统 生殖是活生物体