1、.wd.wd.wd.Chapter 1 Passage 1 Human BodyIn this passage you will learn:1. Classification of organ systems2. Structure and function of each organ system3. Associated medical terms To understand the human body it is necessary to understand how its parts are put together and how they function. The stud

2、y of the bodys structure is called anatomy; the study of the bodys function is known as physiology. Other studies of human body include biology, cytology, embryology, histology, endocrinology, hematology, immunology, psychology etc.了解人體各局部的組成及其功能，對于認識人體是必需的。研究人體構造的科學叫解剖學；研究人體功能的科學叫生理學。其他研究人體的科學包括生物學

3、、細胞學、胚胎學、組織學、內分泌學、血液學、遺傳學、免疫學、心理學等等。 Anatomists find it useful to divide the human body into ten systems, that is, the skeletal system, the muscular system, the circulatory system, the respiratory system, the digestive system, the urinary system, the endocrine system, the nervous system, the reprodu

4、ctive system and the skin. The principal parts of each of these systems are described in this article.解剖學家發(fā)現(xiàn)把整個人體分成骨骼、肌肉、循環(huán)、呼吸、消化、泌尿、內分泌、神經、生殖系統(tǒng)以及感覺器官的做法是很有幫助的。本文描繪并闡述了各系統(tǒng)的主要局部。The skeletal system is made of bones, joints between bones, and cartilage. Its function is to provide support and protectio

5、n for the soft tissues and the organs of the body and to provide points of attachment for the muscles that move the body. There are 206 bones in the human skeleton. They have various shapes - long, short, cube - shaped, flat, and irregular. Many of the long bones have an interior space that is fille

6、d with bone marrow, where blood cells are made.骨骼系統(tǒng)由骨、關節(jié)以及軟骨組成。它對軟組織及人體器官起到支持和保護作用，并牽動骨胳肌，引起各種運動。人體有206根骨頭。骨形態(tài)不一，有長的、短、立方的、扁的及不規(guī)那么的。許多長骨里有一個內層間隙，里面充填著骨髓，這即是血細胞的制造場所。A joint is where bones are joined together. The connection can be so close that no movement is possible, as is the case in the skull. O

7、ther kinds of joints permit movement: either back and forth in one plane - as with the hinge joint of the elbow - or movement around a single axis - as with the pivot joint that permits the head to rotate. A wide range of movement is possible when the ball - shaped end of one bone fits into a socket

8、 at the end of another bone, as they do in the shoulder and hip joints. 關節(jié)把骨與骨連接起來。顱骨不能運動，是由于骨與骨之間的連接太嚴密。但其它的關節(jié)可允許活動，如一個平面上的前后屈伸運動，如肘關節(jié)；或是繞軸心旋轉運動，如樞軸點允許頭部轉動。如果一根骨的球形末端插入另一根骨的臼槽里，大輻度的運動如肩關節(jié)、髖關節(jié)即成為可能。Cartilage is a more flexible material than bone. It serves as a protective, cushioning layer where bon

9、es come together. It also connects the ribs to the breastbone and provides a structural base for the nose and the external ear. An infants skeleton is made of cartilage that is gradually replaced by bone as the infant grows into an adult.軟骨是一種比一般骨更具韌性的物質。它是骨連結的保護、緩沖層。它把肋骨與胸骨連結起來，也是鼻腔與內耳的構造根基。一個嬰兒的骨骼

10、就是由軟骨組成，然后不斷生長、骨化，使嬰兒長大成人。The muscular system allows the body to move, and its contractions produce heat, which helps maintain a constant body temperature. Striated muscles can be consciously controlled. The ends of these muscles are attached to different bones by connective tissue bands so that whe

11、n the muscle contracts, one bone moves in relation to the other. This makes it possible to move the whole body, as when walking, or to move just one part of the body, as when bending a finger. Contractions of the heart and smooth muscles are not under conscious control. Smooth muscles are found in t

12、he walls of organs such as the stomach and the intestines and serve to move the contents of these organs through the body.肌肉系統(tǒng)使軀體運動，肌肉收縮產生的熱有助于維持一個恒定的體溫。人體能夠有意識地控制條紋肌。結締組織使肌肉末端附著于不同的骨面上，所以當肌肉收縮時，兩骨彼此靠近而產生運動。這也就使整個人體可以運動起來，如走路，運動軀體某個部位，如彎曲手指。心臟收縮和平滑肌收縮就不是被意識所控制的。器官壁內層的平滑肌，如胃腸壁的平滑肌把胃腸中的物質運送到全身。The cir

13、culatory system. All parts of the body must have nourishment and oxygen in order to function and grow, and their waste products must be removed before they accumulate and poison the body. The circulatory system distributes needed materials and removes unneeded ones. It is made up of the heart, blood

14、 vessels, and blood, which together make up the cardiovascular system. The blood is also part of the bodys defense system. It has antibodies and white blood cells that protect the body against foreign invaders. 循環(huán)系統(tǒng)：機體的所有局部需要營養(yǎng)物質和氧氣來使之發(fā)揮功能和生長，也需要在這些器官所產生的廢物積聚而危害生命之前將其排除。循環(huán)系統(tǒng)運送有用物質，排泄廢物。心血管系統(tǒng)是循環(huán)系統(tǒng)的組成

15、之一；心血管系統(tǒng)包括心臟、血管及血液。血液也是機體防御系統(tǒng)的一個局部，血液中有抗體及白細胞來防止機體受到外來的侵襲。 The heart is a muscle that is divided into two nearly identical halves: one half receives blood from the lungs and sends it to the rest of the body, the other half sends blood that has traveled through the body back to the lungs. When the he

16、art muscle contracts, the blood is forced out into arteries and enters small capillaries. Blood returns to the heart through veins. 心臟是一塊被分為幾乎對等兩半的肌肉。一半吸收來自肺部的血液，并將血液運送到機體的其余部位，另一半使流經全身的血液回流人肺。心臟收縮時，動脈把全身血液輸送到毛細血管。靜脈輸送血液返回心臟。 Also functioning in circulation is the lymphatic system. Some of the fluid

17、 that surrounds cells does not reenter the blood vessels directly. This fluid, called lymph, returns to the heart by way of another system of channels - the lymph vessels. Lymph nodes along these vessels filter the fluid before it reenters the blood. The spleen is a large lymphatic organ that filter

18、s the blood. 淋巴系統(tǒng)也是循環(huán)系統(tǒng)的一個組成局部。一些細胞周圍的體液不是直接回流入血管通道，這種體液叫淋巴液，它是流經另一個管道系統(tǒng)淋巴管而回流人心臟。沿淋巴管的淋巴結將淋巴液過濾，過濾后再回流人血液。脾是一個過濾血液的大淋巴器官。 The respiratory system takes in oxygen from the air and expels carbon dioxide and water vapor. Air enters the nose and mouth and travels through the larynx, and trachea. The tra

19、chea divides to enter each of the two lungs and then divides more than 20 times to form a very large number of small air spaces. Oxygen from the air enters the blood through capillaries in the walls of these air spaces, and the blood release carbon dioxide into the air spaces to be exhaled. 呼吸系統(tǒng)從空氣中

20、攝取氧氣，并將二氧化碳、水蒸氣排出體外?？諝饨洷乔?、口腔人喉管、氣管。氣管分成左右支氣管，各連結左右肺，左右支氣管再分枝20屢次，在終端形成大量微小的肺泡。從空氣攝取的氧氣流經這些肺泡壁內的毛細血管流入血液，血液再經肺泡把釋放出的二氧化碳排出體外。 The digestive system consists of a tube extending from the mouth to the anus. In it, food and fluids are taken in, moved through the body, and broken down into small molecules

21、 that are absorbed into the circulatory system. This breakdown, known as digestion, is both a mechanical and a chemical process.消化系統(tǒng)是一個從口腔直到肛門的管道。食物和液體在消化道里被吸收，在腸道里移動時，被分解成小分子物質后再進入循環(huán)系統(tǒng)。這種分解，即消化，是一個機械過程，也是一個化學過程。 Food enters through the mouth, where chewing and saliva start to break it up and make i

22、t easier to swallow. Next, the food travels down through the esophagus to the stomach. Contractions of the stomachs muscular wall continue to break down the food mechanically, and chemical digestion continues when acid and enzymes are secreted into the stomach cavity. 食物進入口腔里，咀嚼和唾液開場將食物粉碎，使之便于吞咽。接著，

23、食物經食管人胃。胃肌壁的收縮繼續(xù)機械化地分解食物，而當酸和酶分泌入胃腔時，化學性消化開場。The liquified food gradually passes into the small intestine. In the first part of the small intestine, called the duodenum, enzymes from the pancreas are added. These enzymes complete the chemical breakdown of the food. The digestion of fat is aided by b

24、ile, which is made in the liver and stored in the gall bladder. The small intestine of an adult is about 21 feet (6.4 meters) long. Most of its length is devoted to absorbing the nutrients released during these digestive activities. 液體化食物逐漸進入小腸。小腸的起始局部叫十二指腸，胰腺分泌的酶輔助食物消化。這些酶完成食物的化學分解。肝臟分泌的膽汁貯存在膽囊內，膽汁

25、有助于脂肪消化。一個成年人的小腸有21英尺6.4米長。小腸的大局部腸段用來吸收消化過程中釋放的營養(yǎng)物質。 The liquid remainder of the food enters the large intestine, or colon, which is about 12 feet (3.7 meters) long. It is more than twice as wide as the small intestine. In the large intestine most of the fluid is absorbed, and the relatively dry res

26、idues are expelled. 液狀的剩余食物進入大腸，或結腸，它大約有12英尺3.7米長。大腸是小腸的兩倍多寬。大局部液體在大腸內被吸收，相對干化的剩余物被排出體外。 The urinary system maintains normal levels of water and of certain small molecules such as sodium and potassium in the body. It does this by passing blood through the kidneys, two efficient filtering organs that

27、 get rid of any excess of various molecules and conserve those molecules that are in short supply. 泌尿系統(tǒng)維持水分及體內某些小分子物質，如鈉、鉀的正常水平。身體是通過讓腎過濾血液來做到這一點的。腎是兩個有效的過濾器官，它濾出各種多余的小分子物質，保存那些供應缺乏的小分子物質。 The fluid that leaves the kidneys, known as urine, travels through a tube called the ureter to the bladder. The

28、 bladder holds the urine until it is voided from the body through another tube, the urethra. 從腎流出的液體，即尿，通過輸尿管人膀胱。膀胱起貯存尿液的作用，直到尿經膀胱另一端的管道排出。 The endocrine system. The two systems that control body activities are the endocrine system and the nervous system. The former exerts its control by means of ch

29、emical messengers called hormones. Hormones are produced by a variety of endocrine glands, which release the hormones directly into the blood stream. 內分泌系統(tǒng)。內分泌和神經是調控機體活動的兩個系統(tǒng)，前者依靠其化學信使激素發(fā)揮作用。激素是由各種內分泌腺體制造，并直接被釋放入血流 A major gland is the pituitary, which is located under the brain in the middle of the

30、 head. It produces at least eight hormones, which affect growth, kidney function, and development of the sex organs. Because some of the pituitarys hormones stimulate other glands to produce their own hormones, the pituitary called the master gland. 腦垂體是一個主要腺體，它位于頭中部腦下方。它至少分泌八種激素，這些激素對人體生長、肝功能及性器官發(fā)育

31、有影響。因為腦垂體分泌的一些激素促進其他腺體分泌激素，所以腦垂體是主要腺體。 Another gland, the thyroid, is located between the collar bones. Its hormone controls the rate of the bodys metabolism. The sex organs (ovaries end testes) make the sex cells and also make hormones that control certain characteristics of males and females. Loca

32、ted on top of each kidney is the adrenal gland, which produces cortisone and adrenaline. The pancreas produces not only digestive enzymes but also 3 insulin and glucagon, which control the bodys use of sugar and starches. 另一個腺體，甲狀腺，位于鎖骨之間。甲狀腺激素調控著機體新陳代謝的速度。性器官卵巢、睪丸分泌性細胞和性激素，這些激素控制著男性和女性的某些特征。每邊腎上方是腎

33、上腺，它分泌可的松和腎上腺激素。胰腺不僅分泌消化酶，而且分泌胰島素和高血糖素，這兩種激素控制機體的糖分及淀粉的消耗。 The nervous system. The brain, the spinal cord and the nerve - also controls body activities. The lower parts of the brain control basic functions such as breathing and heart rate as well as body temperature, hunger, and thirst. Above these

34、regions are the centers for sight, sound, touch, smell, and taste, and the regions that direct voluntary muscular activities of the arms and legs. Performed here are the higher functions of integrating and processing information. 神經系統(tǒng)腦、脊髓及神經，也調控機體活動。腦的偏下部位控制著諸如呼吸、心跳、體溫、饑渴的 基本活動。而腦的偏上部位那么是視覺、聽覺、觸覺、嗅覺

35、及味覺中心，也是指揮臂、腿隨意肌肉運動的區(qū)域。神經系統(tǒng)更高級的功能是整合、處理信息。 The brain receives and sends information by means of nerves, many of which lie partly in the spinal cord. The spinal cord is protected by the spinal column. Nerves enter and leave the spinal cord at each level of the body, traveling to and from the arms, le

36、gs, and trunk. These nerves bring information from the various sense organs. The information is processed by the brain, and then messages are carried back to muscles and glands through out the body. 腦通過神經收集并傳送信息，許多神經局部地分布在脊髓里。脊髓由脊柱保護。在機體每一級，神經傳人、傳出脊髓，往返于臂、腿、軀體。這些神經輸送來自各種感覺器官的信息。信息經腦處理后輸送回全身及腺體 The r

37、eproductive system is constructed differently for males and females. The male reproductive system is responsible for producing, transporting and maintaining viable sperm (the male sex cell). It also produces the male sex hormone, testosterone, which regulates the development of a beard, pubic hair,

38、a deep voice and other bodily characteristics of the adult male. 男、女性的生殖系統(tǒng)不同。男性生殖系統(tǒng)產生、輸送、維持能存活的精子男性性細胞。它也分泌男性激素、睪酮，以此調節(jié)胡須、陰毛、深沉嗓音極其他成年男子身體發(fā)育的特征。 The female productive system is responsible for producing and transporting ova (the female sex cells), eliminating ova from the body when they are not fert

39、ilized by sperm, nourishing and providing a place for growth of an embryo when an ovum is fertilized by sperm, and nourishing a newborn child. The female reproductive system also produces the female sex hormones, estrogen and progesterone, which regulate the development of breasts and other bodily c

40、haracteristics of the mature female. 女性生殖系統(tǒng)產生、輸送卵子女性性細胞，將未受精的卵子排出體外，而當精、卵結合時，女性生殖系統(tǒng)培養(yǎng)、提供胚胎生長場所，并孕育新生兒。女性生殖系統(tǒng)也分泌女性性激素雌激素和孕酮，以此調節(jié)乳房及其他成熟女性身體發(fā)育的特征。 The skin is a complete layer that protects the inner structures of the body, and it is the largest of the bodys organs. It keeps out foreign substances and

41、 prevents excessive water evaporation. The nerves in the skin provide tactile information. The skin also helps keep the bodys temperature close to 37 C, heat is conserved by reducing blood flow through the skin or is expended by increasing blood flow and by evaporation of sweat from the skin. Hair a

42、nd nails are accessory structures of the skin. 皮膚是保護肌體內層構造的完整層，也是機體的最大器官。皮膚防御外來侵襲，防止過多水分蒸發(fā)。皮膚上的神經提供觸覺信息。皮膚也能將體溫維持到98.6華氏度約37攝氏度。通過皮膚的血流量降低時，熱量就被儲存起來，通過皮膚的血流增加及汗液蒸發(fā)時，熱量就散發(fā)。頭發(fā)及指甲是皮膚的附屬構造。 Cells and Tissues細胞與組織In this passage, you will learn:1.Human body systems as a whole 2.Vital parts of a cell 3.Fo

43、ur kinds of tissuesCells are organized into tissues, and tissues are arranged into organs, which in turn are grouped into systems. Each body system serves its specific functions. Bear in mind however that the body functions as a wholeno system is independent of the others. They work together to main

44、tain the bodys state of internal stability, termed homeostasis. Now lets begin our discussion with cells, the smallest unit of living matter that can exist by itself. 細胞構成組織，組織構成器官，器官又進一步構成系統(tǒng)。人體的每個系統(tǒng)都有其特定功能，但是，請記住這里:機體是作為一個整體來發(fā)揮作用的，沒有哪個系統(tǒng)能夠獨立于其他系統(tǒng)而存在，是整體系統(tǒng)共同作用保持了機體內部的穩(wěn)定狀態(tài)，即體內平衡。現(xiàn)在，我們先討論細胞能獨立存在活性物質的最

45、小單位。The body can be studied from its simplest to its most complex level, beginning with the cell. All body functions result from the activities of billions of the specialized cells. Some plants and animals consist of only a single cell. Others are composed of many billions of cells. 從細胞開場，我們能夠從最簡單到最

46、復雜的水平來研究機體。所有人體的功能都來自億萬個特定細胞活動，有的動植物僅由一個細胞構成，其他生物那么由億萬個細胞構成。Cells exist in a variety of shapes and sizes. They may, for example, be cube-shaped or flat. Scientists who study cells have determined that a single cell may be as large as a tennis ball or so small that thousands would fit on the point of

47、 a needle. The yolk of a hens egg is actually a very large cell. By contrast, bacteriaeach one of which is a tiny cellare among the smallest cells. Regardless of its shape or size, every cell contains the “machinery needed to maintain life. While normally cells function with great efficiency, they a

48、re subject to various disorders that result in disease. 細胞有很多種形狀和大小。列如：有可能是立方形或扁形的。科學家的研究發(fā)現(xiàn)單獨一個細胞可以像網球一樣的大小，或小到幾千個細胞才能剛好填滿針頭。雞的蛋黃是一個非常大的單細胞。微小的細菌呢算是最小的細胞。不管是細胞大小或形狀的不同，每個細胞都有“需要存活的機制。對每個正常的細胞，有效力的細胞，都存在許多問題，能導致疾病。The size of cells is usually measured in microns. A micron is a millionth of a meter, a

49、nd about 25,000 microns equal one inch. The smallest bacteria are about 0.2 micron in diameter. The average cell in the human bodyabout ten microns in diameteris a speck barely visible without the aid of a microscope. 細胞的大小是以“微米為長度單位。微米是一米的一百萬分之一，25000微米等于一寸。最小的細菌的圓徑是0.2微米。人體正常細胞的評價圓徑約十微米，肉眼勉強可以看得到，

50、不需要顯微鏡的幫助。The study of cells is the branch of biology called cytology. The science that deals with cells on the smallest structural and functional level is called molecular biology. 研究關于“細胞是生物學的分支，成為細胞生物學。在最微小水平針對細胞的構造及功能的研究成為分子生物學。All cells consist of protoplasm, the “l(fā)iving jelly. The protoplasm o

51、f a typical cell forms three vital partsthe cell membrane, the cytoplasm, and the nucleus. The membrane encloses the other cell structures. Much of the chemical work of the cell is done in the cytoplasm, which surrounds the nucleus. The nucleus, enclosed by its own membrane, is the control center of

52、 the cell. (see Figure 1-1) 所有細胞都是以“原生質，又稱“生命膠質所形成的。典型細胞的原生質形成了三個重要局部，細胞膜、細胞質和細胞核。細胞膜圈住了細胞的其他構造。大局部的化學反響都在細胞核周圍，細胞質完成的。被自己的膜包圍的細胞核是細胞的控制中心。the cells Membrane細胞膜Cells can survive only in a liquid medium that brings in food and carries away waste. For one-celled organisms this fluid is an external bod

53、y of waterthe ocean, a lake, or a stream. For many-celled plants and animals, however, the medium is part of the organismin plants, the sap; in animals, the blood. 細胞只能存活在能供養(yǎng)分又能排除廢物的液體媒介中。對單細胞生物來說，這就是細胞外的液體，如：大海里、河里或水流中。在對多細胞生物而言，這種媒介就是生物體的一局部，植物以汁液的形式，動物以血液的形式。The cell membrane is semipermeable, or

54、 differentially permeablesome substances can pass through it, but others cannot. This characteristic enables the cell to admit useful substances and to reject harmful substances from the surrounding fluid as well as to force out, or excrete waste products into the fluid. 細胞膜是半滲透性或區(qū)別性的滲透膜，即某些物質能滲透。這個

55、特殊性使細胞對細胞周圍只吸收了需要的物質而排除掉有害的物質，包括細胞內的廢物通過液體化后排出細胞外。The cell membrane is an extremely thin but tough band of protein and phospholipid molecules. Phospholipids are chemicals similar to stored fat. On the evidence of electron micrographs, biologistsbelieve that it has pores through which certain small m

56、olecules pass intact. Substances probably pass through the cell membrane in several ways. Small chambers located on the cell membrane called caveolae gather chemical signals and channel them into the cells. The caveolae may also help distribute proteins throughout the cell. Large molecules enter the

57、 cell by a process called diffusion, in which they may be dissolved by substances in the cell membrane. They can then through the membrane without difficulty. Some cells take in large molecules by means of pinocytosis. In this process, the cell membrane forms a pocket around large molecules floating

58、 against it. The molecule-and-fluid-filled pocket then breadsloose from the membrane to become a bubblelike vacuole, and the vacuole then drifts into the cytoplasm. Finally, the vacuole wall breaks up and the molecules are released into the cytoplasm. 細胞膜是一種非常薄但確以很穩(wěn)固的蛋白磷脂膜形成。磷脂是一種類似于儲存的脂肪的蛋白物質。通過電子顯

59、微鏡，生物學家相信細胞膜有孔，使較小的物質完全可以通過。物質可通過多種方式從細胞膜進入。細胞膜上的構造，稱“小穴，可承受化學信號再傳到細胞內。小穴還可能參于細胞蛋白的分配。大的分子可通過“滲濾進入細胞內，或被細胞膜內體分解，使它們更容易的進入細胞內。有些細胞可通過“胞飲方式吞飲較大的物質。這個過程是通過細胞膜在大物質形成了“帶把它包圍著，將它以泡狀的“液泡引入細胞質，最后包圍解散，大物質成功的進入細胞內。The cytoplasm細胞質The cytoplasm is mainly water. Its water content varies from a minimum of about

60、65 percent to a maximum of about 95 percent. The solids in the cytoplasm include granular proteins, carbohydrates, droplets of fat, and pigments. The cytoplasm is thus a colloidal system. 細胞質主要成分是“水。水分含量有百分之65到最高，百分之95。細胞質內的固體包括蛋白顆粒、碳水化合物、脂肪小滴和色素。細胞質是膠體性的。The cytoplasm may be either watery or syrupy