医学英语教程Chapter

1、Chapter 2Terms pertaining to the body as a wholeI. Structural Organization of the body.CellsThe cells is the fundamental unit of all living things (animal or plant). Cells are every where in the human body-every tissue, every tissue, every organ is made up of these individual units.Similarity in Cel

2、ls. Allcells are similar in that they contain a gelatinouis substance composed of water, protein, sugar, acids, fats, and various minerals. Several parts of a cell with an electron microscope. Label the structures on Figure 2-1. Throughout the book, numbers in brackets indicate that the boldfaced te

3、rm preceding it is to be used in labeling.The cell membrane not only surrounds and protects the cell, but also regulates what passes into and out of the cell.The nucleus controls the operations of the cell. It directs ce; dovosopm amd determines the structure and function of the cell.Chromosomes are

4、 rod-like structures within the necleus. All human body cells contain 23 pairs of chromosomes. Each sperm and egg cell has only 23 unpaired chromosomes. After the egg and sperm cells unite to form the embryo, each cell of the embryo, each cell of the embryo then has 46 chromosomesChromosomes contain

5、 regions called genes. These are sevveral thousand genes, in an orderly sequence, on every chromosome. Each gene is composed of a chemical called DNA. DNA regulates the activities of the cell by its sequence on each chromosome. The DNA sequence resembles a series of recipes in code. The code, when p

6、assed out of the nucleus to the rest of the cell, directs the activities of the cell, such as cell division and synthesis of proteins. Chromosomes within the necleus are analyzed in terms of their size, arrangement, and number by performing a karytype. Karyotyping of chromosomes determines whether t

7、he chromosomes are normal in number and structure. For example, obstetricians often recommend an amniocentesis for a pregnant woman so that the karyotype of the baby can be examined. Figure 2-3 shows a karyotype, or chromosome map, of a normal male. The chromosomes have been treated with chemicals s

8、o that bands can be seen.If a baby is born with an abnormal number if chromosomes, serious problems can result. In Down syndrome, the karyotype shows 47 chromosomes instead of the normal number of 46. The extra number 21 chromosome results in the development of a child with Down syndrome. Its incide

9、nce is about 1 in every 750 live births, but as the mothers age increases, the presence of the chromosomal abnormality increases. A typical Down syndrome infant is born with physical malformations that may include a small, flattened skull; a short, flat-bridged nose; wide-set, slanted eyes; and shor

10、t, broad hands and feet with a wide gap between the first and second toes. Reproductive organs are often underdeveloped, congenital heart defects are not uncommon, and some degree of mental retardation is evident.Continue labeling Figure 2-1Cytoplasm includes all the material outside the nucleus and

11、 enclosed by the membrane. It carries on the work of the cell. The cytoplasm contains: Mitochondria are small, sausage-shaped bodies that, like miniature power plants, produce energy by burning food in the presence of oxygen. During this chemical process, called catabolism, complex foods are broken

12、down into simpler substances. The catabolism of sugar and fat releases needed energy to do the work of the cell.Endoplasmic reticulum is a network of canals within the cell. These canals are a cellular tunnel system in which proteins are manufactured for use in the cell. This process of building up

13、complex materials, such as proteins, from simpler parts is called anabolism. Durining anabolism, small pieves of protein are fitted together like links in a chain to make larger proteins.The two processes, anabolism and catabolism, are known as metabolism. Metabolism is the total of the chemical pro

14、cesses occurring in a cell. If a person has a “fast metabolism,” then foods, such as sugar and fat, are thought to be used up very quickly, and energy is released. If a person has a “slow metabolism,” foods are thought to be burned slowly, and fat accumulates in cells.Study Section 1Practice spellin

15、g each, term, and know its meaning.anabolism Process of building up complex material from simple materials.catabolism Process of breaking down complex materials to form simpler substances and release energycell membrane Structure surrounding and protecting the cell. It determines what enters and lea

16、ves the cellchromosomes Rod-shaped structures in the nucleus that contain regions of DNA called genes. These are 46 chromosomes in every cell except for the egg and sperm cells, which contain only 23 individual, unpaired chromosomes.Cytoplasm All the material that is outside the nucleus and yet cont

17、ained within the cell membraneDNA Chemical found within each chromosome. Arranged like a sequence of recipes in code, it directs the activities of the cell. Endoplasmic reticulum structure within the cytoplasm. Site in which large proteins are made from smaller protein pieces. Ribosomes are found on

18、 the endoplasmic reticulumgenes regions of DNA within each chromosomekaryotype Picture of chromosomes in the nucleus of a cell. The chromosomes are arranged in numberical order to determine their number and structuremetabolism The total of the chemical processes in a cell. Itt includes both cataboli

19、sm and anabolismmitochondria Structures in the cytoplasm in which foods are burned to release energynucleus Control center of the cell. It contains chromosomes and directs the activities of the cellDifferences in Cells. Cells are different, or specialized, throughout the body to carry out their indi

20、vidual functions. For example, a muscle is long and slender and contains fibers that aid in contracting and relaxing; an epithelial cell may be square and flat to provide protection; a nerve cell may be long and have various fibrous extensions that aid in its job of carrying impulses; a fat cell con

21、tains large, empty spaces for fat storage. These are only a few of the many types of cells in the body. Figure 2-5 illustrates the different sizes and shapes of muscle, nerve, fat, and epithelial cells.TissuesA tissue is a group of similar cells working together to do a specific job. A histologist i

22、s a scientist who specializes in the study of tissues. Different types of tissues include.Epithelial Tissue, located all over the body, forms the linings of internal organs, and the outer surface of the skin covering the body. It also lines exocrine and endocrine glands. The term epithelial original

23、ly referred to the tissue above the breast nipple. Now it describes all tissue that covers the outside of the body and lines the inner surface of internal organs.Muscle Tissue. Voluntary muscle found in arms and legs and parts of the body where movement is under conscious control. Involuntary muscle

24、, found in the heart and digestive system, as well as other organs, allows movement that is not under conscious control. Cardiac muscle is a specialized type of muscle found only in the heart and can be seen beating in a 6-week-old fetus.Connective Tissue. Examples are fat, cartilage, and blood.Nerv

25、e Tissue. Nerver tissue conducts impulses all ove the body.OrgansOrgans are structures composed of several kinds of tissue. For example, an organ such as the stomach is composed of muscle tissue, nerve tissue, and glandular epithelial tissue. The medical term for internal organs is viscera. Examples

26、 of abdominal viscera are the liver, stomach, intestines, pancreas, spleen, and gallbladder.SystemsSystems are groups of organs working together to perform complex functions. For example, the mouth, esophagus, stomach, and small and large intestines are organs that do the work of the digestive syste

27、m to digest food and absorb it into the bloodstream.Examine the body systems listed below with their individual organs. Learn to spell and identify the organs in boldface.Systems. Digestive: mouth, pharynx(throat), esophagus, stomach, intestines (small and large), liver, gallbladder, pancreasUrinary

28、 or excretory: kidneys, ureters, urinary bladder, urethra. Respiratory: nose, pharynx, larynx(voice box), trachea (windpipe), bronchial tubes, lungsReproductive: female: ovaries, fallopian tubes, uterus (womb), vagina, mammary glands, bartholin gland (前庭球腺); male: testes and associated tubes, urethr

29、a, penis, prostate gland, epididymis.epididimis,. seminal vesicle 精囊腺bulbourethral gland, 尿道球腺Endocrine: thyroid gland, pituitary gland, sex glands (ovaries and testes), adrenal glands, pancreas(islets of Langerhans), parathyroid glandsNervous: brian, spinal cord, nerves, and collections of nerves.

30、Circulatory: heart, blood vessels (arteries, vains, and capillaries), inferior caval vein, superior vena cava,lymphatic vessels and nodes, spleen, thymus gland. Musculoskeletal: muscles, bones, and jointsSkin and sense organs: skin, hair, nails, sweat glands, sebaceous (oil) glands, eye, ear, nose,

31、and gongue. Study Section 2adipose tissue Collection of fat cellscartilage Flexible connective tissue attached to bone at joints. For example, it surrounds the trachea and forms part of the external ear and noseepithelial cell Skin cells that cover the external body surface and line the internal sur

32、faces of organs.Histologist Specialist in the study of tissuesLarynx Voice box; located at the upper part of the tracheaPharynx Throat. The pharynx is the common passageway for food and air.pituitary gland Endocrine gland at the base of the brainthyroid gland Endocrine gland that surrounds the trach

33、ea in the necktrachea windpipeureter One of two tubes, each leading from a single kidney to the urinary bladder. Spelling clue: Ureter has two es and there are two of themurethra Tube from the urinary bladder to the outside of the body. Spelling clue: Urethra has one e and there is only one urethrau

34、terus The womb. The organ that holds the embryo and fetus as it developsviscera Internal organsII. Body cavitiesA body cavity is a space within the body that contains internal organs. Label Figure 2-6 as you learn the names of the body cavities. Some of the important viscera contained within those c

35、arvities are listed as well.Cranial Brain, pituitary gland.Thoracic lungs, heart, esophagus, trachea, bronchial tubes, thymus gland, aorta. The thoracic cavity is divided into two smaller cavities:a. Pleural cavityspace surrounding each lung. A double-folded membrane, or pleura, lines the pleural ca

36、vity. If the pleura becomes inflamed, the pleural cavity can fill with fluid.b. Mediastinumcentrally located area outside of and between the lungs. It contains the heart, aorta, trachea, esophagus, thymus gland, bronchial tubes, and many lymph nodes.Abdominal Stomach, small and large intestines, spl

37、een, pancreas, liver, and gallbladder. The peritoneum is the double-folded membrane surrounding the abdominal cavity. The kidneys are two bean-shaped organs situated behind the abdominal cavity on either side of the backbonePelvic Portions of the small and large intestines, rectum, urinary bladder,

38、urethra, and ureters; uterus and vagina in the femaleSpinal Neves of the spinal cord The cranial and spinal cavities are considered dorsal body cavities because of their location on the back portion of the body. The thoracic, abdominal, and pelvic cavities are ventral body cavities because they are

39、on the front portion of the body. See Figure 2-6.The thoracic and abdominal cavities are separated by a muscular wall called the diaphragm. The abdominal and pelvic cavities are not separated by a muscular wall, and together they are frequently called the abdominopelvic cavity. Figures 2-9 and 2-10

40、show the abdominal and thoracic viscera from anterior and posterior views.Study Section3Practice spelling each term, and know its meaningabdominal cavity Space below the chest containing organs such as the liver, stomach, gallbladder, and intestines; also called the abdomencranial cavity Space in th

41、e head containing the brain and surrounded by the skull. Cranial means pertaining to the skulldiaphragm Muscle separating the abdominal and thoracic cavitiesdprsal (posterior) Pertaining to the backmediastinum Centrally located space between the lungspelvic cavity Space below abdomen containing port

42、ions of the intestines, rectum, urinary bladder, and reproductiveorgans. Pelvic means pertaining to the hip bone, which surrounds the pelvic cavityperitoneum Membrane surrounding the organs in the abdomenpleura A double-layered membrane surrounding each lungpleural cavity Space between the pleural m

43、embranes and surrounding each lungspinal cavity Space within the spinal column and containing the spinal cord. Also called the spinal canal.thoracic cavity Space in the chest containing the heart, lungs, bronchial tubes, trachea, esophagus, and other organsventral (anterior) Pertaining to the frontI

44、II. Abdominopelvic Regions and QuadrantsRegionsDoctors divide the abdominopelvic area into nine regions. Study the names of these regions, which are found in Figure 2-11.Hypochondriac regions: two upper right and left regions below the cartilage of the ribs that extend over the abdomenEpigastric reg

45、ion: region above the stomachLumbar regions: two middle right and left regions mear the waistUmbilical region: region of the navel or umbilicusInguinal regions: two lower right and left regions near the groin, which is the area where the legs join the truck of the body. These regions are also known

46、as illiac regions because they are near the illium, which is the upper portion of the hip bone on each side of the bodyHypogastric region: lower middle region below the umbilical regionQuadrantsThe abdominopelvic area is divided into four quadrants by drawing two imaginary lines-one horizontally and

47、 vertically through the body. Figure 2-12 shows these quadrants. You add the proper abbreviation on the line under each label on the diagram.Abdominalpelvic area is divided into four quadrants by drawing twl imaginary lines: RUQ: Contains the liver, gallbladder, part of the pancreas, parts of the sm

48、all and large intestinesLUQ: Contains the liver, stomach, spleen, part of the pancreas, parts of the small and large intestinesRLQ: ovary, right fallopian tube, appendix, right ureterLLQ: contains parts of the small and large intestines, left ovary, fallopain tube, left ureter.IV. Divisions of the b

49、ack (spinal colum)The spinal column is composed of a series of bones that extend from the neck to the tailbone. Each bone is a vertebra (plural vertigrae). Lable thedivisions of the back on Figure 2-13 as you study the followingSpinal cord: nervous tissue within the spinal cavity. Disk (disc): a pad

50、 of cartilage between vertebrae. Cervical devision: neck region C1C7Thoracic: chest region T1-T12Lumbar: Loin (waist) or flank region (between the ribs to hipbone) L1-L5Sacral: S1-S5, are fused to form one bone, the sacrumCoccygeal: the coccyx (tail bone) four fused pieces. Do not confuse the spinal

51、 column and the spinal cord. The column is bone tissue, whereas the cord is nervous tissue.The spaces between the vertebrae are identified according to the two vertebrae between which they lie; for example, L5-S1 lies between the fifth lumbar and the first sacral vertebrae. Within the space and betw

52、een vertebrae is a small pad called a disk or disc. The disk, composed of water and cartilage, is a shock absorber. Occasionally, it moves out of place and puts pressure on a nerve. This is a slipped disk, which causes back pain.Study Section 4Practice spelling each term, and know its meaningABDOMIN

53、OPELVIC REGIONShypochodiriac Upper right and left regions beneath the ribs.Epigastric Upper middle region above the stomachLumbar middle right and left regions near the waistUmbilical central region near the navelInguinal Lower right and left regions near the groin. Also called iliac regions.Hypogas

54、tric Lower middle region below the umbilical regionABDOMINOPELVIC QUADRANTSRUQ Right upper quadrantLUQ Left upper quadrantRLQ Right lower quadrantLLQ Left lower quadrantDIVISIONS OF THE BACKcervical Neck regionthoracic Chest regionlumbar Loin regionsacral Region of the sacrumcoccygeal Region of the coccyxRELATED TERMSVertenra A single backboneVertebrae BackbonesSpinal column Bone tissue surrounding the spinal cavitySpinal cord Nervous tissue within the spinal cavityDisk A pad of cartilage between vertebraeV. Positional and directional termsThe follo