[终稿]第一章人体结构概述课件.ppt

1、第一章人体基本结构概述第一节 细胞的结构与功能Cell Structure and FunctionThe structure of the cell The plasma membrane forms the outer boundary of the cell.The nucleus directs the activities of the cell.Cytoplasm,between the nucleus and plasma membrane,is where most cell activities take place.Functions of the Cell 1.Cells

2、 are the basic unit of life.2.Cells provide protection and support.3.Cells allow for movement.4.Cells provide a means of communication.5.Cells metabolize and release energy.6.Cells provide for inheritance.How We See Cells 1.Light microscope allow us to visualize general features of cells.2.Electron

3、microscopes allow us to visualize the fine structure of cells.共聚焦显微镜透射电镜扫描电镜神经元的尼氏染色神经元的Golgi染色正常神经元中只存在神经微丝，神经微丝缠结中存在tau蛋白大箭头所指神经元为病态神经元，小箭头所指神经元为死亡的神经元神经元的荧光染色细胞骨架的荧光染色神经管形成（第3周）扫描电镜图像缠结中的部分受损的神经微丝The Plasma Membrane细胞膜 1.The plasma membrane passively or actively regulates what enters or leaves th

4、e cell.2.The plasma membrane is composed of a phospholipid bilayer in which proteins are suspended(fluid-mosaic model).细胞膜以液态脂质双分子层为基架，其中镶嵌有具有不同生理功能的蛋白质分子。极性头非极性尾亲水疏水亲水糖蛋白糖链糖脂外表面蛋白质分子内表面磷脂双层细胞骨架微丝胆固醇Membrane Lipids The predominant lipids of the plasma membrane are phospholipids and cholesterol.Phosp

5、holipids readily assemble to form a lipid bilayer,a double layer of lipid molecules,because they have a polar head and a nonpolar tail.Cholesterol is interspersed among the phospholipids and accounts for about a third of the total lipids in the plasma membrane.脂质双分子层 构成细胞膜的框架，具有多形性和流动性 在膜的脂质中，主要以磷脂为

6、主，约占总量的70%以上；其次是胆固醇，一般低于30%；还有少量属于鞘脂类的脂质。动物细胞膜中的磷脂主要有四种：磷脂酰胆碱、磷脂酰乙醇胺、磷脂酰丝氨酸和磷脂酰肌醇。Membrane Proteins 1.Membrane proteins functions as markers,attachment sites,channels,receptors,enzymes,and carriers.2.Some receptor molecules are linked to and control channel proteins.3.Some receptor molecules are lin

7、ked to G proteins,which,in turn,control numerous cellular activities.细胞膜蛋白 表面蛋白与脂质的结合较疏松，用一些损害性较小的化学处理方法，如改变溶液的离子浓度或酸碱度，就可能使它们与膜分离。结合蛋白与脂质结合甚紧密，只有使用一些能改变分子间相互作用勒的强处理手段，如使用一些特殊的化学除垢剂等，才能使之分离出来。细胞膜蛋白的功能 载体、通道、离子泵：与各种物质如离子和营养物质、代谢产物有选择、有条件地通过细胞膜有关；受体：与辨认和接受细胞环境中特异的化学性刺激或信号有关；抗原：起细胞“标志”的作用，供免疫系统或免疫物质辨认

8、其它功能不明的蛋白质果蝇细胞膜上的钾离子通道电镜照片钾离子通道化学结构图K+细胞膜糖类 细胞膜所含糖类甚少，主要是一些寡糖和多糖链，它们都以共价键的形式和膜内脂质或蛋白质结合，形成糖脂或糖蛋白；这些糖链绝大多数是裸露在膜的外表面一侧的。就目前所知，这些糖链的意义在于其单糖排列顺序上的特异性，因而可以作为细胞或所结合蛋白质的特异性“标志”。Plasma Membrane Transport细胞膜的物质转运功能 Substances enter and exit cells by active transport or by passive transport.物质以何种方式通过细胞膜转运主要取决

9、于以下几个因素：物质相对分子质量的大小 物质转运是顺浓度差还是逆浓度差 物质是脂溶性的还是水溶性的Movement Through the Plasma Membrane 1.Lipid-soluble molecules pass through the plasma membrane readily by dissolving in the lipid bilayer,2.Small molecules pass through membrane channels.Most channels are positively charged,allowing negatively charge

10、d ions and neutral molecules to pass through more readily than positively charged ions.3.Large polar substances(e.g.,glucose and amino acids)are transported through the membrane by carrier molecules.4.Larger pieces of material enter cells in vesicles.Diffusion（扩散）Diffusion（扩散）1.Diffusion is the move

11、ment of a substance from an area of higher concentration to one of lower concentration(with a concentration gradient).2.The concentration gradient is the difference in solute concentration between two points divided by the distance separating the points.3.The rate of diffusion increases with an incr

12、ease in the concentration gradient,an increase in temperature,a decrease in molecular size,and a decrease in viscosity.4.The end result of diffusion is a uniform distribution of molecules.5.Diffusion requires no expenditure of energy.单纯扩散(simple diffusion)单纯扩散是指脂溶性小分子物质从细胞膜高浓度一侧向低浓度一侧转运的过程。这是一种单纯的物理

13、过程。在人体，以单纯扩散方式进出细胞的物质很少，比较确定的有氧气、二氧化碳、一氧化氮和氨等气体分子。Predict 1 Uera is a toxic waste produced inside cells.It diffuse from the cells into the blood and is eliminated from the body by the kidney.What would happen to the intracellular and extracellular concentration of urea if the kidney stopped function

14、ing?血液透析Osmosis（渗透）Predict 2 What would happen to osmotic pressure if the membrane were nor selectively permeable but instead allowed all solutes and water to pass through it?Osmosis（渗透）1.Osmosis is the diffusion of water(solvent)across a selectively permeable membrane.2.Osmotic pressure is the forc

15、e required to prevent the movement of water across a selectively permeable membrane.3.Isosmotic solutions have the same concentration of solute particles,hypersmotic solutions have a greater concentration,and hyposmotic solutions have a lesser concentration of solute particles than a reference solut

16、ion.4.Cells placed in an isotonic solution neither swell nor shrink.In a hypertonic solution they shrink(crenate),and in a hypotonic solution they swell and may burst(lyse).等张溶液低张溶液高张溶液Filtration（滤过）1.Filtration is the movement of a liquid through a partition with holes that allow the liquid,but not

17、 everything in the liquid,to pass through them.2.Liquid movement results from a pressure difference across the partition.Mediated Transport Mechanisms Mediated transport is the movement of a substance across a membrane by means of a carrier molecules.The substances transported tend to be large,water

18、-soluble molecules.1.The carrier molecules have binding sites that bind with either a single transport molecule or a group of similar transport molecules.This selectiveness is called specificity.2.Similar molecules can compete for carrier molecules,with each reducing the rate of transport of the oth

19、er.3.Once all the carrier molecules are in use,the rate of transport cannot increase further(saturation).易化扩散(facilitated diffusion)水溶性或脂溶性很小的小分细物质不易通过细胞膜脂质层，需借助细胞膜上的特殊蛋白质才能从细胞膜高浓度一侧向低浓度一侧转运，这一过程称为易化扩散。载体转运 通道转运Predict 3 The transport of glucose into and out of most cell,such as muscle and fat cells

20、,occurs by facilitated diffusion.Once glucose enters a cell,it is rapidly converted to other molecules,such as glucose-6-phosphate or glycogen.What effect does this conversion have on the ability of the cell to acquire glucose?Explain.Active Transport（主动转运）Active transport can move substance against

21、 their concentration gradient and requires ATP.An exchange pump is an active-transport mechanism that simultaneously move two substances in opposite directions across the plasma membrane.In secondary active transport,an ion is moved across the plasma membrane by active transport,and energy produced

22、by the ion diffusing back down its concentration gradient can transport another molecule,such as glucose,against its concentration gradient.主动转运 主动转运指细胞通过本身的某种耗能过程，将某种物质的分子或离子由膜的低浓度一侧移向高浓度一侧的过程。钠泵、钙泵、氢泵都是对物质进行主动转运的蛋白质，这些蛋白质都以直接分解ATP为能量来源，对有关离子进行转运。钠钾泵钠泵的化学本质和功能钠泵活动的生理意义 形成细胞内高K+，为许多代谢反应创造必需的条件，如核糖体合

23、成蛋白质；将漏入的Na+转运到胞外，以维持胞质渗透压和细胞容积的相对稳定，防止过多的水分子进入细胞而形成水肿；形成膜两侧Na+和K+的浓度差，建立势能储备，为细胞生物电活动的产生奠定基础；钠泵活动造成的膜内外Na+的浓度差，是继发性主动转运的动力。主动转运的特点继发性主动转运 某些物质（如葡萄糖、氨基酸等）利用钠泵活动造成势能储备，即膜外高Na+而膜内低Na+的浓度差，在Na+内流的同时并同向（或逆向）转运入（出）胞。这种形式也称联合转运，多见于小肠吸收和肾小管的重吸收过程中。继发性主动转运 在继发性主动转运过程中，被转运的物质与联合转运的Na+方向相同，称为同向转运，如近端小管处葡萄糖与Na

24、+的同向转运。在继发性主动转运过程中，被转运的物质与联合转运的Na+方向相反，称为逆向转运，如Ca2+和Na+的逆向转运，即Na+-Ca2+交换。细胞膜的跨膜物质转运功能 Predict 4 In cardiac(heart)muscle cells,the concentration of intracellular Ca2+affect the force of heart contraction.The higher the intracellular Ca2+concentration,the greater the force of contraction.Na+/Ca2+coute

25、rtranspor helps to regulate intracellular Ca2+levels by transporting Ca2+out of cardiac muscle cells.Given that digitails slows the transport of Na+,should the heart beat more or less forcelly when exposed to this drug?Explain.Endocytosis and Exocytosis（入胞和出胞）1.Endocytosis is the bulk movement of ma

26、terials into cells.Phagocytosis is the bulk movement of solid materials into cells by the formation of a vesicle.Pinocytosis is similar to phagocytosis,except that the ingested materials is much smaller or is in solution.2.Exocytosis is the secretion of materials from cells by vesicle formation.3.En

27、docytosis and exocytosis use vesicles,can be specific(receptor-mediated endocytosis)for the substance transported,and required energy.受体介导的入胞出胞出胞和入胞 细胞对于一些大分子物质或物质团块，可以通过膜的结构和功能的改变，使之进出细胞，分别称之为出胞和入胞。出胞主要见于细胞的分泌活动。入胞指细胞外某些物质团块进入细胞的过程；如果进入的物质是固体的，称为吞噬，如果进入的物质是液性的，则称为吞饮。第二节 基本组织 Body Tissues 在结构和机能上具有密

28、切联系的细胞和细胞间质所组成的基本结构称组织。根据组织的一些共同的结构和机能特点，可把人体的组织归纳为四大类：上皮组织、结缔组织、肌组织和神经组织。Tissues are collections of similar cells and the substance surrounding them.The four primary tissue types are epithelial,connective,muscular and nervous tissues.一、上皮组织（Epithelial Tissue）上皮组织简称上皮，是由许多密集的上皮细胞和少量的细胞间质组成。上皮组织的细胞排列

29、紧密，形状规则，并有极性。其一极朝向表面和腔面称游离面。另一极为基底面。上皮组织与结缔组织之间以一层基膜相连。Epithelium consists of cells with little extracellular matrix,it covers surface,it has a basement membrane,and it does not have blood vessels.The basement membrane is secreted by the epithelial cells and attaches the epithelium to the underlying

30、 tissues.上皮组织类型（一）被覆上皮（二）腺上皮变移上皮：肾盏、肾盂、输尿管和膀胱等腔面被覆上皮单层上皮复层上皮单层扁平上皮单层立方上皮单层柱状上皮假复层纤毛柱状上皮复层变平上皮复层柱状上皮：睑结膜和男性尿道的腔面未角化：口腔、食管和阴道的腔面角化：皮肤的表皮被覆上皮的类型和分布单层扁平上皮内皮：心、血管和淋巴管的腔面间皮：腹膜、心包膜和胸膜表面其他：肺泡和肾小囊等上皮单层立方上皮单层柱状上皮粘液杯状细胞假复层纤毛柱状上皮纤毛复层扁平上皮变移上皮Predict 1 Explain the consequences of having(a)moist stratified epithel

31、ium rather than simple columnar epithelium lining the digestive tract,(b)moist stratified squamous epithelium rather than keratinized stratified squamous epithelium in the skin,and(c)simple columnar epithelium rather than moist stratidfied squamous epithelim linings the mouth.腺上皮（Glands）1.Glands are

32、 organs that secrete.Exocrine glands secrete through ducts,and endocrine glands release hormones that are absorbed directly into the blood.Glands 2.Glands are classified as unicellular or multicellular.Goblet cells are unicellular glands.Multicellular exocrine glands have ducts,which are simple or c

33、ompound(branched).The ducts can be tubular or end in small sacs(acini or alveoli).Tubular glands can be straight and coiled.Glands 3.Glands are classified according to their mode of secretion.Merocrine glands(部分分泌腺)(pancreas)secrete substances as they are produced,apocrine glands(顶分泌腺)(mammary gland

34、s)accumulate secretions that are released when a portion of the cell pinches off,and holocrine glands(全分泌腺)(sebaceous glands)accumulate secretions that are released when the cells ruptures and dies.二、结缔组织（Connective Tissue）结缔组织广泛分布于身体各部，种类多，形态多样。有细胞和大量细胞间质构成。细胞间质包括基质和纤维部分。基质呈均质状，纤维为细丝状。Connective ti

35、ssue is distinguished by its extracellular matrix.The extracellular matrix results from the activity of specilized connective tissue cells;in general,blast cells(成某某细胞）form the matrix,cyte cells（细胞）maintain it,and clast cells（破碎细胞）break it down.Fibroblasts（成纤维细胞）form protein fibers of many connectiv

36、e tissues,osteoblasts（成骨细胞 form bone,and chondroblasts（成软骨细胞）form cartilage.Adipose(fat)cells（脂肪细胞）,mast cells（肥大细胞）,white blood cells（白细胞）,marcrophages（巨噬细胞）,and mesenchymal cell（间质细胞）are commonly found in connective tissue.The extracellular matrix of connective tissue has protein fibers,ground sub

37、stances,and fluid as major components.Protein fibers of the Matrix 1.Collagen fibers（胶原纤维）structurally resemble ropes.They are strong and flexible but resist stretching.2.Reticular fibers（网状纤维）are fine collagen fibers that form a braching network that supports other cells and tissues.3.Elastin fiber

38、s（弹性纤维）have a structure similar to a spring.After being stretched they tend to return to their original shape.Other Matrix Molecules 1.Hyaluronic acid（透明质酸）makes fluids slippery.2.Proteoglycan（糖蛋白）aggregates trap water,which gives tissue the capacity to return to their original shape when compressed

39、 or deformed.3.Adhesive molecules hold proteoglycans together and to plasma membranes.结缔组织的类型Classification of Connective Tissue Connective tissue is classified according to the type of protein and the proportions of protein,ground substance,and fluid in the matrix.结缔组织固有结缔组织软骨组织疏松结缔组织骨组织血液透明软骨：主要分布

40、在关节软骨、肋骨、气管和支气管等处致密结缔组织网状组织脂肪组织规则致密结缔组织不规则致密结缔组织白脂肪组织黄脂肪组织弹性软骨：分布于耳廓及会厌等处纤维软骨：分布于椎间盘、耻骨联合等处疏松结缔组织基质成纤维细胞弹性纤维胶原纤维致密结缔组织脂肪组织基质软骨陷窝透明软骨软骨陷窝内的软骨细胞致密骨哈弗氏管骨陷窝内的骨细胞中央管骨小管血浆Predict 2 Explain the advantages of having elastic ligaments that extend from vertebra to vertebra in the vertebral column and why it w

41、ould be a disadvantage if tendons,which connect skeletal muscles to bone,were elastic.Predict 3 Scars consist of dense irrehular connective tissue made of collagen fibers.Vitamin C is required for collagen synthesis.Predict the effect of scurvy,which is a nutritional disease caused by Vitamin C defi

42、ciency,on wound healing.Predict 4 One of several changes caused by rheumatoid arthritis in joints is the replacement of hyaline cartilage with dense irregular collagenous connective tissue.Predict the effect of replacing hyaline cartilage with fibrous connective tissue.三、肌组织（Muscular Tissue）肌组织主要由高度

43、分化的肌细胞构成。肌细胞细长呈纤维状，因此称为肌纤维。肌纤维含有细肌丝和粗肌丝。Muscular tissue is composed of muscle fibers that contain actin and myosin filaments.根据结构、功能、分布和神经支配等特点，可将肌组织分为骨骼肌、平滑肌和心肌三种。Three types of muscular tissue are found in the body:skeletal,smooth,and cardiac muscle.骨骼肌Skeletal muscle Skeletal(striated voluntary)m

44、uscle attaches to bone and is responsible for body movement.Skeletal muscle cells are long,cylindrically shaped cells with many peripherally located nuclei.心肌Cardiac muscle Cardiac(striated involuntary)muscle cells are sylindrical,branching cells with a single,central nucleus.Cardiac muscles is foun

45、d in the heart and is responsible for pumping blood through the circulatory system.平滑肌Smooth Muscle Smooth(nonstriated involuntary)muscle forms the walls of hollow organs,the iris of the eye,and other structures.Its cells are spindle-shaped with a single,central nucleus.四、神经组织（Nervous Tissue）神经组织是神经

46、系统的主要组成部分，由神经细胞和神经胶质细胞组成。神经细胞又称神经元，具有接受刺激、传导冲动和整合信息的功能。1.Nervous tissue has the ability to conduct electric impulses and is composed of neurons(conductive cells)and neuroglial(support cells).2.Neurons have cell processes called dendrites and axons.The dendrites can receive electric impulses,and the

47、axons can conduct them.Neurons can be multipolar,bipolar or unipolar.髓鞘郎飞氏结树突神经组织神经元的结构运动神经元感觉神经元树突胞体核仁核轴突髓鞘 侧支郎飞氏结神经脉冲郎飞氏结胞体核核仁施旺细胞的核轴突神经脉冲神经脉冲髓鞘的形成核施旺鞘髓鞘施旺细胞轴突神经元和神经胶质细胞寡突胶质细胞轴突小胶质细胞室管膜细胞星状胶质细胞毛细血管神经元第三节 身体的结构层次 Organization of Body Parts Conceptually,the body has six structural level:the chemical

48、,cell,tissue,organ,organ system,and complete organism.原子分子大分子细胞器细胞组织系统器官有机体肝胃小肠大肠身体的结构层次Predict 1 One type of diabetes is a disorder in which the pancreas(an organ)fails to produce insulin,which is a chemical normally made by pancreatic cells and released into the circulation.List as many levels of

49、organization as you can in which this disorder could be corrected.人体组织、器官和系统的基本概念 细胞是人体形态结构和生理功能的基本单位。组织是由许多细胞和细胞间质组成的基本结构，具有多种类型。一般将组织分为上皮组织、结缔组织、肌肉组织和神经组织四种，称为基本组织。人体组织、器官和系统的基本概念 器官是由几种不同的组织结合在一起，构成具有一定形态和功能的结构，如胃、肺、肾等。在结构和功能上具有密切联系的器官结合在一起，共同执行某种特定的生理活动，即构成系统。Anatomical Terms解剖学常用术语 1、Anatomical

50、 position（解剖学姿势）在描述人体任何结构时，不论标本或模型以何种方位放置，都应以解剖学姿势为依据。standing erect,with face forward,arm at the sides,and palms and toes directed forward.身体直立，两眼向前平视，上肢下垂至躯干两侧，手掌向前，下肢并拢，足尖向前。上近远下外内前腹后背2、Relative Position of the Body Parts（方位）方位术语是用以描述人体结构的相互位置关系的术语，最常见的有：Superior-Inferior（上和下）（cranialis-caudalis)