尿的形成与排出

尿的形成与排出 第二节 尿的形成与排出 教学目标 知识目标: 了解泌尿系统的组成及各器官的位置和功能，理解排泄的概念，掌握肾 脏的结构与尿液的形成过程。 能力目标: 通过观察肾脏的内部结构(实物)，通过观察泌尿系统模式图、肾结构示意图、尿的形成示意图和膀胱的剖面图，培养学生的观察能力和思维能力。 情感态度价值目标: 通过学习泌尿系统的卫生知识，提高学生保健能力，培养学生养成良好的卫生习惯。 重点、难点分析 1(本章的重点是排泄的概念，肾脏的结构和尿液的形成过程。因为: (1)学生对排泄的概念常常有不确切的认识。他们从大众传播媒体得知排便、排尿都是排泄，这种错误认识往往是根深蒂固的。若学习了人体生理卫生还不能扭转这个错误认识，不懂排泄的正确含义，本章的学习就失败了。故排泄的概念是重点。 (2)肾脏是尿液形成的结构基础，尿液是排泄的主要途径。本章的主题是排泄，主要介绍泌尿系统的结构与功能，故肾脏的结构和尿液的形成是重点。 2(肾单位的结构和尿液的形成过程是难点。因为: (1)肾单位结构复杂，又不能用眼直接看到。即使有条件的学校，给学生创造在显微镜下观察肾脏切片的机会，学生也很难找到完整的肾单位。而肾单位是产生尿液的结构单位，是看不到却很重要的关键知识点。突破肾单位这个难点可以为尿液的形成打好基础。 (2)尿液的形成过程难度更大。肾小球的滤过作用涉及到原尿的形成与成分;肾小管的重吸收作用涉及到终尿形成与成分。这里必须让学生明白肾单位中血液的来龙去脉和尿液的产生与排出途径，也就是说要血路、尿路都清楚。然而，让学生理解看不到的结构与其功能确有难度。 advantages, facing the Yangtze River Delta, Pearl River Delta, Shandong peninsula, Beijing-Tianjin-Tangshan area, targeted investment promotion several times. Industry-led unit and various town streets are developing detailed promotion plans, the basis of what is specific to each industry, has formed a kind of scale, need to bring in the kind of projects each town street has the kind of resources, what location, focus on the development of the kind of industries. Four stroke technology and science. Determinants of technology is the County's economic development through scientific and technological innovation, improve product value-added and improve economic competitiveness, is the inevitable way to achieve leapfrog development. Talent is the city center city's first resource, is the primary industry development, and revitalization of the social protection. So, in terms of skills: to catch ... Competitive. Encouraging enterprises to actively undertake science and technology projects, strengthening research cooperation, using advanced technology to increase the added value of their products to ensure that introduction of transforming scientific and technological achievements during the year ... ... New research enterprises ... ... Home, creating innovative platforms ... ... Generic classifier. In: first, we must strengthen the cultivation of talent, efforts to increase vocational education and training and meet the basic demand of enterprise development. Then introduced a number of the county needed scarce education, health professionals, meet social development needs to invest more in machinery, pharmaceutical manufacturing research and development in higher education, such as the introduction of talent to meet the need. Third, we must rely on ... ... Post-doctoral workstation, ... ... Food research station platform, to the XX University to find experts 教学过程 一、本章的参考课时为2课时。 二、第一课时: 1(引入新课:回忆呼吸的全过程。 设疑:呼吸全过程的最后一步，组织里的气体交换，将血液中的氧供给了细胞，氧进入细胞去做什么,组织细胞里的二氧化碳总是比动脉血多，这些二氧化碳是从哪里来的, 解疑:原来，人体通过消化、吸收得到的营养物质，在细胞内被利用。其中，有机物的分解通常需要氧的参与。有机物分解消耗了氧，产生了二氧化碳。 引出本章课题:有机物的分解还产生水、尿素等其他废物(当然，有些废物能在体内“变废为宝”，不宜称为废物)。这些物质通常被称为代谢终产物。它们在人体内积聚多了，对人体有害，必须及时排出体外。这就是本章要学习的课题——排泄。 2(比较排泄与排便(为了减轻学生的学习负担，应尽可能少给或不给专业性较强的名词术语，故不宜给排遗的概念)的区别，理解排泄的概念。 以小组讨论的方式进行对比:二者的排出物分别是什么,分别在身体的什么部位产生的,排出的途径各是什么,排泄的主要途径是什么, 在进行这部分讨论时，笔者的一组学生曾在讨论时查了《新华字典》对排泄的解释，看到字典中把排便列为排泄的内容之一，经讨论后提出:对于排泄这个概念，生物与字典的解释不同，我们信谁的,生物老师说的和以前我们听到的家长说的、电视科普节目中演过的，还有其他老师说的不一样，谁的对, 笔者是这样处理这个问题的:首先，笔者扬了学生“不惟书、不惟上”，探究问题、追求真理的精神。然后，建议同学通过学习本章知识、经过小组讨论或争论，自己做出判断。最后，请学生课后去查其它字典或词典。 在学生课后查过的字典和词典中，《辞海》对排泄的注解是科学的，符合生理学对排泄的定义。其它字典或词典中对排泄的解释均有错误。学生通过自己的思考和小组的讨论，加深了对排泄概念的理解。有的组还给出版这些工具书的单位写了信，希望他们修改这个词条。 3(观察泌尿系统的模型或挂图，认识泌尿系统的组成。 同桌两个同学互相说一说，泌尿系统的组成。提醒学生想着自己身体泌尿系统的主要器官的功能。 advantages, facing the Yangtze River Delta, Pearl River Delta, Shandong peninsula, Beijing-Tianjin-Tangshan area, targeted investment promotion several times. Industry-led unit and various town streets are developing detailed promotion plans, the basis of what is specific to each industry, has formed a kind of scale, need to bring in the kind of projects each town street has the kind of resources, what location, focus on the development of the kind of industries. Four stroke technology and science. Determinants of technology is the County's economic development through scientific and technological innovation, improve product value-added and improve economic competitiveness, is the inevitable way to achieve leapfrog development. Talent is the city center city's first resource, is the primary industry development, and revitalization of the social protection. So, in terms of skills: to catch ... Competitive. Encouraging enterprises to actively undertake science and technology projects, strengthening research cooperation, using advanced technology to increase the added value of their products to ensure that introduction of transforming scientific and technological achievements during the year ... ... New research enterprises ... ... Home, creating innovative platforms ... ... Generic classifier. In: first, we must strengthen the cultivation of talent, efforts to increase vocational education and training and meet the basic demand of enterprise development. Then introduced a number of the county needed scarce education, health professionals, meet social development needs to invest more in machinery, pharmaceutical manufacturing research and development in higher education, such as the introduction of talent to meet the need. Third, we must rely on ... ... Post-doctoral workstation, ... ... Food research station platform, to the XX University to find experts 4(通过观察与实验活动，认识肾脏的结构: 活动(1)，观察肾脏的内部结构，以小组为单位，便于学生观察得更细致，讨论得更充分。每个小组最好都有一个标本进行观察。观察后的肾脏可以用福尔马林浸泡起来，制成浸制标本，供下一届学生观察。 通过观察与小组讨论，认识与肾脏相通的管道，肾门处的血管与输尿管;肾的皮质与髓质;肾盂。 活动(2)，有条件的学校可以安排学生在显微镜下观察小鼠肾脏纵切片，在显微镜的视野中找到较完整的肾小体。没有条件的学校可以通过看挂图、看投影片等认识肾小体。教师还可以制造简单的直观教具，如，向气球内吹气，当气球稍鼓时，一只手捏紧进气口，另一只手将鼓起的气球向下按，模拟肾小囊等。通过实验、观察并进行小组讨论，使学生自己归纳肾单位的结构。 进而由学生小结肾脏的结构。 5(请学生本课的知识，提示总结的范围:排泄的概念、泌尿系统的组成和肾脏的结构。 (为下堂课置疑:我们已经知道了肾脏的结构，那么，究竟尿液是怎样形6 成的,我们下堂课再学习。 【板书设计】 第七章 排泄 一、排泄——人体内的代谢终产物排出体外的过程。 途径:呼吸系统——二氧化碳、少量水; 皮肤——一部分水、少量无机盐、尿素; 泌尿系统——绝大部分的水无机盐尿素等。 二、泌尿系统的组成。 三、肾脏的结构: 1(肾脏纵剖:皮质、髓质、肾盂。 2(肾单位的结构。 advantages, facing the Yangtze River Delta, Pearl River Delta, Shandong peninsula, Beijing-Tianjin-Tangshan area, targeted investment promotion several times. Industry-led unit and various town streets are developing detailed promotion plans, the basis of what is specific to each industry, has formed a kind of scale, need to bring in the kind of projects each town street has the kind of resources, what location, focus on the development of the kind of industries. Four stroke technology and science. Determinants of technology is the County's economic development through scientific and technological innovation, improve product value-added and improve economic competitiveness, is the inevitable way to achieve leapfrog development. Talent is the city center city's first resource, is the primary industry development, and revitalization of the social protection. So, in terms of skills: to catch ... Competitive. Encouraging enterprises to actively undertake science and technology projects, strengthening research cooperation, using advanced technology to increase the added value of their products to ensure that introduction of transforming scientific and technological achievements during the year ... ... New research enterprises ... ... Home, creating innovative platforms ... ... Generic classifier. In: first, we must strengthen the cultivation of talent, efforts to increase vocational education and training and meet the basic demand of enterprise development. Then introduced a number of the county needed scarce education, health professionals, meet social development needs to invest more in machinery, pharmaceutical manufacturing research and development in higher education, such as the introduction of talent to meet the need. Third, we must rely on ... ... Post-doctoral workstation, ... ... Food research station platform, to the XX University to find experts 三、第二课时: 1(复习提问: (1)对照挂图简述泌尿系统的组成及各器官的主要功能。 (2)对照挂图说明肾单位的结构。 2(从学生答案引入新课。 我们已经知道肾脏是形成尿的场所，又知道肾脏是有100多万个肾单位构成的。那么，尿是怎样形成的,尿是如何排出体外的,我们应该了解哪些泌尿系统的卫生知识，怎样用这些知识指导我们养成良好的生活习惯,这些是本堂课要探索、解决的问题。 3(安排自学与讨论活动，学习尿的形成。 给学生一些相关数据，结合书上P(72尿的形成示意图，在复习了肾单位的结构以后，通过小组讨论，抓住结构特点学习尿的形成过程。 活动(1)，读书与思考。 参照尿的形成示意图，看书并思考以下问题。 ?尿的形成过程包括两个连续的阶段——滤过和重吸收。两个阶段中被滤过和被重吸收的物质分别是什么, ?肾单位的哪些结构特点与完成滤过和重吸收作用相适应, ?如图，在尿的形成示意图中，左上方血液进入球小动脉，左下方血液流出肾单位，血液在肾单位中发生了什么变化, ?参看下表，思考:血浆与原尿的主要区别是什么,原尿与终尿的主要区别是什么,终尿与血浆的主要区别是什么, 成分 水 蛋白质 葡萄糖 尿素 尿酸 无机盐 液体 血浆 900-930 70-80 1 0.3 0.04 9.0 原尿 970 微量 1 0.3 0.04 9.0 尿液 950 0 0 1.8 0.05 11.0 ?为什么健康人每天形成的原尿有150升，而每天排出的尿只有1.5升, ?尿的形成示意图中肾小管中的尿流向何处, advantages, facing the Yangtze River Delta, Pearl River Delta, Shandong peninsula, Beijing-Tianjin-Tangshan area, targeted investment promotion several times. Industry-led unit and various town streets are developing detailed promotion plans, the basis of what is specific to each industry, has formed a kind of scale, need to bring in the kind of projects each town street has the kind of resources, what location, focus on the development of the kind of industries. Four stroke technology and science. Determinants of technology is the County's economic development through scientific and technological innovation, improve product value-added and improve economic competitiveness, is the inevitable way to achieve leapfrog development. Talent is the city center city's first resource, is the primary industry development, and revitalization of the social protection. So, in terms of skills: to catch ... Competitive. Encouraging enterprises to actively undertake science and technology projects, strengthening research cooperation, using advanced technology to increase the added value of their products to ensure that introduction of transforming scientific and technological achievements during the year ... ... New research enterprises ... ... Home, creating innovative platforms ... ... Generic classifier. In: first, we must strengthen the cultivation of talent, efforts to increase vocational education and training and meet the basic demand of enterprise development. Then introduced a number of the county needed scarce education, health professionals, meet social development needs to invest more in machinery, pharmaceutical manufacturing research and development in higher education, such as the introduction of talent to meet the need. Third, we must rely on ... ... Post-doctoral workstation, ... ... Food research station platform, to the XX University to find experts 活动(2)，小组讨论思考题。经过讨论，请一个代表完整叙述尿的形成过程，其他组员补充，使答案完善。 希望在讨论中能提出与泌尿系统有关的其它问题，鼓励同学提问，提倡组内互助。 活动(3)，请一位同学到前面来，指图(或投影片)讲述尿的形成过程。教师点评。 4(以小组活动的学习方式，学习尿的排出。 ?参看泌尿系统模式图，了解尿的排出路径。 ?观察膀胱的模型或膀胱的剖面图，了解尿液排出的机制。重点学习膀胱壁的结构(平滑肌)与功能(贮存尿)，尿道括约肌的收缩与舒张，从而了解尿的排出。 ?通过讨论，了解排尿的意义。 5(通过小组讨论，学习泌尿系统的卫生。学习的目的重在指导自己日常生活，养成良好的卫生习惯。 6(小结:请学生概括尿的形成过程和尿的排出。 【板书设计】 四、尿的形成: 五、尿的排出: 六、排尿的意义和泌尿系统的卫生: 1(意义:?排出废物 ?调节水盐含量，维持组织细胞正常生理功能 2(卫生:?适量饮水 ?及时排尿 ?保持尿道外口清洁 advantages, facing the Yangtze River Delta, Pearl River Delta, Shandong peninsula, Beijing-Tianjin-Tangshan area, targeted investment promotion several times. Industry-led unit and various town streets are developing detailed promotion plans, the basis of what is specific to each industry, has formed a kind of scale, need to bring in the kind of projects each town street has the kind of resources, what location, focus on the development of the kind of industries. Four stroke technology and science. Determinants of technology is the County's economic development through scientific and technological innovation, improve product value-added and improve economic competitiveness, is the inevitable way to achieve leapfrog development. Talent is the city center city's first resource, is the primary industry development, and revitalization of the social protection. So, in terms of skills: to catch ... Competitive. Encouraging enterprises to actively undertake science and technology projects, strengthening research cooperation, using advanced technology to increase the added value of their products to ensure that introduction of transforming scientific and technological achievements during the year ... ... New research enterprises ... ... Home, creating innovative platforms ... ... Generic classifier. In: first, we must strengthen the cultivation of talent, efforts to increase vocational education and training and meet the basic demand of enterprise development. Then introduced a number of the county needed scarce education, health professionals, meet social development needs to invest more in machinery, pharmaceutical manufacturing research and development in higher education, such as the introduction of talent to meet the need. Third, we must rely on ... ... Post-doctoral workstation, ... ... Food research station platform, to the XX University to find experts