学位英语课件知识重点lectureunit8.ppt

Too Much Too Soon,questions,1. What are the current trends and ideas about children? 2. What examples are given to show that children are introduced to too much academic training too early?,questions,3. What is vital for brain development and learning, according to recent neurological findings? 4. Whats the first step of brain development for a child after birth? 5. How does experience shape the architecture of the brain? 6. Whats the authors opinion about environmental stimuli? 7. What neurological factor is the most crucial in facilitating a childs learning? 8. Whats the process of brain development? How does a brain learn?,questions,9. Why is myelin so important? 10. What else do we learn about myelin from the article? 11. What does the author want to illustrate with the example of penmanship?,given,Given: prep鉴于,考虑到 considering 鉴于当时的情况，你已经处理得很好了。 Given the circumstances, youve coped well. 考虑到时间很紧，我认为他们的工作完成得很不错。 Given that there was so little time, I think theyve done a good job.,hype,hype:大肆宣传，天花乱坠的广告 尽管媒体大肆宣传，我觉得这部电影很让人失望。 Despite all the media hype, I found the film very disappointing.,pave the way for,pave the way for: 为（某事物）创造条件， 为铺平道路 The proposals will pave the way for a speedy resolution to the problem. 这些提议将为该问题的迅速解决铺平道路。 Getting a quality education will pave the way for your future.,overload,使过载；使超载 During hot weather, the citys electrical system is often overloaded by fans and air conditioners. 使负担过重 She has overloaded her schedule with work, study, and family responsibilities. 她的日程表上排满了工作、学习、家务等, 使自己负担过重。 他们的职员超负荷工作。 Their staff are heavily overloaded with work.,shape,shape: 决定性质；对有巨大影响 His childhood was shaped by a loving relationship with his elder brother. 他与哥哥之间的挚爱情谊对他童年影响很大。,neuron,A neuron is a nerve cell that is the basic building block of the nervous system. A one-year old human has about 100 billion neurons. A typical brain neuron will have connections with at least 1,000 other neurons. A typical neuron possesses a cell body (often called the soma), dendrites, and an axon. The cell body of a neuron frequently gives rise to multiple dendrites, but never to more than one axon.,The brain is a vastly complicated signaling system, with neurons forming the basis of that system. Electrochemical signals flow in one direction only in neurons, originating at the dendrites or cell body (usually in response to stimulation from other neurons) and propagating along axon branches which terminate on the dendrites or cell bodies of perhaps thousands of other neurons. The connections between the ends of axons and the dendrites or cell bodies of other neurons are specialized structures called synapses. At the majority of synapses, signals are sent from the axon of one neuron to a dendrite of another.,神经系统的基本结构和功能单位是神经细胞,即神经元(neurons)。细胞体和从细胞延伸的突起所组成,神经元伸出的突起分2种，即树突（dendrites）和轴突（axon） 。 树突，大多数神经元具有多个树突，每个树突都较短，分支较多，可扩大接受信息面积。树突小分支表面有大量的细刺状突起，称为棘突或棘刺（spine）。这些棘突是其他神经元突起的终末支和树突形成突触的接触点。树突的机能是接受其他神经元传来的神经冲动，并将冲动传到胞体。树突和细胞体的表膜都有接受刺激的功能。它们的表面富有小棘状突起，是与其它神经元的轴突相连（突触）之处。,轴突，每个神经元只有一个轴突。轴突一般都比树突长，其功能是把从树突和细胞表面传入细胞体的神经冲动传出到其他神经元或效应器。所以，树突是传入纤维，轴突是传出纤维。轴突末端分支多，形成终末支。终末支末梢形成许多球形的突触小体（突触终结）。突触小体贴附于另一个神经元的树突或胞体表面，形成突触（synapse）。轴突上有髓鞘，有些轴突的髓鞘很厚，是由许旺氏细胞（Schwanns cell）的胞膜围绕轴突（轴柱）反复多层螺旋卷绕所形成；有些轴突的髓鞘却很薄，是只由一层许旺氏细胞包绕而成。在神经纤维上每隔一定距离（50微米1毫米）就出现间断，轴突在此间断处裸露，特称为郎飞氏结（Ran-viers node）。轴突的机能主要是传导神经冲动，能将冲动传递到另一个神经元或所支配的细胞上(传递细胞本体的动作电位至突触)。在神经系统中，轴突是主要的神经信号传递渠道。大量轴突牵连一起，以其外型类似而称为神经纤维。,在脊椎动物中，许多神经元的轴突被髓鞘包裹。髓鞘的成分是许旺细胞（Schwann cell)。目前知道髓鞘的功能有三。一是提供轴突与周围组织，例如相邻的轴突之间的电气绝缘，以避免干扰。二是通过一种称为“跳跃式传导”的机制来加快动作电位的传递。三是在一些轴突受损的情况下引导轴突的再生。一个轴突的髓鞘是由许多沿轴突排列的许旺细胞构成的，相邻的许旺细胞之间的轴突细胞膜没有髓鞘，这些裸露的部分叫做兰氏结（Ranviers node，亦作“郎飞结”） 动作电位在轴突上的传导速度因有无髓鞘而异。有髓鞘的轴突传导动作电位的速度较快，可达到100 m/s左右。(髓鞘的主要成分是磷脂，有绝缘并增进神经传导的作用。 ),escalation,escalate: increase rapidly迅速增加，迅速增长; 加剧；become or cause to become more intense or serious（使）恶化，（使）升级 重组导致成本急剧上涨。 The reorganization has led to a dramatic escalation in costs.,There is no denying ,There is no denying sth无可否认 (spoken) used to say that it is very clear that sth is true. 她是一名优秀的学者，这一点无可否认。 There is no denying the fact that she is an excellent scholar. Theres no denying that this is a serious blow.,exacerbate,exacerbate: to make a bad situation worse. 中央政府的政策使这些问题更加严重。 These problems were exacerbated by central governments policies. 他们给她吃的药只是加重了她的痛楚。 The drugs they gave her only exacerbated the pain.,make sense,make sense: 有道理，有意义 That sentence doesnt make sense (= has no meaning). 这个句子说不通。 Theres no sense in sth毫无道理（spoken）used to say that it is not sensible to do something Theres no sense in going home before the film. 看电影前回家一趟很不明智。,The International Montessori School of Beijing (MSB) employees teach students on how to recognize professions. Court