10.2 神经系统介绍
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In the Blink of an Eye
::在眼睛的闪闪闪闪闪闪闪闪闪闪闪闪的闪闪闪闪闪闪闪的闪闪闪闪闪闪闪的闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪闪As you drive into a parking lot, a boy on a skateboard suddenly flies in front of your car across your field of . You see the boy in the nick of time and react immediately. You slam on the brakes and steer sharply to the right — all in the blink of an eye. You avoid a collision, but just barely. You’re shaken up, but thankful that no one was hurt. How did you respond so quickly? Rapid responses like this are controlled by your nervous system.
::当你开车进入停车场时,滑板上的一个男孩突然在车前飞过你的田野。你看到那个男孩在时间的尽头,立即反应。你踩刹车,在一眨眼就向右倾斜。你避免了碰撞,但只是勉强而已。你惊慌失措,但感谢无人受伤。你怎么反应这么快?这种快速反应是由你的神经系统控制的。Overview of the Nervous System
::神经系统概览The nervous system , which is illustrated in the sketch , is the human organ system that coordinates all of the body’s voluntary and involuntary actions, by transmitting electrical signals to and from different parts of the body. Specifically, the nervous system extracts information from the internal and external environments, using sensory receptors . Usually, it then sends signals encoding this information to the brain , which processes the information to determine an appropriate response. Finally, the brain sends signals to , organs , or glands to bring about the response. In the example above, your detected the boy, the information traveled to your brain, and your brain told your body to act so as to avoid a collision.
::素描中展示的神经系统是人体器官系统,它通过向身体不同部位传送电讯,协调身体所有自愿和非自愿行为。具体地说,神经系统利用感官受体,从内部和外部环境中提取信息。通常,神经系统然后向大脑发送信号,将这些信息编码到大脑,通过处理信息来确定适当的反应。最后,大脑向人体、器官或腺发送信号,以产生反应。在上文的例子中,你发现了男孩,信息传播到你的大脑,你的大脑告诉身体如何行动以避免碰撞。The human nervous system consists of the brain and spinal cord (central nervous system) and a network of branching nerves that travel throughout the body (peripheral nervous system). Some of the major nerves in the peripheral system are identified in this drawing.
::人类神经系统包括大脑和脊髓(中枢神经系统)以及贯穿整个身体的外科神经网络(外科神经系统 ) 。 边缘系统的某些主要神经系统在这个图中被识别出来。Signals of the Nervous System
::神经系统信号The signals sent by the nervous system are electrical signals called , and they are transmitted by special nervous system called (or nerve cells), like the one in the figure . Long projections (called axons) from neurons carry nerve impulses directly to specific target cells . A cell that receives nerve impulses from a neuron may be excited to perform a function, inhibited from carrying out an action, or otherwise controlled. In this way, the information transmitted by the nervous system is specific to particular cells and is transmitted very rapidly. In fact, the fastest nerve impulses travel at speeds greater than 100 meters per second! Compare this to the chemical messages carried by the that are secreted into the by . These hormonal messages are “broadcast” to all the cells of the body, and they can travel only as quickly as the blood flows through the .
::神经系统发送的信号被称作电子信号,它们通过特殊神经系统(或神经细胞)传送,就像图中的数字一样。神经元的长期预测(所谓的斧头)将神经冲动直接传送到特定的目标细胞。一个从神经元接收神经脉冲的细胞可能会兴奋地起作用,无法采取行动,或受到其他控制。通过这种方式,神经系统传递的信息是特定细胞所特有的,而且传播速度非常快。事实上,最快的神经脉冲速度超过每秒100米!比照这个由神经元秘密传送到特定目标细胞的化学信息。这些荷尔蒙信息“传播”到身体的所有细胞,它们只能以血液流过的速度快速移动。This simple model of a nerve cell shows part of its long axon (pointing down), which carries nerve impulses to other cells. The multiple shorter projections are called dendrites, and they receive nerve impulses from other cells.
::这种简单的神经细胞模型显示了它的一部分长轴(指向下 ) , 它将神经冲动带到其他细胞。 多个较短的预测被称为 dendrite,它们从其他细胞得到神经脉冲。Organization of the Nervous System
::神经系统组织As you might predict, the human nervous system is very complex. It has multiple divisions, beginning with its two main parts, the (CNS) and the (PNS), as shown in the diagram . The CNS includes the brain and spinal cord , and the PNS consists mainly of nerves , which are bundles of axons from neurons. The nerves of the PNS connect the CNS to the rest of the body. You can learn much more about the CNS by reading the concept Central Nervous System .
::正如你可能预测的那样,人类神经系统非常复杂。它有多种分解,从图中显示的(CNS)和(PNS)这两个主要部分开始。CNS包括大脑和脊髓,而PNS主要由神经组成,神经是神经的斧子包。PNS的神经将CNS与身体的其余部分连接在一起。通过阅读中央神经系统的概念,你可以更多地了解CNS。The two main divisions of the nervous system: the central nervous system (CNS) — which includes the brain and spinal cord — and the peripheral nervous system (PNS), which includes nerves and ganglia (singular, ganglion), which transmit information between the CNS to the rest of the body.
::神经系统的两个主要部分:中枢神经系统(包括大脑和脊髓)和外围神经系统(包括神经和帮派(同源、交织)),后者在中枢神经系统之间向身体其余部分传递信息。The PNS can be further subdivided into two divisions, known as the autonomic and somatic nervous systems ( as shown ). These divisions control different types of functions, and they often interact with the CNS to carry out these functions. The somatic nervous system controls activities that are under voluntary control, such as turning a steering wheel. The autonomic nervous system controls activities that are not under voluntary control, such as digesting a meal. The autonomic nervous system has t hree main divisions: the sympathetic division (which controls the fight-or- flight response during emergencies), the parasympathetic division (which controls the routine “housekeeping” functions of the body at other times), and the enteric division (which provides local control of the digestive system). You can learn more about the PNS and its subdivisions by reading the concept Peripheral Nervous System .
::PNS可进一步细分为两个部分,称为自动和体能神经系统(如所示)。这些部分控制着不同类型的功能,它们经常与CNS互动以履行这些功能。体能神经系统控制着自愿控制的活动,如方向盘。自能神经系统控制着不受自愿控制的活动,如消化食物等。自能神经系统有三个主要部分:同情性部分(在紧急情况下控制战斗或飞行反应)、寄生体(在其他时间控制着身体的常规“内部管理”功能)和内科部分(对消化系统进行局部控制)。您可以通过阅读 Periferal Nervous System的概念,更多地了解PNS及其子部分。Summary
::摘要-
The nervous system is the human organ system that coordinates all of the body’s voluntary and involuntary actions, by transmitting signals to and from different parts of the body.
::神经系统是人体器官系统,通过向身体不同部分传送信号,协调身体所有自愿和非自愿行为。 -
The nervous system has two major divisions, called the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS
includes
the brain and spinal cord, and the PNS consists mainly of nerves that connect the CNS with the rest of the body.
::神经系统分为两大部分,即中枢神经系统(CNS)和外围神经系统(PNS ) 。 中枢神经系统(CNS ) 包括大脑和脊髓,而中枢神经系统(PNS ) 主要由连接中枢神经系统和身体其他部分的神经组成。 -
The PNS
can be subdivided into
two major divisions: the somatic nervous system and the autonomic nervous system.The somatic system controls activities that are under voluntary control. The autonomic system controls activities that are not under voluntary control. The autonomic nervous system is further divided into the sympathetic division (which controls the fight-or-flight response), the parasympathetic division (which controls most routine involuntary responses),
and the enteric division (which provides local control of the digestive system).
::PNS可细分为两大部分:体能神经系统和自动神经系统。体能系统控制在自愿控制下的活动。自动系统控制不在自愿控制下的活动。自动神经系统进一步划分为同情分(控制战斗或飞行反应)、寄生虫病分(控制大多数例行非自愿反应)和肠道分(对消化系统进行局部控制)。 -
Electrical signals sent by the nervous system are called nerve impulses. They are transmitted by special cells called neurons. Nerve impulses can travel to specific target cells very rapidly.
::神经系统发送的电信号被称为神经脉冲,它们通过被称为神经元的特殊细胞传播。神经脉冲可以非常快地传送到特定的目标细胞。
Review
::回顾1. List the general steps through which the nervous system generates an appropriate response to information f rom the internal and external environments .
::1. 列出神经系统对内部和外部环境信息作出适当反应的一般步骤。2. What are neurons?
::2. 什么是神经元?3. Compare and contrast the central and peripheral nervous systems.
::3. 比较和比较中央和外围神经系统。4. Which major division of the peripheral nervous system allows you to walk to class? Which major division of the peripheral nervous system controls your heart rate ?
::4. 外围神经系统的哪个主要部分允许你步行去上课?外围神经系统的哪个主要部分控制了你的心率?5. Identify the functions of the t hree main divisions of the autonomic nervous system.
::5. 确定自主神经系统三个主要部门的职能。6. What is an axon, and what is its function?
::6. 什么是轴,其功能是什么?7. True or False: A nerve impulse always causes the target cell to perform an action.
::7. 真实或假:神经冲动总是导致目标细胞采取行动。8. True or False: The spinal cord is not considered part of the peripheral nervous system.
::8. 真实或假:脊髓不被视为外围神经系统的一部分。9. Define nerve impulses.
::9. 界定神经冲动。10. Explain why signals in the nervous system are generally more targeted and specific than signals in the endocrine system.
::10. 解释为什么神经系统中的信号一般比内分泌系统中的信号更有针对性和更加具体。11. Explain generally how the brain and spinal cord can interact with and control the rest of the body.
::11. 一般性地解释大脑和脊髓如何与身体其他部位相互作用和控制。12. ___________ actions are performed without the person thinking about them.
::12. 执行行动时不考虑有关的人。13. The fight-or-flight response is controlled by the...
::13. 战斗或飞行反应由...a. autonomic nervous system
::a. 自自主神经系统b. somatic nervous system
::b. 体神经系统c. fast nervous system
::c. 快速神经系统d. parasympathetic nervous system
::d. 寄生虫同情性神经系统14. How are nerves and neurons related?
::14. 神经和神经元如何相关?15. What type of information from the outside environment do you think is detected by sensory receptors in your ears?
::15. 你认为耳朵中的感官受体检测到什么类型的外部环境信息?Explore More
::探索更多Professor Megan Moynahan is working with teams of world-renowned researchers developing an artificial nervous system, with the hope that it will give people with paralysis the ability to do what would otherwise be impossible for them. Watch her TED talk about th is research in the video below.
::梅根·莫伊纳汉教授正在与世界知名研究人员团队合作开发一个人工神经系统,希望这将使麻痹者有能力做否则他们不可能做的事情。在下面的视频中观看她的TED关于这项研究的演讲。 -
The nervous system is the human organ system that coordinates all of the body’s voluntary and involuntary actions, by transmitting signals to and from different parts of the body.
