章节大纲

  • 常规

    全部折叠 展开全部

  • 常态

    An arch made of stones illustrating stability and interconnectedness of body systems.

    What happens if stability is disrupted?
    ::如果稳定中断怎么办?

    Remove one stone and the whole arch collapses. The same is true for the . All the systems work together to maintain stability or homeostasis. Disrupt one system, and the whole body may be affected.
    ::移除一块石头和整个拱门的崩塌。对于 . . . . . . . . . . . . . . . . 所有系统 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

    Homeostasis
    ::常态

    All of the organs and organ systems of the human body work together like a well-oiled machine. This is because they are closely regulated by the nervous and endocrine systems. The controls virtually all body activities, and the secretes that regulate these activities. Functioning together, the organ systems supply body with all the substances they need and eliminate their wastes. They also keep temperature, pH, and other conditions at just the right levels to support life processes.
    ::人体的所有器官和器官系统都像一个油污良好的机器一样一起工作,这是因为它们受到神经和内分泌系统的严格控制。它们控制着几乎所有的身体活动,以及管理这些活动的秘诀。它们共同运作,器官系统提供它们需要的所有物质,并消除它们的废物。它们还将温度、pH和其他条件维持在支持生命过程的正确水平上。

    Maintaining Homeostasis
    ::保持原状状态

    The process in which organ systems work to maintain a stable internal environment is called homeostasis . Keeping a stable internal environment requires constant adjustments. Here are just three of the many ways that human organ systems help the body maintain homeostasis:
    ::器官系统为维持稳定的内部环境而工作的过程被称为 " 稳健 " 。 保持稳定的内部环境需要不断调整。 这只是人体器官系统帮助身体保持稳健的许多方法中的三种:

    • : A high concentration of carbon dioxide in the triggers faster . The lungs exhale more frequently, which removes carbon dioxide from the body more quickly.
      ::: 触发器中二氧化碳的高浓度更快。肺部呼吸频率更频繁,从而更快地将二氧化碳从体内清除出来。
    • : A low level of in the blood triggers retention of water by the . The kidneys produce more concentrated urine , so less water is lost from the body.
      :::血液中的低浓度导致肾脏产生更集中的尿液,因此从身体中流失的水较少。
    • Endocrine system: A high concentration of sugar in the blood triggers secretion of insulin by an endocrine gland called the pancreas . Insulin is a hormone that helps cells absorb sugar from the blood.
      ::内分泌系统:血液中高浓度的糖触发了胰岛素的分泌,内分泌腺叫做胰腺。胰岛素是一种激素,有助于细胞吸收血液中的糖。

    So how does your body maintain homeostasis? The regulation of your internal environment is done primarily through negative feedback . Negative feedback is a response to a stimulus that keeps a variable close to a set value ( Figure ). Essentially, it "shuts off" or "turns on" a system when it varies from a set value.
    ::您的身体如何保持顺常态 ? 您内部环境的调节主要通过负反馈进行 。 负反馈是对使变量接近设定值( 图)的刺激的反应 。 基本上, 它“ 关闭 ” 或“ 启用 ” 系统, 当它与设定值不同时 。

    For example, your body has an internal thermostat. During a winter day, in your house a thermostat the temperature in a room and responds by turning on or off the heater. Your body acts in much the same way. When body temperature rises, receptors in the skin and the brain sense the temperature change. The temperature change triggers a command from the brain. This command can cause several responses. If you are too hot, the skin makes sweat and near the skin surface dilate. This response helps decrease body temperature.
    ::例如,你的身体有一个内部自动调温器。在冬天的一天,你家里对房间里的温度进行自动调温,通过打开取暖器或关闭取暖器作出反应。你的身体作用大致相同。当身体温度上升时,皮肤的受体和大脑的大脑感应温度变化。温度变化触发了大脑的指令。这个命令可以产生若干反应。如果皮肤太热,皮肤会出汗,皮肤表面会膨胀。这种反应有助于降低体温。

    Another example of negative feedback has to do with blood glucose levels. When glucose (sugar) levels in the blood are too high, the pancreas secretes insulin to stimulate the absorption of glucose and the conversion of glucose into glycogen, which is stored in the liver . As blood glucose levels decrease, less insulin is produced. When glucose levels are too low, another hormone called glucagon is produced, which causes the liver to convert glycogen back to glucose.
    ::另一个负面反馈的例子与血糖水平有关。当血液中的葡萄糖(糖)水平太高时,胰腺分泌素可以刺激吸收葡萄糖,并将葡萄糖转化成谷素,后者储存在肝脏中。随着血糖水平的下降,会减少胰岛素的产生。当葡萄糖水平过低时,会产生另一种叫作甘油的荷尔蒙,导致肝脏将甘油重新转化成葡萄糖。

    Flowchart illustrating the negative feedback process in maintaining body temperature homeostasis.

    Feedback Regulation. If a raise in body temperature (stimulus) is detected (receptor), a signal will cause the brain to maintain homeostasis (response). Once the body temperature returns to normal, negative feedback will cause the response to end. This sequence of stimulus-receptor-signal-response is used throughout the body to maintain homeostasis.
    ::反馈调节。 如果检测到身体温度(刺激性)升高(受体),信号将使大脑保持顺势状态(反应 ) 。 一旦身体温度恢复到正常状态,负反馈就会导致反应结束。 刺激性-受体-信号-响应序列在整个身体中用于保持顺势状态。

    Positive Feedback
    ::积极反馈

    Some processes in the body are regulated by positive feedback . Positive feedback is when a response to an event increases the likelihood of the event to continue. An example of positive feedback is milk production in nursing mothers. As the baby drinks her mother's milk, the hormone prolactin, a chemical signal, is released. The more the baby suckles, the more prolactin is released, which causes more milk to be produced. Other examples of positive feedback include contractions during childbirth. When constrictions in the uterus push a baby into the birth canal, additional contractions occur.
    ::身体中的某些过程由积极的反馈来调节。积极的反馈是当对事件的反应增加事件继续发生的可能性时。积极的反馈的一个例子是哺乳母亲的牛奶生产。当婴儿喝母亲的牛奶时,就会释放出一种化学信号,即荷尔蒙蛋白,即化学信号。婴儿的吸食量越多,蛋白素就会释放出来,从而产生更多的牛奶。其他积极的反馈的例子包括分娩期间的收缩。当子宫内收缩将婴儿推入产运河时,就会发生更多的收缩。

    Failure of Homeostasis
    ::原固态失灵

    Many homeostatic mechanisms such as these work continuously to maintain stable conditions in the human body. Sometimes, however, the mechanisms fail. When they do, cells may not get everything they need, or toxic wastes may accumulate in the body. If homeostasis is not restored, the imbalance may lead to disease or even death.
    ::许多诸如此类的自闭机制持续地维持人体的稳定条件,但有时机制失败。 当它们出现时,细胞可能得不到它们所需要的一切,或者有毒废物可能累积在体内。 如果不恢复自闭症,这种不平衡可能会导致疾病甚至死亡。

      

     

     

    Science Friday : Diary of A Snakebite Death
    ::科学星期五:蛇咬死亡日记

    What does it feel like to be bitten by a venomous snake? In this video by Science Friday , learn about how Dr. Karl P. Schmidt wrote about the effects of snake bite venom while he was dying.
    ::被毒蛇咬的感觉是什么?在科学周五的这段视频中, 了解卡尔·施密特博士在临死时 如何写下蛇咬毒液的影响。

     

    Summary
    ::摘要

    • All of the organ systems of the body work together to maintain homeostasis of the organism.
      ::人体的所有器官系统都共同努力保持有机体的顺常态。
    • If homeostasis fails, death or disease may result.
      ::如果自闭症失败,可能会导致死亡或疾病。

    Review
    ::回顾

    1. What is homeostasis?
      ::什么是自闭症?
    2. Describe how one of the human organ systems helps maintain homeostasis.
      ::描述一个人体器官系统如何帮助保持自足。
    3. A house has several systems, such as the electrical system, plumbing system, and heating and cooling system. In what ways are the systems of a house similar to human body systems?
      ::房屋有多个系统,如电气系统、管道系统、供暖和冷却系统。 房屋的系统与人体系统有什么相似之处?