章节大纲

  • A close-up view of red kidney beans grouped together, resembling isolated kidneys.

    Why is a bean-shaped organ so important?
    ::为什么豆形器官如此重要?

    Shown above are the isolated kidneys from many little mice. OK, they're really just kidney beans. But this is what the important kidney looks like. Why is it so important? Your kidneys filter and remove wastes from your .
    ::上面显示的是许多小老鼠的孤立肾脏。 好了,它们其实只是肾豆。 但这就是重要的肾脏的长相。 为什么它如此重要? 你的肾脏过滤器和清除你的垃圾。

    The Kidneys
    ::肾脏

    The kidneys are a pair of bean-shaped organs just above the waist. They are important organs with many functions in the body, including producing , absorbing minerals , and filtering blood and producing urine .
    ::肾脏是腰部上方一对豆形器官,是体内许多功能的重要器官,包括生产、吸收矿物、过滤血液和尿液。

    A cross-section of a kidney is shown in Figure . The function of the kidney is to filter blood and form urine. Urine is the liquid waste product of the body that is excreted by the . Wastes in the blood come from the normal breakdown of tissues , such as , and from food . The body uses food for energy . After the body has taken the nutrients it needs from food, some of the wastes are absorbed into the blood. If the kidneys did not remove them, these wastes would build up in the blood and damage the body.
    ::肾的作用是过滤血液和形成尿液; 尿液是人体排泄出的液体废物; 血液中的废物来自组织正常断裂,如组织和食物; 身体用食物作为能量; 身体从食物中提取所需的养分后,有些废物被吸收到血液中; 如果肾不去除,这些废物会积积聚在血液中,损害身体。

    Kidneys and Nephrons
    ::肾和肾

    The actual removal of wastes from the blood occurs in tiny units inside the kidneys called nephrons . Nephrons are the structural and functional units of the kidneys. A single kidney may have more than a million nephrons! This is further discussed in the Urinary System concept.
    ::实际从血液中清除的废物发生在肾脏内称为肾脏的微小单位中,内孔是肾的结构性和功能性单位,单肾可能有100多万个肾脏。

    A kidney showing anatomy, including nephrons, renal artery, and ureter.

    Each kidney is supplied by a renal artery and renal vein.
    ::每个肾脏都有肾动脉和肾静脉

    Kidneys and Homeostasis
    ::肾肾和足足症

    The kidneys play many vital roles in . They work with many other organ systems to do this. For example, they work with the to filter blood, and with the urinary system to remove wastes.
    ::肾脏在其中发挥着许多关键作用。它们与许多其他器官系统合作这样做。例如,它们与血液过滤系统合作,与尿道系统合作清除废物。

    The kidneys filter all the blood in the body many times each day and produce a total of about 1.5 liters of urine . The kidneys control the amount of , ions , and other substances in the blood by excreting more or less of them in urine. The kidneys also secrete hormones that help maintain homeostasis. Erythropoietin , for example, is a kidney hormone that stimulates bone marrow to produce red blood cells when more are needed. They also secrete renin, which regulates , and calcitriol, the active form of vitamin D , which helps maintain calcium for . The kidneys themselves are also regulated by hormones. For example, antidiuretic hormone from the hypothalamus stimulates the kidneys to produce more concentrated urine when the body is low on water.
    ::肾脏每天多次过滤体内的所有血液,并产生大约1.5升的尿液。肾脏通过在尿液中或多或少地排泄来控制血液中的离子和其他物质的数量。肾脏还分泌有助于保持软骨保持的荷尔蒙。例如,肾内激素是一种肾激素,在需要更多时刺激骨髓,以产生红细胞。它们还进行隐秘,调节,以及卡西里醇,即维他命D的活性形式。肾脏本身也受荷尔蒙管制。例如,在身体缺水时,极低的抗亚荷尔蒙刺激肾脏产生更集中的尿。

    Other Functions
    ::其他职能

    In addition to filtering blood and producing urine, the kidneys are also involved in maintaining the water level in the body, and regulating red blood cell levels and blood pressure.
    ::除了过滤血液和生产尿液外,肾脏还参与保持身体水位,调节红细胞水平和血压。

    • As the kidneys are mainly involved in the production of urine, they react to changes in the body’s water level throughout the day. As water intake decreases, the kidneys adjust accordingly and leave water in the body instead of helping remove it through the urine, maintaining the water level in the body.
      ::肾脏主要参与尿液生产,因此对身体水位的全天变化做出反应。 随着水摄入量的减少,肾脏也相应调整,将水留在体内,而不是帮助通过尿液取出,保持体内的水位。
    • The kidneys also need constant pressure to filter the blood. When the blood pressure drops too low, the kidneys increase the pressure. One way is by producing angiotensin, a blood vessel-constricting . This protein also signals the body to retain sodium and water. Together, the constriction of and retention of sodium and water help restore normal blood pressure.
      ::肾脏也需要不断的压力来过滤血液。当血压下降过低时,肾脏会增加压力。 一种方法是生产血管素, 一种血管抑制。 这种蛋白质也意味着身体保留钠和水。 钠和水的收缩和保留共同帮助恢复正常的血压。
    • When the kidneys don’t get enough oxygen, they send out a signal in the form of the hormone erythropoietin, which stimulates the bone marrow to produce more oxygen-carrying red blood cells.
      ::当肾脏得不到足够的氧气时,它们会发出荷尔蒙红血素的信号,刺激骨髓产生更多的含氧红细胞。

     

     

    Summary
    ::摘要

    • The kidneys maintain homeostasis by controlling the amount of water, ions, and other substances in the blood.
      ::肾通过控制血液中的水量、离子量和其他物质,保持了顺势。
    • Kidneys also secrete hormones that have other homeostatic functions.
      ::肾脏还分泌具有其他顺势功能的荷尔蒙。

    Review
    ::回顾

    1. What is the nephron? How many nephrons are in each kidney?
      ::肾脏里有多少个肾脏?
    2. Explain how the kidneys maintain homeostasis.
      ::解释一下肾脏是如何保持顺势的
    3. What is the role of antidiuretic hormone?
      ::抗亚尿荷尔蒙的作用是什么?