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  • 肾

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    Kidneys on the Menu
    ::菜单上的肾上腺

    Pictured here amidst a bed of mixed veggies is a steak and kidney pudding. More often made into a pie, this savory dish is a British favorite. When kidneys are on a menu, they typically come from sheep, pigs, or cows. In these (as in the human animal), kidneys are the main organs of excretion .
    ::在一块混合蔬菜的床上,这里的图象是牛排和肾脏布丁。 更常见的是,这个美味的菜盘是英国最喜爱的馅饼。 当肾脏在菜单上时,它们通常来自绵羊、猪或牛。 在这些(和人类动物一样)中,肾脏是主要的排泄器官。

    Location of the Kidneys
    ::基德尼人的位置

    The two bean-shaped kidneys are located high in the back of the abdominal cavity, one on each side of the spine. Both kidneys sit just below the diaphragm , the large muscle that separates the abdominal and thoracic cavities. As you can see in the figure, the right kidney is slightly smaller and lower than the left kidney. The right kidney is behind the liver , and the left kidney is behind the spleen . The location of the liver explains why the right kidney is smaller and lower than the left.
    ::两个豆形的肾脏位于腹腔背部高处,脊椎两侧各一个。两个肾脏都位于隔膜下方,大肌肉隔开腹部和胸腔。如图所示,右肾小于左肾,右肾小于左肾。右肾在肝脏后面,左肾在脾脏后面。肝脏的位置解释了右肾脏为何小于左肾的原因。

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    This classic illustration of the abdominal cavity provides a view of the internal organs from the back of the body. It clearly shows the locations of the right and left kidney, as well as the large blood vessels that connect the kidneys to the body’s main artery (aorta) and vein (inferior vena cava). The ureter exiting each kidney is also shown in the diagram.
    ::腹腔的这一典型示例提供了身体后部器官的视图。 它清楚地显示了右和左肾的位置,以及连接肾脏与身体主动脉(动脉)和血管(脉动)的大型血管。 图表中还显示了每个肾脏的尿素。

    Kidney Anatomy
    ::肾肾学解剖学

    The shape of each kidney gives it a convex side and a concave side. You can see this clearly in the detailed diagram of kidney anatomy shown . The concave side is where the renal artery enters the kidney, as well as where  the renal vein and ureter leave the kidney. This area of the kidney is called the hilum . The entire kidney is surrounded by tough fibrous tissue — called the renal capsule — which, in turn, is surrounded by two layers of protective, cushioning fat.
    ::每个肾脏的形状给它一个曲线侧面和一个曲线侧面。您可以从肾解剖的详细图表中清楚地看到这一点。结剖侧面是肾脏动脉进入肾脏的地方,以及肾血管和尿素离开肾脏的地方。肾脏的这个区域被称为。整个肾脏周围都是坚硬的纤维组织 — — 叫做肾囊 — — 而肾囊则被两层防护性、缓冲脂肪所包围。

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    This diagram shows the location and relative size of the two kidneys, as well as the internal structure of each kidney.
    ::该图显示两个肾的位置和相对大小,以及每个肾的内部结构。

    Internally, each kidney is divided into two major layers: the outer renal cortex and the inner renal medulla (see diagram above). These layers take the shape of many cone-shaped renal lobules, each containing renal cortex surrounding a portion of medulla called a renal pyramid. Within the renal pyramids are the structural and functional units of the kidneys, the tiny nephrons . Between the renal pyramids are projections of cortex called renal columns. The tip, or papilla, of each pyramid empties urine into a minor calyx (chamber). Several minor calyces empty into a major calyx, and the latter empty into the funnel-shaped cavity called the renal pelvis, which becomes the ureter as it leaves the kidney.
    ::在内部,每个肾脏分为两大层:外肾皮层和内肾内肾膜(见上文图)。这些层形形形形形许多锥形肾结壳,每个层内都含有肾上皮层环绕一个叫做肾金字塔的部分。在肾金字塔内,肾上金字塔是肾的结构和功能单位,即微小的肾。在肾金字塔之间,对皮层的预测称为肾柱。每个金字塔的尾部,或papilla,将每个金字塔的内脏尿液变成一个小的calex(Calyx) 。一些小圆柱形形形形,空入一个主要的圆柱形体,而后者空入一个流球形的圆形腔,称为肾结骨,随着肾的离开而成为尿液。

    Renal Circulation
    ::彩环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环环

    The renal circulation is an important part of the kidney’s primary  function of filtering waste products from the . Blood is supplied to the kidneys via the renal arteries. The right renal artery supplies the right kidney, and the left renal artery supplies the left kidney. These two arteries branch directly from the aorta , which is the largest artery in the body. Each kidney is only about 11 cm (4.4 in.) long, and has a mass of just 150 grams ( 5.3 oz), yet it receives about ten percent of the total output of blood from the heart. Blood is filtered through the kidneys about 20 times each hour, 24 hours a day, day after day.
    ::肾循环是肾脏过滤废品的主要功能的重要组成部分。血液通过肾动脉供应给肾脏。右肾动脉供应右肾,左肾动脉供应左肾。这两条动脉系直接来自血管,这是体内最大的动脉。每个肾脏只有大约11厘米(4.4英寸)长,质量只有150克(5.3 oz),但它得到的血液总产值的10%左右。血液每天每天每天24小时通过肾脏过滤大约20次。

    As indicated in the figure , each renal artery carries blood with waste products into the kidney. Within the kidney, the renal artery branches into increasingly smaller arteries that extend through the renal columns between the renal pyramids. These arteries, in turn, branch into arterioles that penetrate the renal pyramids. Blood in the arterioles passes through nephrons, the structures that actually filter the blood. After blood passes through the nephrons and is filtered, the clean blood moves through a network of venules that converge into small veins. Small veins merge into increasingly larger ones, and ultimately into the renal vein, which carries clean blood away from the kidney to the inferior vena cava .
    ::如图所示,每个肾动脉都携带血液和废弃产品进入肾脏。肾脏内,肾动脉分支进入越来越小的动脉,穿过肾金字塔之间的肾柱。这些动脉反过来又变成切入肾金字塔的动脉。动脉中的血液通过肾脏,这种结构实际上过滤血液。血液通过肾脏和过滤后,干净的血液通过凝结成小血管的毒液网络。小血管会逐渐变大,最终进入肾血管,从肾脏流出干净的血液,到下等血管。

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    The renal artery and renal vein carry blood to and from the kidney, respectively. As blood passes through a nephron within the kidney, it is filtered. Substances filtered from the blood are eventually collected in a tubule (collecting duct).
    ::肾动脉和肾静脉分别含有肾和肾的血。当血液通过肾内一个肾时,就会过滤。从血液中过滤的物质最终会收集到一个管状管(收集管子 ) 。

    Nephron Structure and Function
    ::神经结构和功能

    The illustration above gives an indication of the complex structure of a nephron. The nephron is the basic structural and functional unit of the kidney, and each kidney typically contains at least a million of them. As blood flows through a nephron, many materials are filtered out of the blood, needed materials are returned to the blood, and the remaining materials form urine. Most of the waste products removed from the blood and excreted in urine are byproducts of metabolism . At least half of the waste is urea, a waste product produced by catabolism. Another important waste is uric acid, produced in catabolism.
    ::上文的插图说明了一个肾的复杂结构。肾是肾的基本结构和功能单位,每个肾通常至少含有其中的100万个。由于血液通过一个肾脏流动,许多材料从血液中过滤,需要的材料被退回到血液中,其余的材料构成尿液。从血液中取出并在尿液中排出的大部分废物是新陈代谢的副产品。至少一半的废物是尿素,这是一种由催化物产生的废物。另一个重要的废物是尿酸,以催化物的形式产生。

    Components of a Nephron
    ::内环的构件

    The diagram shows in greater detail the components of a nephron. Each nephron is composed of an initial filtering component that consists of a network of capillaries called the glomerulus (plural, glomeruli), which is surrounded by a space within a structure called   Bowman’s capsule . Extending from Bowman’s capsule is the renal tubule . The proximal end (nearest Bowman’s capsule) of the renal tubule is called the proximal convoluted (coiled) tubule . From here, the renal tubule continues as a loop (known as the loop of Henle), which in turn becomes the distal convoluted tubule. The latter finally joins with a collecting duct. As you can see in the diagram, arterioles surround the total length of the renal tubule.
    ::图表更详细地显示了肾脏的成分。 每一个肾脏都是由最初的过滤元件组成, 由被称为球状的毛细线( 圆形, 球状) 的毛细线组成, 环绕在叫做鲍曼的胶囊结构内的空间中。 从鲍曼的胶囊中延伸出来的是肾囊管。 肾质管管的近端( 鲍曼 的胶囊) 叫做 蛋白状( 腐烂的) 管。 从这里看, 肾轮管继续作为环状( 被称为亨勒环 ) , 转而成为卷状管。 后者最终与卷状管相连接。 从图中可以看到, 卷状管的总长度周围有动画。

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    This model of an individual nephron shows each of the structures that are involved in filtering blood, returning needed materials to blood, or excreting wastes that form urine. The arrows indicate the direction in which fluids flow through the nephron.
    ::这种单个肾模型显示了参与过滤血液、将所需材料还给血液或排泄形成尿液的废物的每一种结构。箭头显示流体流经肾脏的方向。

    Function of a Nephron
    ::内环函数

    The simplified diagram of a nephron in the figure shows how the nephron functions. Blood enters the nephron through an arteriole called the afferent arteriole . Next, some of the blood passes through the capillaries of the glomerulus. Any blood that doesn’t pass through the glomerulus — as well as blood after it passes through the glomerular capillaries — continues on through an arteriole called the efferent arteriole . The efferent arteriole follows the renal tubule of the nephron, where it continues playing a role  in nephron functioning.
    ::该图中肾脏的简化图显示了肾脏的功能。血液通过一个叫“远端动脉”的动脉进入肾脏。接下来,一些血液通过球状体的毛细膜穿透。任何没有穿过球状体的血液 — — 以及经过球状动脉的血液 — — 继续通过一个叫做“远端动脉 ” 的动脉。 肾动脉沿着肾脏的肾管而行,在肾脏功能中继续发挥作用。

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    This diagram of a nephron shows the parts of the nephron where different stages of nephron function take place. These stages are filtration, reabsorption, secretion, and excretion.
    ::肾形图显示了肾上腺函数的不同阶段发生的部分。这些阶段是过滤、再吸附、分解和排泄。

    Filtration
    ::过滤

    As blood from the afferent arteriole flows through the glomerular capillaries, it is under pressure. Because of the pressure, and solutes are filtered out of the blood and into the space made by Bowman’s capsule. This is the filtration stage of nephron function. The filtered substances — called filtrate — pass into Bowman’s capsule, and from there into the proximal end of the renal tubule. At this stage, filtrate includes water, salts, organic solids (such as nutrients), and waste products of metabolism (such as urea).
    ::作为从远处的动脉中流出的血液,它正在承受压力。 由于压力和溶液被从血液中过滤出来,并被过滤到鲍曼的胶囊中。 这就是肾功能的过滤阶段。 过滤的物质 — — 叫做过滤剂 — — 被传递到鲍曼的胶囊中,然后从那里传到肾管的近端。 在现阶段,过滤包括水、盐、有机固体(如营养素)和新陈代谢的废品(如尿素 ) 。

    Reabsorption and Secretion
    ::重新吸收和保密

    As filtrate moves through the renal tubule, some of the substances it contains are reabsorbed from the filtrate back into the blood in the efferent arteriole (via peritubular capillaries). This is the reabsorption stage of nephron function. About two-thirds of the filtered salts and water, and all of the filtered organic solutes (mainly glucose and amino acids) are reabsorbed from the filtrate by the blood in the peritubular capillaries. Reabsorption occurs mainly in the proximal convoluted tubule and the loop of Henle.
    ::随着过滤通过肾管,其所含的一些物质从过滤器中重新吸收回流到动脉中的血液中。这是肾功能的再吸附阶段。大约三分之二的过滤盐类和水,以及所有过滤的有机溶液(主要是葡萄糖和氨基酸)都重新吸收到经过滤的血管中的血液中。再吸附主要发生在近身卷动管和Henle循环中。

    At the distal end of the renal tubule, some additional reabsorption generally occurs. This is also the region of the tubule where other substances from the blood are added to the filtrate in the tubule. The addition of other substances to the filtrate from the blood is called secretion . Both reabsorption and secretion in the distal convoluted tubule are largely under the control of endocrine that maintain of water and mineral salts in the blood. These hormones work by controlling what is reabsorbed into the blood from the filtrate and what is secreted from the blood into the filtrate to become urine. For example, parathyroid hormone causes more calcium to be reabsorbed into the blood and more phosphorus to be secreted into the filtrate.
    ::在肾管的分解端,通常会发生一些额外的再吸附。这也是在管子区域,将血液中的其他物质添加到管子的过滤器中。从血液过滤器中添加的其他物质称为分泌物。在分解管管的分泌物中,重新吸附和分泌都主要由内分泌控制,内分泌保持血液中的水和矿盐。这些荷尔蒙通过控制从过滤器中血液中重新吸收的成分和从血液中分离出来的血液中分离出来的成分成为尿液而起作用。例如,除虫菊激素使更多的钙被重新吸收到血液中,而更多的磷则被隐藏在过滤器中。

    Collection of Urine and Excretion
    ::尿和排泄物的收集

    By the time the filtrate has passed through the entire renal tubule, it has become the liquid waste known as urine. Urine empties from the distal end of the renal tubule into a collecting duct . From there, the urine flows into increasingly larger collecting ducts. As urine flows through the system of collecting ducts, more water may be reabsorbed from it. This will occur in the presence of antidiuretic hormone from the posterior pituitary gland . This hormone makes the collecting ducts permeable to water, allowing water molecules to pass through them into capillaries by , while preventing the passage of ions or other solutes. As much as 75 percent  of the water may be reabsorbed from urine in the collecting ducts, making the urine more concentrated.
    ::当过滤器穿过整个肾管管时,它就变成了被称为尿液的液体废物。从肾管管管的阴端的尿液排入一个收集管。从那里,尿液流到日益扩大的收集管管中。随着尿液通过收集管系统流出,更多的水可能会从中重新吸收。这将会发生在后天自流腺的抗二尿荷尔蒙面前。这种荷尔蒙使收集的气管渗透到水中,使水分子能够通过水管穿透气管进入囊中,同时防止离子或其他溶液的通过。高达75%的水可能从收集管中的尿液中重新吸收,使尿液更加集中。

    Urine finally exits the largest collecting ducts through the renal papillae. It empties into the renal calyces, and finally into the renal pelvis. From there, it travels through the ureter to the urinary bladder for eventual excretion from the body. An average of roughly  1.5 liters of urine is excreted each day. Normally, urine is yellow or amber in color (see the photo ). The darker the color, generally speaking, the more concentrated the urine is.
    ::尿液最终通过肾上腺素排出最大的收集管道。 它会插入肾上腺素, 最终进入肾上腺素骨。 从那里, 它会穿过尿液到尿囊, 以便最终从身体排出。 平均每天排出大约1.5升尿液。 通常尿液是黄色的或黄色的( 参见照片 ) 。 一般而言, 尿液的颜色越暗, 尿液就越集中 。

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    Fresh urine is typically yellow or amber in color.
    ::新鲜的尿液通常是黄色的,或彩色的琥珀。

    Other Functions of the Kidneys
    ::肾脏的其他功能

    Besides filtering blood and forming urine for excretion of soluble wastes, the kidneys have several vital functions in maintaining body-wide homeostasis. Most of these functions are related to the composition or volume of urine formed by the kidneys. The kidneys must maintain the proper balance of water and salts in the body, normal , and the correct range of blood pH. Through the processes of absorption and secretion by nephrons, more or less water, salt ions, acids, or bases are returned to the blood or excreted in urine, as needed,8 to maintain homeostasis.
    ::除了过滤血液和形成尿液以排泄可溶性废物外,肾在保持整个身体的耐久性方面有若干关键功能,这些功能大多与肾构成的尿的成分或体积有关,肾必须保持体内的水和盐份的适当平衡、正常和血液的正确范围pH值。 通过肾的吸收和分泌过程,或多或少于水、盐离子、酸或碱子,必要时将血液或尿液排出,8 以保持耐久性。

    Blood Pressure Regulation
    ::血压调节条例

    The kidneys do not control homeostasis all alone. As indicated above, endocrine hormones are also involved. Consider the regulation of blood pressure by the kidneys. Blood pressure is the pressure exerted by blood on the walls of the arteries. The regulation of blood pressure is part of a complex system, called the renin-angiotensin-aldosterone system. This system regulates the concentration of sodium in the blood to control blood pressure.
    ::如上文所述,肾脏不能单独控制软体保持,内分泌荷尔蒙也包括在内。考虑由肾对血压进行调节。血压是指动脉壁上的血压。血压调节是一个复杂的系统的一部分,称为renin-angiotensin-aldosterone系统。这个系统调节血液中钠的浓度,以控制血压。

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    This diagram summarizes the processes that occur in the regulation of blood pressure by the renin-angiotensin-aldosterone system. The final step on the far right occurs in the nephrons and collecting ducts of the kidneys, where aldosterone stimulates increased reabsorption of sodium and water into the blood.
    ::该图总结了在调控血压过程中通过 renin-angiotensin-aldosterone 系统产生的过程,极右端的最后一步出现在肾脏的肾脏中,在肾脏中,阿多斯特龙刺激了对钠和水的再吸附。

    The renin-angiotensin-aldosterone system is put into play when the concentration of sodium ions in the blood falls lower than normal. This causes the kidneys to secrete an called renin into the blood. It also causes the liver to secrete a protein called angiotensinogen. Renin changes angiotensinogen into a proto-hormone called  angiotensin I. This is converted to angiotensin II by an enzyme (angiotensin-converting enzyme) in lung capillaries.
    ::当血液中的钠离子浓度低于正常水平时,就启用了异丁烯-亚丁-异狄氏酮系统。这导致肾脏在血液中分泌一种叫作累因的内分泌,还导致肝脏分泌一种叫作血管素的蛋白质。Renin将血管素转化为一种原激素,叫做血管素I。通过肺膜酶(angiotensin-可转换酶)将其转换为血管素II。

    Angiotensin II is a potent hormone that causes arterioles to constrict. This, in turn, increases blood pressure. Angiotensin II also stimulates the secretion of the hormone aldosterone from the adrenal cortex. Aldosterone causes the kidneys to increase the reabsorption of sodium ions and water from the filtrate into the blood. This returns the concentration of sodium ions in the blood to normal. The increased water in the blood also increases blood volume and blood pressure.
    ::Angiotensin II是一种导致动脉收缩的强效激素,这反过来又会增加血压。 Angiotensin II 也刺激肾上皮层分泌激素藻酮。 Aldosterone 导致肾脏增加从过滤液中吸收离子钠和水到血液中。 这使血液中的钠离子浓度恢复到正常状态。 血液中增加的水也会增加血量和血压。

    Other Kidney Hormones
    ::其他肾其他荷尔蒙

    H ormones other than renin are also produced and secreted by the kidneys. These include calcitriol and erythropoietin .
    ::雷宁以外的荷尔蒙也由肾脏产生和隐藏,包括卡西里醇和红血素。

    • Calcitriol is secreted by the kidneys in response to low levels of calcium in the blood. This hormone stimulates uptake of calcium by the intestine, thus raising blood levels of calcium.
      ::这种激素刺激肠胃吸收钙,从而提高钙的血液水平。
    • Erythropoietin is secreted by the kidneys in response to low levels of oxygen in the blood. This hormone stimulates erythropoiesis, which is the production of red blood cells in bone marrow . Extra red blood cells increase the level of oxygen carried in the blood.
      ::Erythropoietin 由肾脏密密,以回应血液中氧气含量低的情况,这种激素刺激了骨髓红细胞,即骨髓中的红细胞。额外的红细胞增加了血液中氧气的含量。

    Feature: Human Biology in the News
    ::特著:《新闻》中的人类生物学

    Kidney failure is a complication of common disorders including mellitus and hypertension . Almost half a million Americans have end-stage kidney disease and must either receive a donated kidney or have frequent hemodialysis, a medical procedure in which the blood is artificially filtered through a machine. Transplant generally results in  better outcomes than hemodialysis, but demand for organs far outstrips the supply. At any given time, more than 100 thousand people in the U.S. are on a waiting list for a kidney transplant, but each year fewer than 20 thousand receive them. Every day, 13 Americans die while waiting for a donor kidney.
    ::肾衰竭是常见疾病(包括宫颈和高血压)的复杂因素。 近50万美国人患有晚期肾病,必须接受捐赠肾脏,或者经常接受血液透析,这是一种医疗程序,通过机器人工过滤血液。 移植的结果通常优于血液透析,但对器官的需求远远超出供给。 在任何特定时间,超过10万美国人都在等待肾脏移植,但每年只有不到2万美国人得到肾脏移植。 每天有13个美国人在等待捐赠肾脏时死亡。

    For the past decade, Dr. William Fissell, a kidney specialist at Vanderbilt University, has been working to create an implantable part-biological and part-artificial kidney. Using microchips like those used in computers, he has produced an artificial kidney small enough to implant in the patient’s body in place of the failed kidney. According to Dr. Fissell, the artificial kidney is “... a bio- hybrid device that can mimic a kidney to remove enough waste products, salt, and water to keep a patient off [hemo] dialysis .”
    ::过去十年来,Vanderbilt大学肾学专家William Fissell博士一直在致力于创建可移植的局部生物和局部造肾。 他利用计算机中所使用的微小芯片生产出一个人工肾脏,这个肾脏小得足以植入病人的身体,以代替衰竭的肾脏。 据Fissell博士说,人工肾是“...一个可以仿造肾脏以去除足够废弃产品、盐和水的生物混合装置 ” 。

    The filtration system in the artificial kidney consists of a stack of 15 microchips. Tiny pores in the microchips act as a scaffold for the growth of living kidney that can mimic the natural functions of the kidney. The living cells form a membrane to filter the patient’s blood as a biological kidney would, but with less risk of rejection by the patient’s immune system , because they are embedded within the device. The new kidney doesn’t need a power source, because it uses the natural pressure of blood flowing through arteries to push the blood through the filtration system. A major part of the design of the artificial organ was devoted to fine tuning the fluid dynamics so blood flows through the device without clotting.
    ::人工肾脏的过滤系统由15个微芯片组成。微芯片中的微孔是活性肾脏生长的支架,可以模仿肾脏的自然功能。活性细胞形成膜以过滤病人的血液,作为生物肾脏,但较少被病人的免疫系统排斥的风险,因为它们嵌入了该装置。 新肾不需要动力源,因为它利用动脉血液流动的自然压力将血液推入过滤系统。 人工器官设计的主要部分是精细调整液体动态,以便血液在没有凝血块的情况下通过该装置流动。

    Because of the potential life-saving benefits of the device, t he implantable kidney was given fast-track approval for testing in people by the U.S. Food and Drug Administration. The artificial kidney is expected to be tested in pilot trials by 2018. Dr. Fissell says he has a long list of patients eager to volunteer for the trials.
    ::由于该装置可能带来拯救生命的好处,美国食品和药品管理局给予可移植肾脏快速批准在人体内进行检测,预计到2018年,人工肾脏将在试点试验中进行检测。 Fissell博士说,他有很长的急于自愿接受测试的病人名单。

    Summary
    ::摘要

    • The two bean-shaped kidneys are located high in the back of the abdominal cavity on either side of the spine. A renal artery connects each kidney with the aorta, and transports unfiltered blood to the kidney. A renal vein connects each kidney with the inferior vena cava and transports filtered blood back to the circulation.
      ::两个豆形的肾脏位于脊椎两侧腹腔背部的高处,一个肾动脉连接每个肾和动脉,将未过滤的血液输送到肾脏,一个肾静脉连接每个肾脏和低等的藤,并将经过过滤的血液运回循环。
    • The kidney has two main layers involved in the filtration of blood and formation of urine: the outer cortex and inner medulla. At least a million nephrons — which are the tiny functional units of the kidney — span the cortex and medulla. The entire kidney is surrounded by a fibrous capsule and protective fat layers.
      ::肾在血液过滤和尿液形成方面有两个主要层次:外皮层和内膜,至少100万个肾——它们是肾的微小功能单位——横跨皮层和体积,整个肾被一个纤维胶囊和保护性脂肪层包围。
    • As blood flows through a nephron, many materials are filtered out of the blood, needed materials are returned to the blood, and the remaining materials are used to form urine.
      ::随着血液通过肾脏流动,许多材料被从血液中过滤出来,所需材料被退回血液,其余材料被用于形成尿液。
    • In each nephron, the glomerulus and surrounding Bowman’s capsule form the unit that filters blood. From Bowman’s capsule, the material filtered from blood (called filtrate) passes through the long renal tubule. As it does, some substances are reabsorbed into the blood, and other substances are secreted from the blood into the filtrate, finally forming urine. The urine empties into collecting ducts, where more water may be reabsorbed.
      ::在每一个肾脏中,球体和鲍曼的胶囊周围形成过滤血液的单位。 从鲍曼的胶囊中,血液过滤的材料(称为过滤器)通过长肾管穿透。 诚然,有些物质被重新吸收到血液中,而其他物质则被从血液中隐藏到过滤器中,最终形成尿液。 尿液排入管道收集管道,那里可能有更多的水重新吸收。
    • The kidneys control homeostasis with the help of endocrine hormones. T he kidneys, for example, are part of the renin-angiotensin-aldosterone system that regulates the concentration of sodium in the blood to control blood pressure. In this system, the enzyme renin secreted by the kidneys works with hormones from the liver and adrenal gland to stimulate nephrons to reabsorb more sodium and water from urine.
      ::肾脏在内分泌激素的帮助下控制了顺势。例如,肾脏是调控血液中钠浓度以控制血压的伦宁-angiotensin-aldosterone系统的一部分。在这个系统中,肾脏秘密的酶与肝脏和肾上腺激素合作,刺激肾脏重新吸附更多的钠和尿液的水。
    • The kidneys also secrete endocrine hormones, including calcitriol — which helps control the level of calcium in the blood — and erythropoietin, which stimulates bone marrow to produce red blood cells.
      ::肾脏还分泌内分泌激素,包括卡西里醇——它有助于控制血液中的钙含量——和骨质素,它刺激骨髓产生红细胞。

    Review
    ::回顾

    1. Where are the kidneys located?
    ::1. 肾脏在哪里?

    2. Contrast the renal artery and renal vein.
    ::2. 对比肾动脉和肾静脉。

    3. Describe the structure of the kidney.
    ::3. 描述肾结构。

    4. Identify the functions of a nephron.
    ::4. 确定甲状腺的功能。

    5. Describe in detail what happens to fluids (blood, filtrate, and urine) as they pass through the parts of a nephron.
    ::5. 详细描述流体(血液、过滤液和尿液)穿过肾脏部分时发生的情况。

    6. Use the example of the renin-angiotensin-aldosterone system to illustrate how the kidneys control homeostasis, with the help of endocrine hormones.
    ::6. 以renin-angiotensin-aldosterone系统为例,说明肾脏如何在内分泌激素的帮助下控制自闭症。

    7. Identify two endocrine hormones secreted by the kidneys, along with the functions they control.
    ::7. 查明肾脏隐藏的两种内分泌激素及其控制功能。

    8. Put the following structures in order of how urine flows out of the kidney, from the earliest to the latest:
    ::8. 将以下结构排列为从最早到最晚如何从肾脏流出尿液的顺序:

    collecting ducts; renal tubule; renal pelvis; renal calyces
    ::收集管道; 肾管管; 肾骨盆; 肾阴囊

     

    9. Name two regions in the kidney where water is reabsorbed.
    ::9. 列出肾脏中两个重新吸收水的区域。

     

    10. True or False:  Once the filtrate enters the renal tubule, no substances are added to it.
    ::10. 真实或假:过滤器一旦进入肾管管,就不会增加任何物质。

     

    11. True or False:  Some substances are reabsorbed in the distal end of the renal tubule.
    ::11. 真实或假物质:有些物质被重新吸收到肾管的断裂端。

     

    12. Is the blood in the glomerular capillaries more or less filtered than the blood in the peritubular capillaries? Explain your answer.
    ::12. 球状毛皮上的血是否比临产毛皮上的血过滤的多或少?解释一下你的回答。

     

    13. How many nephrons are there per kidney?
    ::13. 每肾有多少个肾?

    a. one
    ::a. 1

    b. 13
    ::b. 13个

    a. at least one thousand
    ::a. 至少千个

    a. at least one million
    ::a 至少100万

     

    14. What do you think would happen if  blood flow to the kidneys is blocked ?
    ::14. 如果进入肾脏的血液被阻塞,你认为会发生什么情况?

     

    15. The loop of Henle is part of the______________________.
    ::15. Henle的循环是其中的一部分。

    a. glomerulus
    ::a. 球状

    b. renal tubule
    ::b. 肾管管

    c. collecting duct
    ::c. 收集管道

    d. ureter
    ::d. 尿素

    Explore More
    ::探索更多

    Another researcher working on an implantable kidney is surgeon Anthony Atala. In this fascinating TED talk, he shows how a 3D printer that uses living cells can potentially print out a transplantable kidney. Dr. Atala has already used similar technology to engineer a replacement bladder for a young patient, who is introduced in the video below.
    ::另一个研究可移植肾脏的研究者是外科外科医生安东尼·阿塔拉。在这个令人着迷的TED演讲中,他展示了使用活细胞的三维打印机如何能够打印出可移植的肾脏。阿塔拉博士已经使用类似的技术为一位年轻的病人设计了替换膀胱,并在下面的视频中介绍。

    In medicine, diuretics are used to treat heart failure, liver cirrhosis, hypertension, and various kidneys diseases. Learn more here:
    ::在医学中,亚尿症被用于治疗心脏病、肝硬化、高血压和各种肾病。