18.2 行使机关
Section outline
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Getting Rid of Wastes
::清理废物The dual chimneys on this house are one of the ways that the inhabitants of the home get rid of the wastes they produce. The chimneys expel waste gases that are created when they burn fuel in their furnace or fireplace. Think about the other wastes that people create in their homes and how we dispose of them . Solid trash and recyclables may go to the curb in a trash can or recycling bin for pick up and transport to a landfill or recycling center. Waste from sinks, showers, toilets, and the washing machine goes into a main sewer pipe and out of the house to join the community’s sanitary sewer system.
::这座房子里的双重烟囱是住家居民摆脱自己产生的废物的方式之一。烟囱将燃烧炉炉或壁炉燃料时产生的废气排出。想想人们在家中创造的其他废物,以及我们如何处置这些废物。 固体垃圾和可回收垃圾可能进入垃圾桶的路障,或者回收垃圾箱,以便回收垃圾,然后运到垃圾填埋场或回收中心。 汇、淋浴、厕所和洗衣机产生的废物进入主下水道管道,然后从房屋中排出,加入社区的卫生下水道系统。Like a busy home, your body also produces a lot of wastes that must be eliminated. Like a home, the way your body gets rid of wastes depends on the nature of the waste products. Some wastes are gases, some are solids, and some are in a liquid state. Getting rid of body wastes is called excretion , and there are a number of different organs of excretion in the human body.
::就像一个繁忙的家一样,你的身体也产生许多必须消除的废物。像家一样,你的身体摆脱废物的方式取决于废物产品的性质。有些废物是气体,有些是固体,有些是液态的。清除人体废物被称为排泄物,在人体中有许多不同的排泄器官。Excretion
::自由裁量Excretion is the process of removing wastes and excess water from the body. It is an essential process in all living things, and it is one of the major ways the human body maintains . It also helps prevent damage to the body. Wastes include by-products of metabolism — some of which are toxic — and other non-useful materials, such as used up and broken down components. Some of the specific waste products that must be excreted from the body include carbon dioxide from , ammonia and urea from catabolism, and uric acid from catabolism.
::排泄是从身体中清除废物和多余水的过程,是所有生物中的一个基本过程,是人体保持的主要方法之一,也有助于防止对身体的损害,废物包括新陈代谢的副产品(其中一些是有毒的)和其他不使用的材料,例如废旧和碎裂的成分,必须从身体中排出的某些具体的废物产品包括来自催化的二氧化碳、氨和尿素,以及来自催化分离的酸酸。Excretory Organs
::特派机关Organs of excretion include the skin, liver , , lungs , and (see the figure ). Together, these organs make up the excretory system . They all excrete wastes, but they don’t work together in the same way that organs do in most other body systems. Each of the excretory organs “does its own thing” more-or-less independently of the others, but all are necessary to successfully excrete the full range of wastes from the human body.
::排泄器官包括皮肤、肝脏、肺和(见图 ) 。 这些器官共同组成了排泄系统。 它们都是排泄废物,但它们并不像其他器官系统那样共同工作。 每个排泄器官“自己做自己的事 ” , 都比其他器官更独立,但为了成功地将所有废物从人体中排出,它们都是必要的。Internal organs of excretion are identified in this general illustration of human anatomy. They include the liver, large intestine, lungs, and kidneys.
::在人类解剖的这一一般性示例中确认了内分泌器官,包括肝脏、大肠、肺和肾脏。Skin
::皮肤The skin is part of the integumentary system , but it also plays a role in excretion through the production of sweat by sweat glands in the dermis . Although the main role of sweat production is to cool the body and maintain temperature homeostasis, sweating also eliminates excess water and salts, as well as a small amount of urea. When sweating is copious, as in the figure , ingestion of salts and water may be helpful to maintain homeostasis in the body.
::皮肤是内脏系统的一部分,但它也通过皮肤中汗腺的出汗而起到排泄作用,尽管出汗生产的主要作用是冷却身体和保持温度的顺常态,但出汗也消除了多余的水和盐类以及少量尿素。 当出汗如图所示多时,摄入盐和水可能会有助于保持体内的顺常态。The purpose of sweat production is mainly to cool the body and prevent overheating, but it also contributes to excretion.
::出汗生产的目的主要是冷却身体和防止过热,但也有助于排泄。Liver
::升动器The liver (shown ) has numerous major functions, including secreting bile for digestion of , synthesizing many proteins and other compounds, storing glycogen and other substances, and secreting endocrine . In addition to all of these functions, the liver is a very important organ of excretion. The liver breaks down many substances in the , including toxins. For example, the liver transforms ammonia — a poisonous by-product of protein catabolism — into urea, which is filtered from the blood by the kidneys and excreted in urine . The liver also excretes in its bile the protein bilirubin, a byproduct of hemoglobin catabolism that forms when red blood cells die. Bile travels to the and is then excreted in feces by the large intestine.
::肝脏(皮肤)具有许多主要功能,包括隐蔽细胞,供消化,合成许多蛋白质和其他化合物,储存甘蓝和其他物质,并隐匿内分泌。除了所有这些功能外,肝脏是十分重要的排泄器官。肝脏分解包括毒素在内的许多物质。例如,肝脏将氨这一蛋白化的有毒副产物转化成尿素,由肾脏从血液中过滤,在尿液中排出。肝脏还将蛋白菌排出,这是红血细胞死亡时血红蛋白的代谢的副产物。肝脏通向乳房,然后排入大肠的粪便中。The liver and large intestine are two of the major organs of excretion.
::肝脏和大肠是排泄的两个主要器官。Large Intestine
::大型不适The large intestine is an important part of the and the final organ in the gastrointestinal tract (see figure above). As an organ of excretion, its main function is to eliminate solid wastes that remain after the digestion of food and the extraction of water from indigestible matter in food waste. The large intestine also collects wastes from throughout the body. B ile secreted into the gastrointestinal tract, for example, contains the waste product bilirubin from the liver. Bilirubin is a brown pigment that gives human feces their characteristic brown color.
::大肠是胃肠道中一个重要和最后器官的重要组成部分(见上图),作为排泄器官,其主要功能是消除食物消化和从食物废物中提取稀释物质产生的水后留下的固体废物。大肠也从全身收集废物。例如,在胃肠道中隐藏的肠道含有肝脏中的Bilirubin废物产品。Bilirubin是一种棕色的色素,它给人类带来其特有的褐色。Lungs
::肺肺The lungs are part of the (shown in the figure ), but they are also important organs of excretion. They are responsible for the excretion of gaseous wastes from the body. The main waste gas excreted by the lungs is carbon dioxide, which is a waste product of cellular respiration in throughout the body. Carbon dioxide is diffused from the blood into the air in the tiny air sacs called alveoli in the lungs (shown in the inset diagram in the figure). By expelling carbon dioxide from the blood, the lungs help maintain acid-base homeostasis. In fact, it is the pH of blood that controls the rate of . Water vapor is also picked up from the lungs and other organs of the respiratory tract as the exhaled air passes over their moist linings, and the water vapor is excreted along with the carbon dioxide. Trace levels of some other waste gases are exhaled, as well.
::肺部是肺部的一部分(如图所示),但也是重要的排泄器官。它们负责从身体中排出气体废物。肺中排出的主要废气是二氧化碳,这是整个身体细胞呼吸过程中产生的废物。二氧化碳从血液中扩散到肺部中称为肺泡的微小空气囊中的空气中的空气中。通过将二氧化碳从血液中排出,肺部有助于保持酸基原温。事实上,正是血液的pH值控制了呼吸道的肺和其他器官的速率。随着排出的空气通过湿气管,从肺部和其他器官中取出水蒸气,而水蒸气与二氧化碳一起被排出。其他一些废气的痕量也被排出。The alveoli are the functional structures in the lungs where gaseous wastes enter the air from the blood.
::气态废物从血液进入空气的肺部功能结构。Kidneys
::肾The paired kidneys are often considered the main organs of excretion. The primary function of the kidneys is the elimination of excess water and wastes from the bloodstream by the production of the liquid waste known as urine . The main structural and functional units of the kidneys are tiny structures called nephrons . Nephrons filter materials out of the blood, return to the blood what is needed, and excrete the rest as urine. As shown in the diagram , the kidneys are organs of the , which also includes the ureters , bladder , and urethra — organs that transport, store, and eliminate urine, respectively.
::肾脏的主要功能是通过生产被称为尿液的液体废物,从血液中消除多余的水和废物,肾脏的主要结构和功能单位是微小的结构结构,称为肾脏,内弗龙从血液中过滤材料,恢复所需的血液,将其余作为尿液排出,如图所示,肾脏是尿道的器官,其中也包括尿囊、膀胱和尿尿——分别运输、储存和消除尿液的器官。The urinary system consists of two kidneys (1), two ureters (2), the urinary bladder (3), and the urethra (4).
::尿道系统由两个肾脏(1)、两个尿管(2)、尿囊(3)和尿道(4)组成。By producing and excreting urine, the kidneys play vital roles in body-wide homeostasis. T hey maintain the correct volume of extracellular fluid, which is all the fluid in the body outside of cells, including the blood and lymph . The kidneys also maintain the correct balance of salts and pH in extracellular fluid. In addition, the kidneys function as , secreting hormones into the blood that control other body processes. You can read much more about the kidneys in the concept Kidneys .
::肾脏通过生产和排出尿液,在全身的软体保持功能中发挥着关键作用,它们保持正确的细胞外液体积,这是细胞外体体体内的所有液体,包括血液和淋巴;肾脏还保持了细胞外体液中盐和pH的正确平衡;此外,肾脏的作用是将荷尔蒙分泌到血液中,以控制其他身体过程。你可以更多地阅读Kidneys概念中的肾脏。Summary
::摘要-
Excretion is the process of removing wastes and excess water from the body. It is an essential process in all living things and a major way the human body maintains homeostasis.
::排泄是从身体中清除废物和过量水的过程,是所有生物中的一个基本过程,也是人体保持顺势的主要方法。 -
Organs of excretion include the skin, liver, large intestine, lungs, and kidneys. All of them excrete wastes, and together they make up the excretory system.
::排泄器官包括皮肤、肝脏、大肠、肺和肾,全部排出废物,共同构成排泄系统。 -
The skin plays a role in excretion through the production of sweat by sweat glands. Sweating eliminates excess water and salts, as well as a small amount of urea, a byproduct of protein catabolism.
::皮肤通过血汗腺的出汗在排泄中起到作用,湿润消除了多余的水和盐类以及少量尿素,后者是蛋白质催化的副产品。 -
The liver is a very important organ of excretion. The liver breaks down many substances in the blood, including toxins. The liver also excretes bilirubin — a waste product of hemoglobin catabolism — in bile. Bile then travels to the small intestine, and is eventually excreted in feces by the large intestine.
::肝脏是一种非常重要的排泄器官,肝脏分解了血液中包括毒素在内的许多物质,肝脏还排泄了大肠胃的粪便。 肝脏也是血红蛋白催化物的废品。 肝脏随后进入小肠道,最终排出大肠胃的粪便。 -
The main excretory function of the large intestine is to eliminate solid waste that remains after food is digested and water is extracted from the indigestible matter. The large intestine also collects and excretes wastes from throughout the body, including bilirubin in bile.
::大型肠道的主要排泄功能是消除在食物消化和从不可消化的物质中抽取水后留下的固体废物,大型肠道还从全身收集和排出废物,包括桶里的比里鲁宾。 -
The lungs are responsible for the excretion of gaseous wastes, primarily carbon dioxide from cellular respiration in cells throughout the body. Exhaled air also contains water vapor and trace levels of some other waste gases.
::肺对气体废物的排泄负有责任,主要是整个身体细胞细胞呼吸产生的二氧化碳,吸入的空气还含有水蒸气和其他一些废气的痕量。 -
The paired kidneys are often considered the main organs of excretion. Their primary function is the elimination of excess water and wastes from the bloodstream by the production of urine. The kidneys contain tiny structures called nephrons that filter materials out of the blood, return to the blood what is needed, and excrete the rest as urine. The kidneys are part of the urinary system, which also includes the ureters, urinary bladder, and urethra.
::配对肾脏通常被视为排泄的主要器官,其主要功能是通过生产尿液从血液中消除多余的水和废物,肾脏含有微小结构,称为肾脏,将材料从血液中过滤出来,恢复到所需的血液,并将其余部分排出作为尿液,肾脏是尿系统的一部分,也包括尿管、尿囊和尿囊。
Review
::回顾1. What is excretion, and what is its significance?
::1. 什么是权宜之计,其意义何在?2. Identify human organs of excretion. What do all of them have in common?
::2. 查明人类自理器官:所有器官的共同点是什么?3. What role does the skin play in excretion?
::3. 皮肤在排泄中起什么作用?4. Describe the excretory functions of the liver.
::4. 描述肝脏的排泄功能。5. What are the main excretory functions of the large intestine?
::5. 大型肠道的主要排泄功能是什么?6. What do the lungs excrete?
::6. 肺排泄物是什么?7. Describe the primary function of the kidneys. What role do nephrons play in this function?
::7. 描述肾的主要功能:甲状腺在这一功能中起什么作用?8. List organs of the urinary system.
::8. 尿道系统器官清单。9. Describe the physical states in which the wastes from the human body are excreted.
::9. 描述排泄人体废物的物理状态。10. True or False: The small intestine is one of the major organs of the excretory system.
::10. 真实或假:小肠是排泄系统的主要器官之一。11. True or False: Uric acid is produced from the breakdown of nucleic acids.
::11. 真酸或假酸:铀酸是核酸分解后产生的。12. Give one example of why ridding the body of excess water is important.
::12. 举一个例子说明为什么清除身体多余的水很重要。13. Describe three ways in which excess water is excreted from the body.
::13. 说明从身体排出多余水的三种方式。14. What gives feces its brown color? Why is that substance produced?
::14. 是什么让粪便染上棕色的?为什么生产这种物质?Explore More
::探索更多Unlike lizards, we can't regenerate limbs, but we can regenerate our liver! Learn more here:
::不像蜥蜴,我们不能再生四肢, 但我们可以再生我们的肝脏!Sport drinks claim to replenish electrolytes and help hydrate you more than water, but are they really healthy? Check out this video to learn more:
::体育饮料声称补充电解液和帮助你补充水水,而不是水,但是它们真的健康吗? -
Excretion is the process of removing wastes and excess water from the body. It is an essential process in all living things and a major way the human body maintains homeostasis.
