医学英语教程-生物医学Unit6A课文翻译

医学英语教程医学英语教程- -生物医学生物医学 Unit 6 Reading A The Kidney and Its Working UnitThe Kidney and Its Working Unit 肾及其工作单位肾及其工作单位 For many diners, eating tender, pale green shoots of asparagus is a pleasurable springtime event, but the gastronomic experience has a peculiar sequel：The next time they urinate ,even if just 20 minutes after eating, they notice the characteristic scent of asparagus. A chemical in the food crosses the gut ,enters the bloodstream, is filtered out by the kidneys, and appears in the urine with amazing speed. Actually, the chemical is acted on no faster than any other compound. The kidneys are simply marvelsatprocessingbodyfluidsandfilteringouttheurea;the sodium ,potassium ,or chloride ions ;and the glucose, water ,and other materials that need to be excreted. The key to a kidney s rapid functioning lies in its complicated internal structure and in the effcient plumbing system of which it is a part. 对许多用餐者来说， 吃到浅绿鲜嫩的芦笋是春季的一大享受，但享用完这种 美食后会有一个奇特的后续： 即使饭后仅 20 分钟,人们便会在上厕所时注意到尿 液中有芦笋特殊的气味。芦笋中的某种化学物质以万分惊人的速度穿过肠子,进 入循环的血液,并被肾脏过滤出来,最后出现在尿液中。 事实上，这一化学物的作 用并不比其他化合物更快些。起到加速体液循循环并过滤出尿素,钠、钾、氯离 子、葡萄糖、水及一切需排泄的这些惊叹不已的作用的是肾脏。肾脏能快捷地发 挥作用的关键就在于其复杂的内部结构， 以及它作为其中一部分的高效率管道系 统。 The Kidneys and Other Organs of the Excretory SystermThe Kidneys and Other Organs of the Excretory Systerm 肾脏和排泄系统的其他器官肾脏和排泄系统的其他器官 It is sometimes stated that urination is our most compelling bodily function. You will probably agree if you have ever been hungry, tired ,cold ,and had a full bladder simultaneously and can recall the order in which you addressed those needs. This urgency has to do with the necessary waste removal role of the excretory system and with the system s particular anatomy. 人们有时说排尿是我们身体最急迫的功能。如果你曾经有过饥饿、疲倦、寒 冷及膀胱满胀等感觉并能回忆起你处理这些身体需要的顺序， 你就会同意以上那 种说法。这种急迫感与排泄系统必要的排废作用和该系统特别的解剖结构有关。 The main organs of the excretory system are the two plump, dark red, crescent- shaped kidneys, each about the size of an adult s fist and located high in the abdominal cavity behind the stomach and the liver. For each kidney to carry out its vital blood-filtering activities ,it must receive a large, steady flow of blood. 排泄系统的主要器官是两个圆满的、暗红色的、月牙状的肾脏。每个约有成 人拳头大小, 位于腹腔上部胃、肝的后面。因为肾脏担负过滤血液的重要任务， 所以必须接收到强大持续的血流。 This it does through the renal arteries, twin branches directly off the body s main blood vessel, or aorta. Cleansed blood then leaves each kidney in large renal blood vein that drains into the body s largest vein. As the kidneys filter and remove excess water and waste substances from the blood, these materials collect as a concentrated urine in a central cavity in each kidney, then flow down a long tube called a ureter. The two ureters dump urine into a single storage sac, the urinary bladder, which in an adult can hold about 500 ml (a pint) of fluid. The bladder can distend to hold a bit more, but when it is full, it causes considerable pressure on nearby nerves and a feeling of urgency that can temporarily eclipse all other concerns. During urination ,the urine exits the body th