17.6 间接消化器官
章节大纲
-
Jaundiced Eyes
::死刑之眼Did you ever hear of a person looking at something or someone with a “jaundiced eye”? It means to take a negative view, such as envy, maliciousness, or ill will. The expression may be based on the antiquated idea that liver bile is associated with such negative emotions as these, as well as the fact that excessive liver bile causes jaundice, or yellowing of the and skin. Jaundice is likely a sign of a liver disorder or blockage of the duct that carries bile away from the liver. Bile contains waste products, making the liver an organ of excretion . Bile also has an important role in digestion , which makes the liver an accessory organ of digestion, too.
::你有没有听说过一个人在看什么或某个人身上有“被禁闭的眼睛”吗?这意味着要持负面观点,比如嫉妒、恶意或恶意。表达方式可能基于一个古老的观念,即肝脏胆量与这些负面情绪相关联,以及肝脏过大会导致黄化或皮肤黄化。黄化可能是肝脏紊乱的迹象,也可能是从肝脏中流出的管子堵塞。Bile含有废物产品,使肝脏成为排泄器官。Bile在消化中也扮演重要角色,使肝脏成为消化的辅助器官。What Are Accessory Organs of Digestion?
::什么是间接消化器官?Accessory organs of digestion are organs that secrete substances needed for the chemical digestion of food , but through which food does not actually pass as it is digested. Besides the liver, the major accessory organs of digestion are the gallbladder and pancreas . These organs secrete or store substances that are needed for digestion in the first part of the — the duodenum — where most chemical digestion takes place. You can see the three organs and their locations in the figure .
::消化器的切入器官是将食物化学消化所需的物质秘密起来的器官,但食物实际上不会随着消化而通过,除了肝脏外,消化的主要辅助器官是胆囊和胰腺,这些器官秘密或储存消化所需的物质在大部分化学消化的第一部分——二元——进行消化。你可以在图中看到这三种器官及其位置。The liver, gallbladder, and pancreas are the major accessory organs of digestion. In this figure, the pink tubular structure that starts at the lower stomach and wraps around the pancreas is the duodenum of the small intestine. This is where the accessory organs secrete their digestive substances.
::肝脏、胆囊和胰腺是消化的主要辅助器官。在这个图中,从下胃开始并环绕胰腺的粉色管状结构是小肠的二角。这是辅助器官分泌消化物质的地方。Liver
::升动器The liver is a vital organ located in the upper right part of the abdomen. It lies just below the diaphragm , to the right of the stomach . The liver plays an important role in digestion by secreting bile, but the liver has a wide range of additional functions unrelated to digestion. In fact, some estimates put the number of functions of the liver at about 500! A few of them are described below.
::肝脏是位于腹部右上部的重要器官,位于腹部右侧的隔膜下方。肝脏在通过隐蔽易碎体消化中起着重要作用,但肝脏具有与消化无关的多种其他功能。事实上,一些估计数字显示肝脏的功能约为500个。下面将介绍其中一些。Structure of the Liver
::肝脏结构The liver is a reddish brown, wedge-shaped structure. In adults, the liver normally weighs about 1.5 kg (3.3 lb). It is both the heaviest internal organ and the largest gland in the . The liver is divided into four lobes of unequal size and shape. Each lobe, in turn, is made up of lobules, which are the functional units of the liver. Each lobule consists of millions of liver , called hepatic cells (or hepatocytes). They are the basic metabolic cells that carry out the various functions of the liver.
::肝脏是红棕色、wedge形结构,在成年人中,肝脏通常重1.5公斤(3.3磅)。肝脏是体内最重的器官,也是最大腺。肝脏分为四个大小和形状不均的叶子。每个叶子由大叶组成,它们是肝脏的功能单位。每叶由几百万个肝脏组成,称为肝细胞(或肝细胞)。它们是基本代谢细胞,可以发挥肝脏的各种功能。As shown in the figure , the liver is connected to two large : the hepatic artery and the portal vein . The hepatic artery carries oxygen-rich from the aorta , whereas the portal vein carries blood that is rich in digested nutrients from the GI tract and wastes filtered from the blood by the spleen . The blood vessels subdivide into smaller arteries and capillaries, which lead into the liver lobules. The nutrients from the GI tract are used to build many vital biochemical compounds, and the wastes from the spleen are degraded and excreted.
::如图所示,肝脏与两大体系相连:肝血管动脉和入口静脉。肝血管动脉从动脉中携带富含氧气的血液,而入口静脉中携带的血液则含有大量来自GI道的消化养分和经脾脏过滤从血液中过滤出来的废物。血管分解成较小的动脉和血管,通向肝循环。GI道的养分被用于制造许多重要的生化化合物,而脾脏的废物则被降解和排出。The portal vein supplies the liver with wastes filtered out of the blood in the spleen, as well as nutrients from the gastrointestinal tract. Oxygen-rich blood enters the liver via the hepatic artery.
::口腔静脉为肝脏提供了从脾脏血液中过滤出来的废物,以及胃肠道的养分。Functions of the Liver
::肝脏的函数The main digestive function of the liver is the production of bile. Bile is a yellowish alkaline liquid that consists of , electrolytes, bile salts, and cholesterol, among other substances, many of which are waste products. Some of the components of bile are synthesized by hepatocytes. The rest are extracted from the blood.
::肝脏的主要消化功能是生成胆碱性黄液,包括电解液、胆碱盐和胆固醇等物质,其中许多是废物产品,而胆碱性成分的一些成分由肝细胞合成,其余部分从血液中提取。As shown in the figure , bile is secreted into small ducts that join together to form larger ducts, with just one large duct carrying bile out of the liver. If bile is needed to digest a meal, it goes directly to the duodenum through the common bile duct. In the duodenum, the bile neutralizes acidic chyme from the stomach and emulsifies fat globules into smaller particles (called micelles) that are easier to digest chemically by the lipase. Bile also aids with the absorption of vitamin K . Bile that is secreted when digestion is not taking place goes to the gallbladder for storage until the next meal. In either case, the bile enters the duodenum through the common bile duct shown in the figure.
::如图中所示,胆量被隐藏在小管子中,这些管子合在一起形成更大的管子,只有一条大管子,从肝脏中取出一个大管子。如果需要胆量来消化一顿饭,它直接通过共同的胆量管直接进入二角膜。在二角膜中,胆量中和胃酸性微粒,将脂肪球球块融化成小粒子(称为小鼠),这些小粒子更容易用唇酶进行化学消化。在不进行消化的情况下,维生素K.Bile的吸收也是一种辅助剂,在不进行消化的情况下,该剂会通过胆囊贮存到下一道饭。在这两种情况下,都通过图中显示的常见的胆量管进入二角。The common bile duct carries bile from both the liver and gallbladder to the duodenum. It is simply labeled “bile duct” in this figure.
::普通的卷发管从肝脏和胆囊都携带卷发器到二角膜。 此图中仅标有“ 卷发管 ” 。Besides its roles in digestion, the liver has many other vital functions.
::除了消化作用外,肝脏还有其他许多重要功能。-
The liver synthesizes glycogen from
glucose
and stores the glycogen as required to help regulate blood sugar levels. It also breaks down the stored glycogen to glucose and releases it back into the blood as needed.
::肝脏合成来自葡萄糖的甘油,并储存所需的甘油,帮助调节血糖水平,还将储存的甘油分解为葡萄糖,并按需要将其释放回血液。 -
The liver stores many substances in addition to glycogen, including
vitamins
A, D, B12, and K. It also stores the
minerals
iron and copper.
::肝脏除了储存甘油外,还储存许多物质,包括维生素A、D、B12和K。 肝脏还储存矿物铁和铜。 -
The liver synthesizes numerous
and many of the
amino acids
needed to make them. These proteins have a wide range of functions. They include fibrinogen, which is needed for blood clotting; insulin-like growth factor (IGF-1), which is important for
childhood
growth; and albumen, which is the most abundant protein in blood serum and functions to transport
fatty acids
and
steroid hormones
in the blood.
::肝脏合成了许许多多所需的氨基酸,这些蛋白质具有多种功能,包括血凝结所需的纤维素、对儿童成长很重要的胰岛素类生长系数(IGF-1)、以及血液血清中最丰富的蛋白质以及将脂肪酸和类固醇运入血液的功能。 -
The liver synthesizes many important
, including cholesterol, triglycerides, and lipoproteins.
::肝脏合成许多重要成分,包括胆固醇、三甘酸酯和脂蛋白。 -
The liver is responsible for the breakdown of many waste products and toxic substances. The wastes are excreted in bile or travel to the
, which excrete them in
urine
.
::肝脏造成许多废物和有毒物质的分解,废物排泄在粪便中,或被排泄到尿液中。
The liver is clearly a vital organ that supports almost every other organ in the body. Because of its strategic location and diversity of functions, the liver is also prone to many diseases, some of which cause loss of liver function. There is currently no way to compensate for the absence of liver function in the long term, although liver dialysis techniques can be used in the short term. An artificial liver has not yet been developed, so liver transplantation may be the only option for people with liver failure.
::肝脏显然是支撑人体几乎所有其它器官的重要器官,由于其战略位置和功能的多样性,肝脏也易患多种疾病,其中一些导致肝功能丧失,目前无法长期弥补肝功能的缺失,尽管肝透析技术可以在短期内使用,人工肝脏尚未开发,因此肝脏移植可能是肝衰竭者的唯一选择。Gallbladder
::Gallblader 圆形球The gallbladder is a small, hollow, pouch-like organ that lies just under the right side of the liver (see the figure ). It is about 8 cm (3.1 in.) long and shaped like a tapered sac, with the open end continuous with the cystic duct. The gallbladder stores and concentrates bile from the liver until it is needed in the duodenum to help digest lipids. After the bile leaves the liver, it reaches the gallbladder through the cystic duct. At any given time, the gallbladder may store between 30 and 60 mL (1-2 oz) of bile. A stimulated by the presence of fat in the duodenum signals the gallbladder to contract and force its contents back through the cystic duct and into the common bile duct to drain into the duodenum.
::胆囊是一种小的、空洞的、象邮袋的器官,刚好在肝脏右侧(见图)下方。它的长度约为8厘米(3.1英寸),形状像一个磁带沙囊,开口端与囊状管连在一起。胆囊储存并浓缩肝脏中的肉汁,直到二角需要用它来消化脂肪为止。在胆囊离开肝脏后,它通过囊状管到达胆囊中。任何时候,胆囊可能储存30至60毫升(1-2oz)的胆囊。在脂肪的推动下,胆囊将胆囊连接起来,通过囊状管和通气管将内的东西排入二角管。The biliary tract includes the liver, gallbladder, and the ducts that join them with the duodenum. It also includes the pancreas and the pancreatic duct, which enters the duodenum together with the common bile duct.
::底部包括肝脏、胆囊和与二甲苯胺结合的管子,还包括胰腺和胰腺管,它们与普通的胆管一起进入二甲苯胺。Pancreas
::胰腺The pancreas is a glandular organ that is part of both the and the . As shown in the figure , it is located in the abdomen behind the stomach, with the head of the pancreas surrounded by the duodenum of the small intestine. The pancreas is about 15 cm (6 in.) long, and it has two major ducts: the main pancreatic duct and the accessory pancreatic duct. Both of these ducts drain into the duodenum.
::胰腺是一种腺器官,它既是腺器官的一部分,也是腺器官的一部分。如图所示,它位于腹部后面的腹部,腹部被小肠的二角环环绕。胰腺长约15厘米(6英寸),有两条大管道:主胰岛素导管和附属胰岛素导管。这两种管道都排入二角管。Pancreatic digestive enzymes and bicarbonate travel to the duodenum through the pancreatic ducts. The main pancreatic duct joins with the common bile duct before the latter enters the duodenum.
::脉冲消化酶和双碳酸酯通过胰腺导管进入二核共聚物中,主要胰腺导管在进入二核共聚物中前与普通的脉冲连接。As an endocrine gland, the pancreas secretes several hormones, including insulin and glucagon , which circulate in the blood. The endocrine hormones are secreted by clusters of cells called pancreatic islets (or islets of Langerhans). As a digestive organ, the pancreas secretes many digestive enzymes and also bicarbonate, which helps neutralize acidic chyme after it enters the duodenum. The pancreas is stimulated to secrete its digestive substances when food in the stomach and duodenum triggers the release of endocrine hormones into the blood that reach the pancreas via the bloodstream. The pancreatic digestive enzymes are secreted by clusters of cells called acini, and they travel through the pancreatic ducts to the duodenum. In the duodenum, they help to chemically break down , proteins, lipids, and in chyme. The pancreatic digestive enzymes include:
::作为内分泌腺,胰腺分泌了几种激素,包括胰岛素和凝胶,这些激素在血液中流通。内分泌激素由称为胰岛素的细胞群(或Langerhans的小岛)分泌。作为消化器官,胰岛素分泌了许多消化酶,还有碳酸酯,这有助于在进入二聚苯之后中和酸性。当胃和二聚苯胺的食物导致内分泌激素释放进入通过血液流到达胰腺的血液中时,胰腺激素被分泌出来。胰岛素消化酶由称为丙尼的细胞群分泌而分泌,它们穿过胰岛素的气管。在二聚苯胺中,它们有助于化学分裂、蛋白质、脂类和外聚。胃消化酶包括:-
amylase
, which helps digest
starch
and other carbohydrates
::氨基酶,它有助于消化淀粉和其他碳水化合物 -
trypsin
and
chymotrypsin
, which help digest proteins
::催化素和希希莫氏素,有助于消化蛋白质 -
lipase
, which helps digest lipids
::脂脂类,有助于消化脂质 -
deoxyribonucleases
and
ribonucleases
, which help digest nucleic acids
::有助于消化核糖核酸的脱氧核糖核酸
Summary
::摘要-
Accessory organs of digestion are organs that secrete substances needed for the chemical digestion of food, but through which food does not actually pass as it is digested. The accessory organs include the liver, gallbladder, and pancreas. These organs secrete or store substances that are carried to the duodenum of the small intestine as needed for digestion.
::消化器是分泌食物化学消化所需的物质,但食物实际上不会随着消化而经过的器官。辅助器官包括肝脏、胆囊和胰腺。这些器官是分泌或储存在消化所需的小肠二元的物质。 -
The liver is a large organ in the abdomen that is divided into lobes and smaller lobules, which consist of metabolic cells called hepatic cells, or hepatocytes. The liver receives oxygen in blood from the aorta through the hepatic artery. It receives nutrients in blood from the GI tract and wastes in blood from the spleen through the portal vein.
::肝脏是腹部的一个大器官,分为叶子和小叶囊,由代谢细胞组成,称为肝细胞,或肝细胞,肝脏通过肝动脉从动脉从动脉血液中接收氧气,从GI道血液中接收营养素,从脾脏到门静脉血液中接收废物。 -
The main digestive function of the liver is the production of the alkaline liquid called bile. Bile is carried directly to the duodenum by the common bile duct or to the gallbladder first for storage. Bile neutralizes acidic chyme that enters the duodenum from the stomach, and also emulsifies fat globules into smaller particles (micelles) that are easier to digest chemically.
::肝脏的主要消化功能是生产碱性液体,称为Bile,Bile直接通过普通的Bile导管或首先储存的胆囊携带到duodenum。Bile中性从腹部进入duodenum的酸性旋律,还将脂肪球泡乳化成较容易化学消化的较小颗粒(微粒)。 -
Other vital functions of the liver include regulating blood sugar levels by storing excess sugar as glycogen, storing many vitamins and minerals, synthesizing numerous proteins and lipids, and breaking down waste products and toxic substances.
::肝脏的其他关键功能包括调节血糖水平,将多余的糖储存为甘油,储存许多维他命和矿物质,综合多种蛋白和脂质,分解废物和有毒物质。 -
The gallbladder is a small pouch-like organ near the liver. It stores and concentrates bile from the liver until it is needed in the duodenum to neutralize chyme and help digest lipids.
::胆囊是肝脏附近一个小的象邮袋的器官,它储存和浓缩肝脏的粘液,直到二角膜需要它来中和和消化脂液。 -
The pancreas is a glandular organ that secretes both endocrine hormones and digestive enzymes. As an endocrine gland, the pancreas secretes insulin and glucagon to regulate blood sugar. As a digestive organ, the pancreas secretes digestive enzymes into the duodenum through ducts. Pancreatic digestive enzymes include amylase (starches) trypsin and chymotrypsin (proteins), lipase (lipids), and ribonucleases and deoxyribonucleases (RNA and DNA).
::胰腺是分泌内分泌激素和消化酶的腺器官,作为内分泌腺,胰腺分泌胰岛素和凝胶以调节血糖,作为消化器官,胰腺分泌通过管道将消化酶注入二聚苯乙烯,胰腺消化酶包括氨基酶(恒星)、丁丙烯酸(蛋白质)、脂(脂质)和核糖核酸和脱氧核糖核酸(RNA和DNA)。
Review
::回顾1. Name three accessory organs of digestion. How do these organs differ from digestive organs that are part of the GI tract?
::1. 列出三个消化的辅助器官:这些器官与作为GI草皮一部分的消化器官有何不同?2. Describe the liver and its blood supply.
::2. 描述肝脏及其血液供应情况。3. Explain the main digestive function of the liver.
::3. 解释肝脏的主要消化功能。4. Besides its role as a digestive organ, what other vital functions does the liver serve ?
::4. 除了作为消化器官的作用外,肝脏还能发挥什么其他关键功能?5. What is the gallbladder? How does it aid in digestion in the duodenum?
::5. 什么是胆囊?它如何帮助二元共聚物消化?6. Which two body systems include the pancreas? What type of secretions does the pancreas release as part of each body system?
::6. 哪些两种体系包括胰腺?作为每个体系的一部分,胰腺会释放何种分泌物?7. List pancreatic enzymes that work in the duodenum, along with the substances they help digest.
::7. 列出在二甲苯中起作用的胰腺酶,以及它们有助于消化的物质。8. What are two substances produced by accessory organs of digestion that help neutralize chyme in the small intestine? Where are they produced?
::8. 有助于中和小肠道中微粒的消化器辅助器官产生的两种物质是什么?它们在哪里生产?9. Jaundice is caused by...
::9. 糖尿病是由...a. lack of bicarbonate in the small intestine
::a. 小型肠道缺乏碳酸碳酸碳酸碳酸碳酯b. excess insulin being secreted by the pancreas
::b. 胰腺素隐藏的过量胰岛素c. lack of trypsin in the small intestine
::c. 小肠胃缺乏试金素c. excess bile in the liver
::c. 肝脏中多余的胆量10. People who have their gallbladder removed sometimes have digestive problems after eating high-fat meals. Why do you think this happens?
::10. 胆囊被摘除的人有时在吃高脂肪饭后有消化问题,你认为为什么会发生这种情况?11. True or False: The liver is a gland.
::11. 真实或假:肝脏是腺。12. True or False: Substances secreted by the pancreas enter into the duodenum from the common bile duct.
::12. 真实或假物质:由胰腺秘密的物质从共同的粘液管进入二元。13. True or False: Bile contains wastes.
::13. 真实的或虚假的:Bile含有废物。14. Ribonuclease is a
_____________.
::14. Ribonuclease是aa. enzyme
::a. 酶b. nucleic acid
::b. 核酸c. hormone
::c. 荷激素d. type of ribosome
::d. 排卵体型15. Which accessory organ of digestion synthesizes cholesterol?
::15. 哪些消化器从属器官合成胆固醇?Explore More
::探索更多Check out this video to learn about hepatitis:
::校对:PortnoyWatch this video to learn more about jaundice and why it is common in newborn babies:
::以及为什么黄麻在新生儿中很常见: -
The liver synthesizes glycogen from
glucose
and stores the glycogen as required to help regulate blood sugar levels. It also breaks down the stored glycogen to glucose and releases it back into the blood as needed.
