医学教学课件：消化系统

1、 All the body systems depend on the digestive system. For the good health and energy. 由于消化系统能为由于消化系统能为 身体提供能量，保身体提供能量，保 持身体健康，所以持身体健康，所以 身体内的其他系统身体内的其他系统 都依赖着消化系统！都依赖着消化系统！ The gross food material that we consume is not instantaneously, converted into flesh. Through the special process it is convert

2、ed into several substances which are absorb by the blood and distributed through out the body. This process is called digestion. 我们所摄取的食物并非立即转化为组织，我们所摄取的食物并非立即转化为组织， 而是通过特殊的步骤转化为不同成分，这而是通过特殊的步骤转化为不同成分，这 些成分被血液吸收并输送到身体的每一个些成分被血液吸收并输送到身体的每一个 地方，这个过程被称为消化。地方，这个过程被称为消化。 ALIMENTARY CANAL消化道消化道 This canal

3、 from the mouth to the anus is 9 meters long. This constitutes the digestive system.从口腔到肛门整从口腔到肛门整 个消化道长个消化道长9米，这个构成了消化系统。米，这个构成了消化系统。 Its main parts are 1.Mouth, 口腔口腔 2.Pharynx, 咽咽 3.Esophagus, 食道食道 4.Stomach, 胃胃 1.Small intestine, 小肠小肠 5.Large intestine, 大肠大肠 6.Anus. 肛门肛门 Accessory digestive organ

4、s are connected to the main system by a series of ducts: 附属于主系统的消化器官由一连串的管道相连附属于主系统的消化器官由一连串的管道相连 1.Salivary Glands, 唾液腺唾液腺 2.The Pancreas, 胰胰 3.The Liver 肝肝 4.Gall Bladder.胆囊胆囊 Mechanical breakdown begins in the mouth by chewing (teeth) and actions of the tongue. （口腔的机械咀嚼）（口腔的机械咀嚼） Then just Chemic

5、al breakdown of starch by production of salivary amylase from the salivary glands. （唾液的化学消化）（唾液的化学消化） Salivary glands （唾液腺）（唾液腺） Present in the mouth produce a secretion, which mixes the food to form a fine paste. These glands are 2 below and front of ears (Parotid Glands 腮腺腮腺) 2 below the jaw (Subm

6、andibular下颌腺下颌腺) 2 below the tongue (Sublingual 舌下腺舌下腺) This mixture of food and saliva is then pushed into the pharynx and esophagus. The esophagus is a muscular tube whose muscular contractions (peristalsis) propel food to the stomach.（食管通过肌肉收缩蠕（食管通过肌肉收缩蠕 动，将食物输送到胃部）动，将食物输送到胃部） Stomach is a long,

7、hollow bag which can hold quite some quantity of food. It close by a valve. It produces gastric juices, which mix the food and churns it. Among the gastric juices are pepsin, hydrochloric acid and rennin. The first two break the food into different constituents, while the last gives solid form to li

8、quid for example, it curdle the milk, taken by the person. 胃是可以盛载足够食物的长形的胃是可以盛载足够食物的长形的 囊状结构。它通过阀门来控制囊状结构。它通过阀门来控制 的，并通过分泌胃酸混合和搅的，并通过分泌胃酸混合和搅 拌食物。胃酸的组成成分为胃拌食物。胃酸的组成成分为胃 蛋白、盐酸和凝乳酶。前两个蛋白、盐酸和凝乳酶。前两个 胃酸成分是将食物消化为不同胃酸成分是将食物消化为不同 的成分，最后的一个成分能够的成分，最后的一个成分能够 将液体物质固化。例如：凝乳将液体物质固化。例如：凝乳 酶能够将人所摄取的牛奶凝化。酶能够将人所摄取的

9、牛奶凝化。 Water and other fluids remain in the stomach for only few minute and then reach duodenum . Solids which escape being made into a pulp are subjected to a powerful process at the mouth of the duodenum. Here, contraction waves keep grinding food continuously and from time to time, the door to the

10、 duodenum opens up and the crushed food enter it. At this place, the secretions of stomach, liver pancreas and colon glands namely gastric juice, bile and pancreatic juices mix with the food. 水和其他液体只在胃部停留几分钟后便快速的到达水和其他液体只在胃部停留几分钟后便快速的到达 十二指肠。十二指肠。 固态物质被转化为浆状，被有力的推入十二指肠的固态物质被转化为浆状，被有力的推入十二指肠的 入口。入口。

11、小肠的收缩起伏偶尔会发出食物研磨的声音，因此小肠的收缩起伏偶尔会发出食物研磨的声音，因此 十二指肠的通道会打开同时压碎食物将其推入。十二指肠的通道会打开同时压碎食物将其推入。 在此处，胃、肝脏、胰腺和结肠的分泌物分别为胃在此处，胃、肝脏、胰腺和结肠的分泌物分别为胃 酸、胆汁、胰液。它们与食物混合在一起。酸、胆汁、胰液。它们与食物混合在一起。 The liver produces and sends bile to the small intestine via the hepatic duct, The gall bladder stores excess bile for release a

12、t a later time. We can live without our gall bladders, in fact many people have had theirs removed. 肝脏分泌胆汁。通过肝脏管肝脏分泌胆汁。通过肝脏管 到达小肠到达小肠 胆囊存储后来产生的过剩的胆囊存储后来产生的过剩的 胆汁胆汁 我们可以在移除胆的情况下我们可以在移除胆的情况下 生存生存 The pancreas sends pancreatic juice, which neutralizes the food, to the small intestine through the pancre

13、atic duct. The islets secrete the hormones insulin胰岛素 and glucagon胰 高血糖素, which regulate blood glucose levels. D i a b e t e s r e s u l t s f r o m inadequate levels of insulin. 输送胰液，分解食物，输送胰液，分解食物， 通过胰腺管将胰液输通过胰腺管将胰液输 送到小肠送到小肠. 分泌胰岛素、胰高血分泌胰岛素、胰高血 糖素，它们调节血糖糖素，它们调节血糖 水平。水平。 糖尿病是因为胰岛素糖尿病是因为胰岛素 分泌不足分泌不

14、足 Final digestion of proteins and carbohydrates must occur. The small intestine is the major site for digestion and absorption of nutrients. The small intestine is up to 6 meters long and is 2- 3 centimeters wide. The upper part, the duodenum十二指肠, is the most active in digestion. Secretions from the

15、 liver and pancreas are used for digestion in the duodenum. 蛋白质和碳水化合物最终消化。蛋白质和碳水化合物最终消化。 小肠是消化和吸收的主要场所。人的小肠长小肠是消化和吸收的主要场所。人的小肠长 约约56m，23厘米宽，小肠上部分有十二厘米宽，小肠上部分有十二 指肠，在消化过程中非常活跃，肝胆的分泌指肠，在消化过程中非常活跃，肝胆的分泌 物在十二指肠得到利用。物在十二指肠得到利用。 The large intestine is made up by The colon, Cecum, Appendix, Rectum. Materia

16、l in the large intestine is mostly indigestible residue and liquid. The large intestine performs functions: 1) Recovery of water and electrolytes from digested food; 2) Formation and storage of feces; and Water, salts, and vitamins are absorbed, and rest of the material goes towards the kidney and g

17、et collected in the rectum. It is excreted from the anus. 大肠的组成部分：结肠大肠的组成部分：结肠 盲肠盲肠 阑尾阑尾 存在于大肠的物质主要是无法消化的残渣和液存在于大肠的物质主要是无法消化的残渣和液 体体 大肠的主要功能是大肠的主要功能是 进一步吸收粪便中的水分、电解质和其他物质进一步吸收粪便中的水分、电解质和其他物质 （如氨、胆汁酸等），（如氨、胆汁酸等）， 形成、贮存和排泄粪便。形成、贮存和排泄粪便。 Regulation of Appetite 食欲调节食欲调节 The hypothalamus in the brain has

18、 two centers controlling hunger. 大脑中的下丘脑有两个大脑中的下丘脑有两个 调控饥饿的中枢调控饥饿的中枢 One is the appetite center,摄食中枢摄食中枢 The other the satiety center.餍足中枢餍足中枢 The digestion of food is complete in about 17 18 hours. The food is broken up into different constituents and distributed throughout the body. To keep the digestive system toned, cleansing processes, posture and breathing practices are ne