ChapterDigestionandAbsorption消化与吸收PPT课件

1、Chapter 5 Digestion and Absorption (消化与吸收消化与吸收)第1页/共72页Digestion (消化): The break-down process whereby the structurally complex foodstuffs of the diet are converted into smaller absorbable units by the enzymes produced within the digestive system ( (食物在消化道内被分解为小分子物质的过程) ) Mechanical digestion (机械性消化)

2、 ) Chemical digestion (化学性消化) )第2页/共72页 Absorption (吸收): The process that the smaller absorbable units of digestion get across the alimentary tract mucosa and come into blood or lymph. ( (食物经消化后通过消化道粘膜进入血液或淋巴的过程) )第3页/共72页Section1 Structure of Digestive Tract(消化管的结构消化管的结构)Intracellular digestion (胞内

3、消化胞内消化) Extracellular digestion (胞外消化胞外消化) 第4页/共72页1.Human Digestive Tract (人的消化管) 粘膜层： 上皮 上皮下层 粘膜肌层 粘膜下层 组织结构 (Submucous layer) 环行肌 胃部是三层 Smooth muscle 内斜,中环,外纵 纵行肌 浆膜 : C.T (Serous membrane) (Tissue structure) (Mucous layer)第5页/共72页2.The Innervation of Digestive Tract (消化管的神经支配消化管的神经支配) Extrinsic

4、NS & Intrinsic NS 第6页/共72页Sympathetic nerve (交感N ): The subdivision of the autonomic nervous system that dominates in “fight-or-flight” emergency or stressful situations and perpares the body for strenuous physical activity. (源自 T5 T10 & L1 L2在腹神经节和肠系膜上下N节换元) 第7页/共72页运动及分泌内在N元第8页/共72页 副：延髓背核

5、 疑核 运动及分泌第9页/共72页Myenteric plexus (肌间肌间N丛丛) Submucous plexus (粘膜下粘膜下N丛丛) Intrinsic plexus (内在N丛)： 包括感觉、中间、运动神经元构成一个完整 且相对独立的整合系统 第10页/共72页Section 2 The Movement and Regulation of Digestive Tract(消化管的运动及调节消化管的运动及调节) The movement of digestive tract (消化道的运动消化道的运动): Mastication (咀嚼咀嚼) Deglutition (吞咽吞咽)

6、 Gastrointestinal movement (胃肠运动胃肠运动)第11页/共72页Reflex (反射): Any response that occurs automatically without conscious effort. (在NS的参与下对刺激的规律性应答) Reflex arc (反射弧): The components of a reflex arc include a receptor, afferent pathway, integrating center, efferent pathway, and effector. (感受器 传入N N中枢 传出N 效

7、应器 )第12页/共72页1. Gastric movement (胃的运动) (1)Receptive relaxation(胃的容受性舒张) Definition: food stimulate the receptors in pharynx and esophagus, through vagus nerve arouse relaxation of fundus and body of stomach muscle. (食物刺激咽、食管等处感受器经迷走神经反射性引起胃底、胃体肌舒张) significance第13页/共72页(2)Tonic contraction (紧张性收缩紧张

8、性收缩)(3)Peristalsis (蠕动蠕动)Gastric BER (胃的基本电节律胃的基本电节律):It stems from longitudinal muscle of greater curvature, 35 times per minutes, amplitude is about 515 mv.(起源于胃大弯的纵行肌层，每分钟35次，振幅约515 mv )第14页/共72页 Function of peristalsis (蠕动) ： Lead to ample mixing of chyme and digestive juice, this is facilitated

9、 for chemical digestion. 使食糜与消化液充分混合，利于化学性消化 Mill food (mechanical digestion) 磨碎食物 (即机械性消化) Push chyme 推进食糜 第15页/共72页2.Gastric Emptying and Its Regulation (胃的排空及其控制胃的排空及其控制)Definition: The process that food enter into duodenum from stomach.(食物由胃排入12指肠的过程) (1)(1)胃排空胃排空 (gastric emptying) 第16页/共72页Emp

10、tying velocity (排空速度)：Sugarproteinfat;Sparse, thin, isosmotic quick (稀、细、等渗 快) (反之则慢)第17页/共72页(2) Regulation of gastric emptying (胃排空的调控胃排空的调控) Entogastric factors accelerate emptying (胃内因素促进排空胃内因素促进排空)： Entogastric food（Nr） (胃内食物) Gastrin （Hr） (胃泌素) 第18页/共72页Factors of duodenum inhibit emptying (12

11、脂肠因素抑制排空)： Gastrointestinal reflex（Nr）(肠胃反射) Enterogastrone （Hr） (肠抑胃素)第19页/共72页Emptying process(排空过程排空过程) )： Entogastric food(胃内食物胃内食物) ) emptying stopped (排空停排空停止止)motility of the stomach (胃运动胃运动) 胃运动胃运动 幽门括约肌舒张幽门括约肌舒张 幽门括约肌收缩幽门括约肌收缩 胃内压胃内压1212指肠内压指肠内压N (肠胃反射)H (肠抑胃素)肠内胃酸被中和食物被消化吸收 第20页/共72页3. The

12、 movements of small intestine (小肠的运动小肠的运动)(1)Tonic contraction (紧张性收缩紧张性收缩) Functions： Maintain basic pressure (维持基础压力维持基础压力) The basis of movements (是肠运动的基础是肠运动的基础) Fix and keep shape of small intestine (维持小肠的位置形状维持小肠的位置形状)第21页/共72页 (2)Segmentation contraction (分节运动分节运动) 第22页/共72页Functions： It can

13、lead to ample mixing of chyme and digestive juice, this is facilitated for chemical digestion. (使食糜与消化液充分混合，利于化学性消化) It can accelerate close contact of chyme and intestinal wall ,this is facilitated for absorption. (使食糜与肠壁紧密接触，利于吸收)第23页/共72页 It can press intestinal wall, accelerate blood and lymph c

14、ircumfluence. (挤压肠壁而促进血液、淋巴回流) (3)Peristalsis (蠕动) Peristalsis function : push chyme (推进食糜)第24页/共72页(4)Large intestinal movement and defecation (大肠运动和排便大肠运动和排便)The movement forms of large intestine (大肠运动形式大肠运动形式) 1)袋状往返运动袋状往返运动 2)分节或多袋推进运动分节或多袋推进运动 3) Peristalsis (蠕动蠕动)(mass peristalsis,集团蠕动集团蠕动) 第2

15、5页/共72页 Brain stem , cerebral cortex (脑干、大脑皮层脑干、大脑皮层) S2-S4直肠牵张直肠牵张R 内括约肌松驰Defecation reflex (排便反射)外括约肌松驰第26页/共72页(5)Regulation of digestive tract (消化管运动的调节消化管运动的调节)Electrical activity (电活动电活动) BER APNerve factors (神经因素神经因素) Sympathetic nerve (-) gastrointestinal movement 交感N (-) 胃肠运动 Vagus nerve (+

16、) gastrointestinal movement 迷走N (+) 胃肠运动第27页/共72页Intraparietal nerve plexus (壁内N丛) : Regulating gastrointestinal movement (调节胃肠运动)Cerebral cortex(大脑皮层) : Interest for food effects digestion. Psychogenic enterorrhea (对食物的好恶对消化的影响 精神性腹泻)第28页/共72页 3. Humoral factors (体液因素体液因素) ): Gastrointestinal hormo

17、ne (主胃肠激素主胃肠激素):): 抑胃肽NEmovementmovement第29页/共72页Section 3 The Secretion and Regulation of Digestive Juice (消化液的分泌及调节消化液的分泌及调节)1.The secretion of saliva (唾液的分泌唾液的分泌)第30页/共72页(1)The characters 、components and functions of saliva (唾液性质与成分与作用) ) Moisten , dissolve food (湿润、溶解食物) clean, protect mouth ca

18、vity (清洁、保护口腔) lubricate , hydrolyze amylum , kill bacteria (润滑 水解淀粉 杀菌)第31页/共72页(2) The regulation of salivary secretion (唾液分泌的调节唾液分泌的调节) Double excitation effect of sympathesis nerve and parasympathesis nerve (交感与副交感双重兴奋作用) Conditioned reflex (条件反射) Unconditioned reflex (非条件反射)第32页/共72页2. Gastric

19、secretion (胃液的分泌胃液的分泌) (1)Characters ,components and functions of gastric juice (胃液胃液的性质、成分和作用的性质、成分和作用) ) 无色透明，无色透明，第33页/共72页 Pepsinogen (胃蛋白酶原胃蛋白酶原) chief cell secretion (主细胞分泌主细胞分泌) ) +第34页/共72页 Mucus and HCO3HCO3- - (粘液与碳酸氢盐粘液与碳酸氢盐)胃粘液-碳酸氢盐屏障第35页/共72页 Functions： Lubricate, protect gastric mucosa

20、, gastric mucosal barrier; recovering gastric mucosal epithelia. (润滑、保护胃粘膜胃粘液屏障，胃粘膜屏障; ;胃粘膜上皮的更新)第36页/共72页The secretion of hydrochloric acid - parietal cell ( 盐酸壁细胞分泌盐酸壁细胞分泌) The functions of hydrochloric acid (盐盐 酸酸 作作 用用):): 第37页/共72页 1)Activate pepsinogen and supply suitable PH to pepsin (激活胃蛋白酶原

21、并给胃蛋白酶提供 活动所需的酸性pH) 2) Kill bacteria (杀菌) 3)Accelerate denaturation of protein, and facilitated to digestion (使蛋白质变性易于消化)第38页/共72页4)Accelerate the secretion of pancreatic juice、 bile、small intestinal juice. (促进胰液、胆汁、小肠液分泌)5)Accelerate the absorption of small intestinal to iron and calcium. (促进小肠对铁、钙

22、的吸收)第39页/共72页Function：1)Protect B12 doesnt hydrolyzed by digestive enzyme (保护B12不被消化酶水解)2)Accelerate the absorption of ileum mucosa to B12. (促进B12经回肠粘膜吸收)Intrinsic factor (内因子内因子) 第40页/共72页(2)The regulation of gastric juice secretion (胃液分泌的调节胃液分泌的调节) Sham feeding (假饲) Fig 5-18第41页/共72页Gastric juice

23、secretion of cephalic phase(头期胃液分泌) The food stimulates cephalic receptor cause gastric juice secretion. (食物刺激头部感受器引起的胃液分泌)第42页/共72页 Cephalic R nerve center gastric gland secrete gastric juice G cell - gastrin（胃泌素） characters : quantity and acidity is high, digestive enzyme is higher. (量、酸度很高，消化力(酶)

24、尤高 ) (头部R)(中 枢)(胃腺分泌胃液)第43页/共72页Gastric juice secretion of gastric phase (胃期胃液分泌) Food stimulates stomach cause the gastric juice secretion.(食物刺激胃引起的胃液分泌） 第44页/共72页 胃底胃体机械刺激胃底胃体机械刺激 中枢中枢胃腺胃腺 分泌胃液分泌胃液食物食物 胃幽门部机械刺激胃幽门部机械刺激 壁内神经丛壁内神经丛 胃幽门部化学刺激胃幽门部化学刺激幽门部幽门部G G细胞细胞 胃泌素胃泌素 Characters: Acidity is quite hi

25、gh, digestive enzyme is weaker than cephalic phase. (酸度高，消化力酸度高，消化力(酶酶)比头期的弱比头期的弱)第45页/共72页Gastric juice secretion of intestinal phase (肠期胃液分泌) The food stimulates intestine cause the gastric secretion （食物刺激肠引起的胃液分泌）第46页/共72页 S m a l l intestine (小肠小肠) Gastrin，entero-oxyntin（胃泌素、肠泌酸素 )Gastric gland

26、secrete gastric juice(胃腺分泌胃液)characters: few quantity. (量少)第47页/共72页Inhibitory regulation of gastric secretion (胃液分泌的抑制性调节胃液分泌的抑制性调节) ) 1)HCl 胃窦粘膜胃窦粘膜G G细胞细胞 mucosal D cell somatostain intestinal mucosa S cell secretin duodenal ampulla bulbomycin (粘膜D细胞)(生长抑素)(肠粘膜S细胞)(促胰液素)(12指肠球部)(球抑胃素)第48页/共72页2)2

27、) Fat small intestine enterogasterone mucosa (肠抑胃素肠抑胃素) ( (小肠粘膜小肠粘膜) ) gastric juice (胃液胃液) ) gastric movement (胃运动胃运动) ) 第49页/共72页3)Hypertonic solution small intestine mucosa (高张溶液高张溶液) () (小肠粘膜小肠粘膜) ) osmotic pressure R R inhibitive H H ( (小肠渗透压小肠渗透压R) (R) (抑制性抑制性H)H)第50页/共72页 4)PGE 4)PGE Vagus ne

28、rve, gastrin ( (迷走迷走N N、胃泌素、胃泌素) ) gastric wall release PGE (胃壁释放胃壁释放PGE) 第51页/共72页5)The effects of different food on gastric juice secretion (不同食物对胃液分泌的作用不同食物对胃液分泌的作用) Protein sugarfat (蛋白质糖类脂肪)Corn, sweet potato, alcohol, coffee (玉米面,白薯,红薯,酒精,咖啡)第52页/共72页3.The secretion of pancreatic juice (胰液的分泌胰

29、液的分泌) HCO3-H2OEnzymesSmall vessel cell(小导管细胞)Acinar cell(腺泡细胞)Pancreas (胰腺)第53页/共72页(1)The characters、components and functions of pancreatic juice (胰液的性质成分和作用胰液的性质成分和作用) CharactersAchromia and tasteless ( (无色无臭无色无臭) )第54页/共72页Components and functions Water dilute food (稀释食物稀释食物) )第55页/共72页 Sodium bi

30、carbonate (碳酸氢盐碳酸氢盐) ) counteract acid and supply suitable pH for activity of digestive enzyme in small intestine (中和胃酸并提供小肠内消化酶活动所需的最适pH)HCO3-第56页/共72页Organic components : digestive enzymes (有机成分主要是各种消化酶有机成分主要是各种消化酶) )： Pancreatic amylase (胰淀粉酶胰淀粉酶) malt sugar, glucose (麦芽糖、葡萄糖麦芽糖、葡萄糖)第57页/共72页 Lip

31、ase (胰脂肪酶胰脂肪酶 ) Fatty acid, glyceride, glycerin ( (脂肪酸、甘油一酯、甘油脂肪酸、甘油一酯、甘油) )第58页/共72页 胰蛋白酶胰蛋白酶 (trypsin) 糜蛋白酶糜蛋白酶 (chymotrypsin) ( (多肽、多肽、AA)AA) Trypsinogen(胰蛋白酶原)Chymotrypsinogen (糜蛋白酶原)第59页/共72页 Others Carboxypeptidase 羧基肽酶羧基肽酶 Deoxyribonuclease (脱氧脱氧)核糖核酸酶核糖核酸酶 第60页/共72页(2)The regulation of pancr

32、eatic juice (胰液分泌的胰液分泌的调节调节) ) Nr Enzyme is quite abundant, H2O and HCO3-are few. (酶很丰富，但酶很丰富，但H2O、HCO3-很少很少)HrHr Secretin (促胰液素促胰液素) Enzyme is quite few, H2O and HCO3- are abundant. (H2O (H2O、HCO3HCO3- -很丰富，但酶很少很丰富，但酶很少 ) )第61页/共72页 Cholecystokinin (胆囊收缩素 ) Enzyme is abundant, quantity is slightly

33、increased. (酶多，量增加少许) Gastrin (胃泌素) Enzyme is abundant, quantity is slightly increased. (酶多，量增加少许)第62页/共72页 Secretin (促胰液素促胰液素) )Food ( (刺激强度：盐酸刺激强度：盐酸 蛋白分解产物蛋白分解产物 脂酸钠脂酸钠) ) small intestine secretin( (促胰液素促胰液素) ) mucosa S cell ( (小肠粘膜小肠粘膜S S细胞细胞) ) 胰腺小导管细胞 第63页/共72页 Cholecystokinin, CCK (胆囊收缩素胆囊收缩素)Food ( (蛋白分解产物蛋白分解产物 脂酸钠脂酸钠 盐酸盐酸 脂肪脂肪) )small intestine CCK CCK mucosa I cell( (小肠粘膜小肠粘膜I I细胞细胞) ) cholecyst contraction pancreatic acinar cell (胆囊收缩) (胰腺腺泡细胞)第64页/共72页4.The Secretion and Regulation of Other Digestive Juice(其它消化液的分泌及调节)Bile (胆汁): Vagus N (迷走N) G., S., CCK (+)