萝卜家园Chapter5DigestionandAbsorption消化与吸收.ppt

Chapter 5 Digestion and Absorption (消化与吸收),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) Chemical digestion (化学性消化),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),Section1 Structure of Digestive Tract (消化管的结构),Intracellular digestion (胞内消化) Extracellular digestion (胞外消化),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 : C.T 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),2.The Innervation of Digestive Tract (消化管的神经支配) Extrinsic NS & Intrinsic NS,CNS,肌间N丛,粘膜下N丛,R,平滑肌 分泌细胞 内分泌细胞 血管,交.副交N,交.副交N,局部,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),交感N sympathetic nerve,NE,胃肠平滑肌 血管平滑肌 消化腺,运动及分泌,内在N元,副：延髓背核 疑核,迷走N,盆N,S,2-4,运动及分泌,内在N元 胃肠平滑肌 血管平滑肌 消化腺,Myenteric plexus (肌间N丛) Submucous plexus (粘膜下N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,胃肠运动及分泌,Section 2 The Movement and Regulation of Digestive Tract (消化管的运动及调节),The movement of digestive tract (消化道的运动): Mastication (咀嚼) Deglutition (吞咽) Gastrointestinal movement (胃肠运动),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 效应器 ),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,肽类纤维？,(2)Tonic contraction (紧张性收缩) (3)Peristalsis (蠕动),Gastric BER (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 ),Function of peristalsis (蠕动) ： 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, Mill food (mechanical digestion) 磨碎食物 (即机械性消化) Push chyme 推进食糜,2.Gastric Emptying and Its Regulation (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)胃排空 (gastric emptying),Emptying velocity (排空速度)： Sugarproteinfat; Sparse, thin, isosmotic quick (稀、细、等渗 快) (反之则慢),(2) Regulation of gastric emptying (胃排空的调控),Entogastric factors accelerate emptying (胃内因素促进排空)： Entogastric food（Nr） (胃内食物) Gastrin （Hr） (胃泌素),Factors of duodenum inhibit emptying (12脂肠因素抑制排空)： Gastrointestinal reflex（Nr）(肠胃反射) Enterogastrone （Hr） (肠抑胃素),Emptying process (排空过程)：,Entogastric food(胃内食物) emptying stopped (排空停止) motility of the stomach (胃运动) 胃运动 幽门括约肌舒张 幽门括约肌收缩 胃内压12指肠内压,N (肠胃反射) H (肠抑胃素),Nr.Hr,排空,肠内胃酸被中和 食物被消化吸收,3. The movements of small intestine (小肠的运动),(1)Tonic contraction (紧张性收缩) Functions： Maintain basic pressure (维持基础压力) The basis of movements (是肠运动的基础) Fix and keep shape of small intestine (维持小肠的位置形状),(2)Segmentation contraction (分节运动),Functions： It can 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), It can press intestinal wall, accelerate blood and lymph circumfluence. (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),(4)Large intestinal movement and defecation (大肠运动和排便) The movement forms of large intestine (大肠运动形式),1)袋状往返运动 2)分节或多袋推进运动 3) Peristalsis (蠕动) (mass peristalsis,集团蠕动),Brain stem , cerebral cortex (脑干、大脑皮层) S2-S4 直肠牵张R,盆N,阴 部 N,腹肌膈肌,粪,粪,降结肠 乙状结肠 直肠,收 缩,内括约肌松驰,Defecation reflex (排便反射),外括约肌松驰,(5)Regulation of digestive tract (消化管运动的调节),Electrical activity (电活动) BER AP Nerve factors (神经因素) Sympathetic nerve (-) gastrointestinal movement 交感N (-) 胃肠运动 Vagus nerve (+) gastrointestinal movement 迷走N (+) 胃肠运动,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),3. Humoral factors (体液因素): Gastrointestinal hormone (主胃肠激素):,Motilin (胃动素) Gastrin (胃泌素),抑胃肽 NE Secretin (促胰液素),movement,movement,Section 3 The Secretion and Regulation of Digestive Juice (消化液的分泌及调节),1.The secretion of saliva (唾液的分泌),(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 cavity (清洁、保护口腔) lubricate , hydrolyze amylum , kill bacteria (润滑 水解淀粉 杀菌),(2) The regulation of salivary secretion (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),2. Gastric secretion (胃液的分泌),(1)Characters ,components and functions of gastric juice (胃液的性质、成分和作用),无色透明，pH 0.91.5,Pepsinogen (胃蛋白酶原) chief cell secretion (主细胞分泌),pepsin 胃蛋白酶,HCl,protein 蛋白质,月,示,和胨,+,pH2,Mucus and HCO3- (粘液与碳酸氢盐),胃粘液-碳酸氢盐屏障,表面上皮细胞 粘液颈细胞 贲门腺 pyloric gland(幽门腺),glycoprotein 糖蛋白,Functions： Lubricate, protect gastric mucosa, 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),The secretion of hydrochloric acid - parietal cell ( 盐酸壁细胞分泌),The functions of hydrochloric acid (盐 酸 作 用):,1)Activate pepsinogen and supply suitable PH to pepsin (激活胃蛋白酶原并给胃蛋白酶提供 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),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、钙的吸收),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),(2)The regulation of gastric juice secretion (胃液分泌的调节),Sham feeding (假饲) Fig 5-18,Gastric juice 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),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)尤高 ),(头部R),(中 枢),(胃腺分泌胃液),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）,胃底胃体机械刺激 中枢胃腺 分泌胃液 食物 胃幽门部机械刺激 壁内神经丛 胃幽门部化学刺激幽门部G细胞 胃泌素 Characters: Acidity is quite high, digestive enzyme is weaker than cephalic phase. (酸度高，消化力(酶)比头期的弱),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）,Small intestine (小肠),food,Gastrin，entero-oxyntin （胃泌素、肠泌酸素 ),Gastric gland secrete gastric juice (胃腺分泌胃液),characters: few quantity. (量少),Inhibitory regulation of gastric secretion (胃液分泌的抑制性调节),1) HCl 胃窦粘膜G细胞 mucosal D cell somatostain intestinal mucosa S cell secretin duodenal ampulla bulbomycin ,胃 泌 素,胃 液,(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),2) Fat small intestine enterogasterone mucosa (肠抑胃素) (小肠粘膜) gastric juice (胃液) gastric movement (胃运动),3)Hypertonic solution small intestine mucosa (高张溶液) (小肠粘膜) osmotic pressure R inhibitive H (小肠渗透压R) (抑制性H),胃液,4)PGE Vagus nerve, gastrin (迷走N、胃泌素) gastric wall release PGE (胃壁释放PGE),胃液,5)The effects of different food on gastric juice secretion (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),3.The secretion of pancreatic juice (胰液的分泌),HCO3- H2O,Enzymes,Small vessel cell (小导管细胞),Acinar cell (腺泡细胞),Pancreas (胰腺),(1)The characters、components and functions of pancreatic juice (胰液的性质成分和作用) Characters,Achromia and tasteless (无色无臭),pH7.8-8.4,Components and functions,Water dilute food (稀释食物),Sodium bicarbonate (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),pH7-8,H,HCO3-,+,Organic components : digestive enzymes (有机成分主要是各种消化酶)：, Pancreatic amylase (胰淀粉酶) malt sugar, glucose (麦芽糖、葡萄糖),淀粉, Lipase (胰脂肪酶 ) Fatty acid, glyceride, glycerin (脂肪酸、甘油一酯、甘油),辅脂酶,脂肪, 胰蛋白酶 (trypsin) 糜蛋白酶 (chymotrypsin) (多肽、AA),肠 致 活 酶,蛋白质,和胨,酸,Trypsinogen (胰蛋白酶原),Chymotrypsinogen (糜蛋白酶原),+,月示, Others Carboxypeptidase 羧基肽酶 Deoxyribonuclease (脱氧)核糖核酸酶,(2)The regulation of pancreatic juice (胰液分泌的调节),Nr Enzyme is quite abundant, H2O and HCO3are few. (酶很丰富，但H2O、HCO3-很少) Hr Secretin (促胰液素) Enzyme is quite few, H2O and HCO3 are abundant. (H2O、HCO3-很丰富，但酶很少 ), Cholecystokinin (胆囊收缩素 ) Enzyme is abundant, quantity is slightly 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),Secretin (促胰液素),Food (刺激强度：盐酸蛋白分解产物脂酸钠) small intestine secretin(促胰液素) mucosa S cell (小肠粘膜S细胞),水盐,胰腺 小导管细胞,Cholecystokinin, CCK (胆囊收缩素),Food (蛋白分解产物脂酸钠盐酸脂肪) small intestine CCK mucosa I cell (小肠粘膜I细胞) cholecyst contraction pancreatic acinar cell,排胆汁,酶,(胆囊收缩),(胰腺腺泡细胞),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