蘿卜家園Chapter5DigestionandAbsorption消化與吸收.ppt

Chapter 5 Digestion and Absorption (消化與吸收),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 (食物在消化道內(nèi)被分解為小分子物質(zhì)的過程) Mechanical digestion (機(jī)械性消化) Chemical digestion (化學(xué)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. (食物經(jīng)消化后通過消化道粘膜進(jìn)入血液或淋巴的過程),Section1 Structure of Digestive Tract (消化管的結(jié)構(gòu)),Intracellular digestion (胞內(nèi)消化) Extracellular digestion (胞外消化),1.Human Digestive Tract (人的消化管),粘膜層： 上皮 上皮下層 粘膜肌層 粘膜下層 : C.T 組織結(jié)構(gòu) (Submucous layer) 環(huán)行肌 胃部是三層 Smooth muscle 內(nèi)斜,中環(huán),外縱 縱行肌 漿膜 : C.T (Serous membrane),(Tissue structure),(Mucous layer),2.The Innervation of Digestive Tract (消化管的神經(jīng)支配) Extrinsic NS & Intrinsic NS,CNS,肌間N叢,粘膜下N叢,R,平滑肌 分泌細(xì)胞 內(nèi)分泌細(xì)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在腹神經(jīng)節(jié)和腸系膜上下N節(jié)換元),交感N sympathetic nerve,NE,胃腸平滑肌 血管平滑肌 消化腺,運(yùn)動及分泌,內(nèi)在N元,副：延髓背核 疑核,迷走N,盆N,S,2-4,運(yùn)動及分泌,內(nèi)在N元 胃腸平滑肌 血管平滑肌 消化腺,Myenteric plexus (肌間N叢) Submucous plexus (粘膜下N叢),Intrinsic plexus (內(nèi)在N叢)：,包括感覺、中間、運(yùn)動神經(jīng)元構(gòu)成一個(gè)完整 且相對獨(dú)立的整合系統(tǒng),胃腸運(yùn)動及分泌,Section 2 The Movement and Regulation of Digestive Tract (消化管的運(yùn)動及調(diào)節(jié)),The movement of digestive tract (消化道的運(yùn)動): Mastication (咀嚼) Deglutition (吞咽) Gastrointestinal movement (胃腸運(yùn)動),Reflex (反射): Any response that occurs automatically without conscious effort. (在NS的參與下對刺激的規(guī)律性應(yīng)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 傳入N N中樞 傳出N 效應(yīng)器 ),1. Gastric movement (胃的運(yùn)動) (1)Receptive relaxation(胃的容受性舒張) 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、食管等處感受器經(jīng)迷走神經(jīng)反射性引起胃底、胃體肌舒張) significance,肽類纖維？,(2)Tonic contraction (緊張性收縮) (3)Peristalsis (蠕動),Gastric BER (胃的基本電節(jié)律): It stems from longitudinal muscle of greater curvature, 35 times per minutes, amplitude is about 515 mv. (起源于胃大彎的縱行肌層，每分鐘35次，振幅約515 mv ),Function of peristalsis (蠕動) ： Lead to ample mixing of chyme and digestive juice, this is facilitated for chemical digestion. 使食糜與消化液充分混合，利于化學(xué)性消化, Mill food (mechanical digestion) 磨碎食物 (即機(jī)械性消化) Push chyme 推進(jìn)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指腸的過程),(1)胃排空 (gastric emptying),Emptying velocity (排空速度)： Sugarproteinfat; Sparse, thin, isosmotic quick (稀、細(xì)、等滲 快) (反之則慢),(2) Regulation of gastric emptying (胃排空的調(diào)控),Entogastric factors accelerate emptying (胃內(nèi)因素促進(jìn)排空)： Entogastric food（Nr） (胃內(nèi)食物) Gastrin （Hr） (胃泌素),Factors of duodenum inhibit emptying (12脂腸因素抑制排空)： Gastrointestinal reflex（Nr）(腸胃反射) Enterogastrone （Hr） (腸抑胃素),Emptying process (排空過程)：,Entogastric food(胃內(nèi)食物) emptying stopped (排空停止) motility of the stomach (胃運(yùn)動) 胃運(yùn)動 幽門括約肌舒張 幽門括約肌收縮 胃內(nèi)壓12指腸內(nèi)壓,N (腸胃反射) H (腸抑胃素),Nr.Hr,排空,腸內(nèi)胃酸被中和 食物被消化吸收,3. The movements of small intestine (小腸的運(yùn)動),(1)Tonic contraction (緊張性收縮) Functions： Maintain basic pressure (維持基礎(chǔ)壓力) The basis of movements (是腸運(yùn)動的基礎(chǔ)) Fix and keep shape of small intestine (維持小腸的位置形狀),(2)Segmentation contraction (分節(jié)運(yùn)動),Functions： It can lead to ample mixing of chyme and digestive juice, this is facilitated for chemical digestion. (使食糜與消化液充分混合，利于化學(xué)性消化) It can accelerate close contact of chyme and intestinal wall ,this is facilitated for absorption. (使食糜與腸壁緊密接觸，利于吸收), It can press intestinal wall, accelerate blood and lymph circumfluence. (擠壓腸壁而促進(jìn)血液、淋巴回流) (3)Peristalsis (蠕動) Peristalsis function : push chyme (推進(jìn)食糜),(4)Large intestinal movement and defecation (大腸運(yùn)動和排便) The movement forms of large intestine (大腸運(yùn)動形式),1)袋狀往返運(yùn)動 2)分節(jié)或多袋推進(jìn)運(yùn)動 3) Peristalsis (蠕動) (mass peristalsis,集團(tuán)蠕動),Brain stem , cerebral cortex (腦干、大腦皮層) S2-S4 直腸牽張R,盆N,陰 部 N,腹肌膈肌,糞,糞,降結(jié)腸 乙狀結(jié)腸 直腸,收 縮,內(nèi)括約肌松馳,Defecation reflex (排便反射),外括約肌松馳,(5)Regulation of digestive tract (消化管運(yùn)動的調(diào)節(jié)),Electrical activity (電活動) BER AP Nerve factors (神經(jīng)因素) Sympathetic nerve (-) gastrointestinal movement 交感N (-) 胃腸運(yùn)動 Vagus nerve (+) gastrointestinal movement 迷走N (+) 胃腸運(yùn)動,Intraparietal nerve plexus (壁內(nèi)N叢) : Regulating gastrointestinal movement (調(diào)節(jié)胃腸運(yùn)動) Cerebral cortex(大腦皮層) : Interest for food effects digestion. Psychogenic enterorrhea (對食物的好惡對消化的影響 精神性腹瀉),3. Humoral factors (體液因素): Gastrointestinal hormone (主胃腸激素):,Motilin (胃動素) Gastrin (胃泌素),抑胃肽 NE Secretin (促胰液素),movement,movement,Section 3 The Secretion and Regulation of Digestive Juice (消化液的分泌及調(diào)節(jié)),1.The secretion of saliva (唾液的分泌),(1)The characters 、components and functions of saliva (唾液性質(zhì)與成分與作用) Moisten , dissolve food (濕潤、溶解食物) clean, protect mouth cavity (清潔、保護(hù)口腔) lubricate , hydrolyze amylum , kill bacteria (潤滑 水解淀粉 殺菌),(2) The regulation of salivary secretion (唾液分泌的調(diào)節(jié)) Double excitation effect of sympathesis nerve and parasympathesis nerve (交感與副交感雙重興奮作用) Conditioned reflex (條件反射) Unconditioned reflex (非條件反射),2. Gastric secretion (胃液的分泌),(1)Characters ,components and functions of gastric juice (胃液的性質(zhì)、成分和作用),無色透明，pH 0.91.5,Pepsinogen (胃蛋白酶原) chief cell secretion (主細(xì)胞分泌),pepsin 胃蛋白酶,HCl,protein 蛋白質(zhì),月,示,和胨,+,pH2,Mucus and HCO3- (粘液與碳酸氫鹽),胃粘液-碳酸氫鹽屏障,表面上皮細(xì)胞 粘液頸細(xì)胞 賁門腺 pyloric gland(幽門腺),glycoprotein 糖蛋白,Functions： Lubricate, protect gastric mucosa, gastric mucosal barrier; recovering gastric mucosal epithelia. (潤滑、保護(hù)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 ( 鹽酸壁細(xì)胞分泌),The functions of hydrochloric acid (鹽 酸 作 用):,1)Activate pepsinogen and supply suitable PH to pepsin (激活胃蛋白酶原并給胃蛋白酶提供 活動所需的酸性pH) 2) Kill bacteria (殺菌) 3)Accelerate denaturation of protein, and facilitated to digestion (使蛋白質(zhì)變性易于消化),4)Accelerate the secretion of pancreatic juice、 bile、small intestinal juice. (促進(jìn)胰液、膽汁、小腸液分泌) 5)Accelerate the absorption of small intestinal to iron and calcium. (促進(jìn)小腸對鐵、鈣的吸收),Function： 1)Protect B12 doesnt hydrolyzed by digestive enzyme (保護(hù)B12不被消化酶水解) 2)Accelerate the absorption of ileum mucosa to B12. (促進(jìn)B12經(jīng)回腸粘膜吸收),Intrinsic factor (內(nèi)因子),(2)The regulation of gastric juice secretion (胃液分泌的調(diào)節(jié)),Sham feeding (假飼) Fig 5-18,Gastric juice secretion of cephalic phase (頭期胃液分泌),The food stimulates cephalic receptor cause gastric juice secretion. (食物刺激頭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 ),(頭部R),(中 樞),(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）,胃底胃體機(jī)械刺激 中樞胃腺 分泌胃液 食物 胃幽門部機(jī)械刺激 壁內(nèi)神經(jīng)叢 胃幽門部化學(xué)刺激幽門部G細(xì)胞 胃泌素 Characters: Acidity is quite high, digestive enzyme is weaker than cephalic phase. (酸度高，消化力(酶)比頭期的弱),Gastric juice secretion of intestinal phase (腸期胃液分泌) The food stimulates intestine cause the gastric secretion （食物刺激腸引起的胃液分泌）,Small intestine (小腸),food,Gastrin，entero-oxyntin （胃泌素、腸泌酸素 ),Gastric gland secrete gastric juice (胃腺分泌胃液),characters: few quantity. (量少),Inhibitory regulation of gastric secretion (胃液分泌的抑制性調(diào)節(jié)),1) HCl 胃竇粘膜G細(xì)胞 mucosal D cell somatostain intestinal mucosa S cell secretin duodenal ampulla bulbomycin ,胃 泌 素,胃 液,(粘膜D細(xì)胞),(生長抑素),(腸粘膜S細(xì)胞),(促胰液素),(12指腸球部),(球抑胃素),2) Fat small intestine enterogasterone mucosa (腸抑胃素) (小腸粘膜) gastric juice (胃液) gastric movement (胃運(yùn)動),3)Hypertonic solution small intestine mucosa (高張溶液) (小腸粘膜) osmotic pressure R inhibitive H (小腸滲透壓R) (抑制性H),胃液,4)PGE Vagus nerve, gastrin (迷走N、胃泌素) gastric wall release PGE (胃壁釋放PGE),胃液,5)The effects of different food on gastric juice secretion (不同食物對胃液分泌的作用),Protein sugarfat (蛋白質(zhì)糖類脂肪) Corn, sweet potato, alcohol, coffee (玉米面,白薯,紅薯,酒精,咖啡),3.The secretion of pancreatic juice (胰液的分泌),HCO3- H2O,Enzymes,Small vessel cell (小導(dǎo)管細(xì)胞),Acinar cell (腺泡細(xì)胞),Pancreas (胰腺),(1)The characters、components and functions of pancreatic juice (胰液的性質(zhì)成分和作用) Characters,Achromia and tasteless (無色無臭),pH7.8-8.4,Components and functions,Water dilute food (稀釋食物),Sodium bicarbonate (碳酸氫鹽) counteract acid and supply suitable pH for activity of digestive enzyme in small intestine (中和胃酸并提供小腸內(nèi)消化酶活動所需的最適pH),pH7-8,H,HCO3-,+,Organic components : digestive enzymes (有機(jī)成分主要是各種消化酶)：, Pancreatic amylase (胰淀粉酶) malt sugar, glucose (麥芽糖、葡萄糖),淀粉, Lipase (胰脂肪酶 ) Fatty acid, glyceride, glycerin (脂肪酸、甘油一酯、甘油),輔脂酶,脂肪, 胰蛋白酶 (trypsin) 糜蛋白酶 (chymotrypsin) (多肽、AA),腸 致 活 酶,蛋白質(zhì),和胨,酸,Trypsinogen (胰蛋白酶原),Chymotrypsinogen (糜蛋白酶原),+,月示, Others Carboxypeptidase 羧基肽酶 Deoxyribonuclease (脫氧)核糖核酸酶,(2)The regulation of pancreatic juice (胰液分泌的調(diào)節(jié)),Nr Enzyme is quite abundant, H2O and HCO3are few. (酶很豐富，但H2O、HCO3-很少) Hr Secretin (促胰液素) Enzyme is quite few, H2O and HCO3 are abundant. (H2O、HCO3-很豐富，但酶很少 ), Cholecystokinin (膽囊收縮素 ) Enzyme is abundant, quantity is slightly increased. (酶多，量增加少許) Gastrin (胃泌素) Enzyme is abundant, quantity is slightly increased. (酶多，量增加少許),Secretin (促胰液素),Food (刺激強(qiáng)度：鹽酸蛋白分解產(chǎn)物脂酸鈉) small intestine secretin(促胰液素) mucosa S cell (小腸粘膜S細(xì)胞),水鹽,胰腺 小導(dǎo)管細(xì)胞,Cholecystokinin, CCK (膽囊收縮素),Food (蛋白分解產(chǎn)物脂酸鈉鹽酸脂肪) small intestine CCK mucosa I cell (小腸粘膜I細(xì)胞) cholecyst contraction pancreatic acinar cell,排膽汁,酶,(膽囊收縮),(胰腺腺泡細(xì)胞),4.The Secretion and Regulation of Other Digestive Juice(其它消化液的分泌及調(diào)節(jié)),Bile (膽汁): Vagus N