1、 Gastrointestinal tract 胃肠道胃肠道 Accessory organs 辅助器官 (Para. 1) The organization of the gastrointestinal tract What are the four layers? (Concentric layers) Sublayers Intrinsic nerves (内神经内神经 ) The gastrointestinal tract 胃肠道 The submucosal plexus (Meissner plexus) 黏膜下层神经丛 （ 即迈斯纳神经丛） The myenteric ple
2、xus (Auerbach plexus) 肠肌神经丛 （即奥尔巴赫神经丛 ) The subserosal plexus 浆膜下神经网丛 What are the three nerve plexuses? 唾液 saliva 味蕾 taste buds 嗅神经 olfactory nerves 胃液的分泌 the secretion of gastric juice 恒牙 permanent teeth 咀嚼 mastication 食管 esophagus 蠕动 peristalsis 外层纵向肌 outer longitudinal layers of muscles 内层环形肌 in
3、ner circular layers of muscles Mouth and Esophagus 口腔和食道 1.Three pairs of salivary glands 1 liter of saliva per day salivation 唾液分泌 1.Three pairs of salivary glands 1 liter of saliva per day 2. Autonomic nervous system (自主神经系统自主神经系统 )controls salivation. (sympathetic and parasympathetic) (But not re
4、gulated by hormones) salivation 唾液分泌 食糜 chyme 十二指肠 duodenum The stomachs major anatomic boundaries: 食管括约肌食管括约肌 贲门贲门 胃大弯和胃小胃大弯和胃小 弯弯 幽门括约肌幽门括约肌 十二指肠十二指肠 What are the functional areas of the stomach? fundus, body, antrum Stomach 胃 胃壁 stomach wall 斜肌层 a layer of oblique muscle 中环层 和 外纵层 在 胃底 最薄 The cir
5、cular and longitudinal layers of muscle are thinnest in the fundus. 胃体和 胃窦 逐渐变厚 The layers become progressively thicker in the body and antrum. 胃粘膜 the mucosa of the stomach Stomach 胃 1. 血液通过 腹腔一支动脉 输入胃中 Blood is supplied to the stomach by a branch of the celiac artery. 2. 主动脉沿 胃大弯 和 胃小弯 分布 Major ar
6、teries lie along the greater and lesser curvatures. 3. 分叉深入 浆膜 和 肌层 branch and penetrate the serosa and muscle layers 4. 形成丰富的 侧支循环 form a rich collateral circulation Stomach 胃 Cardiovascular System: Major Vessels 1. renal artery 肾动脉 2.vertebral artery 脊椎动脉 3. subclavian artery 锁骨下动脉 4. aorta 主动脉 5.
7、 coronary artery 冠状动脉 6. celiac artery 腹腔动脉 7. superior mesenteric artery 肠系膜上动脉 8. lumbar artery 腰动脉 9. inferior mesenteric artery 肠系膜下动脉 10. gonadal artery 生殖腺动脉 renal artery 肾动脉 vertebral artery 脊椎动脉 3. subclavian artery 锁骨下动 脉 4. aorta 主动脉 5. coronary artery 冠状动脉 6. celiac artery 腹腔动脉 7. superio
8、r mesenteric artery 肠系膜上动 8. lumbar artery 腰动脉 9. inferior mesenteric artery 肠系膜下动 10. gonadal artery 生殖腺动脉 A rich circulationstomach liver Gastric Vein Splenic Vein 静止状态下没有 壁张力 In resting state, no wall tension. 吞咽动作致使 底部 松弛 Swallowing causes the fundus to relax. 食物存储在 垂直层或斜纤层 Food is stored in ver
9、tical or oblique layers 液体相对快速地流入 胃窦 Fluids flow relatively quickly down to the antrum. 蠕动波 使胃动力开始增强 Gastric motility increases with peristaltic waves (蠕动收缩频率 )同时受 神经和激素活动 影响。 Influenced by neural and hormonal activity. Gastric Motility 胃运动 1. 胃液 或 胃分泌物 gastric juices or gastric secretion 2. 粘液 、 酸
10、、 酶 、 激素 和 内因子 Mucus, acid, enzymes, hormones, and intrinsic factor 3.激素 被分泌到血液里 The hormones are secreted into the blood. 4. 其他胃分泌物直接进入 胃腔 。 The other gastric secretions into the stomach lumen Gastric Secretion 胃分泌 粘液粘液 形成一道防护屏障来抵御形成一道防护屏障来抵御 酸酸 和和 蛋白水解酶蛋白水解酶 。 Mucus forms a protective barrier agai
11、nst acid and proteolytic enzymes. Gastric Secretion 胃分泌 1. 胃液的成分取决于其胃液的成分取决于其 体积体积 和和 流动速度流动速度 The composition of gastric juice depends on volume and flow rate 2. 氢和氯 , 钠 , 钾 的浓度变化 The change of the concentrations of hydrogen and chloride, sodium , and potassium 3. 分泌的速度和体积在早上为最小值，在分泌的速度和体积在早上为最小值，在
12、 下午和晚上达到最大值。下午和晚上达到最大值。 The rate and volume of secretion are lowest in the morning and evening. Gastric Secretion 胃分泌 What inhibits gastric secretion(胃分泌胃分泌 )? (L.95-96) Unpleasant odors and tastes; Rage, fear, pain What causes increased secretions? 分泌物增多与敌对心理或敌意厌恶分泌物增多与敌对心理或敌意厌恶 感有关感有关 . Gastric Se
13、cretion 胃分泌 1. 功能上可分为三部分：十二指肠功能上可分为三部分：十二指肠 ，空肠和回肠，空肠和回肠 Divided into 3 segments: the duodenum, jejunum, and ileum 2. 腹膜 是包裹在腹部器官和 骨盆腔 上的一层 浆膜浆膜 The peritoneum is the serous membrane surrounding the organs of abdomen and pelvic cavity. Small Intestine 小肠 Small intestine Ileocecal valve jejunum A sus
14、pensory ligament duodenum jejunum A suspensory ligament 腹膜 Peritoneum Peritoneum Mesentery 1. 十二指肠的动脉供应主要由 胃十 二指肠动脉 提供 。 The arterial supply to the duodenum arises primarily from the gastroduodenal artery. 2. 小肠平滑肌 分布为两层：外部的 纵层和内部较厚的环层。 The smooth muscles of the small intestine are arranged in two l
15、ayers. Small Intestine 小肠 Arterial supply to small intestine Gastroduodenal artery 食物 氯化氢和胃蛋白酶 的作用 (分解食物纤维和蛋白 ) 食糜 胰腺酶，肠 道酶和胆盐的作用 碳水 化合物 /蛋白质 /脂肪分解 水 /维生素 /电解液通过传输， 扩散或易化扩散 经肠 道黏膜 吸收。 Intestinal Digestion and Asborption 肠道消化与吸收 小肠运动小肠运动 食糜食糜 刺激肠道运动刺激肠道运动 混合有来自混合有来自 肝脏肝脏 ， 胰腺胰腺 和和 肠腺肠腺 的分泌物的分泌物 搅拌运动搅
16、拌运动 腔内物腔内物 接触到接触到 绒毛吸收细胞绒毛吸收细胞 推进推进 使食糜进入大肠使食糜进入大肠 Chyme stimulates intestinal movements Mix in secretion from the liver, pancreas, and intestinal glands a churning motion brings the luminal content into contact with the absorbing cells of the villi. Advance the chyme toward the large intestine. Int
17、estinal Motility 肠道运动 肠道运动受两种运动影响：结 肠袋分节运动和蠕动。 Intestinal motility is affected by two movements: Haustral segmentation peristalsis Intestinal Motility 肠道运动 The large intestine consists of: cecum 盲肠盲肠 a pouch appendix 阑尾阑尾 vermiform colon 结肠结肠 rectum 直肠直肠 anal canal 肛管肛管 Large Intestine 大肠 The four p
18、arts of the colon ascending colon 升结肠升结肠 transverse colon 横结肠横结肠 descending colon 降结肠降结肠 sigmoid colon 乙状结肠乙状结肠 Large Intestine 大肠 1. 肠内物通过盲肠和结肠受肠内物通过盲肠和结肠受 两个括约两个括约 肌肌 控制：控制： the ileocecal valve回盲瓣回盲瓣 控制食糜从回肠进入盲肠控制食糜从回肠进入盲肠 the OBeirne sphincter奥贝恩括约肌奥贝恩括约肌 控制废物从乙状结肠进入直肠。控制废物从乙状结肠进入直肠。 2. anal sphi
19、ncters 肛门括约肌肛门括约肌 internal anal sphincter肛门括约肌肛门括约肌 external anal sphincter肛门括约肌肛门括约肌 Large Intestine 大肠 What causes to kill pathogens ( 病原病原 体体 ) and bacteria throughout the gastrointestinal tract? Acid in the stomach Bile acid secretion Intestinal motility Antibody production Where are anaerobes m
20、ainly found? (L.196-197) Intestinal Bacteria 肠道细菌 Accessory Organ of Digestion 消化的辅助 器官 What are the accessory organs of digestion? Liver produces bile gallbladder stores bile exocrine pancreas produces enzymes needed for the complete digestion of carbohydrates, proteins, and fats. Besides, produces
21、 an alkaline fluid. Liver It also receives nutrients absorbed by the small intestine, metabolizing and synthesizing Accessory Organ of Digestion 消化的辅助 器官 Liver-Secretion of Bile 1. Where is the liver located? 2. L.216 3. 2. The metabolic function of the liver require a large amount of blood hepatic
22、artery( 肝动脉肝动脉 )provides oxygenated blood portal venous blood (门静脉血门静脉血 ) constitutes70% of the blood supply to the liver. Accessory Organ of Digestion 消化的辅助 器官 Liver-Secretion of Bile Secreting 700 to 1200ml bile per day What does the bile contain? bile salts cholestrol bilirubin, electrolytes wate
23、r 胆盐、胆固醇、胆红素、电解液和水胆盐、胆固醇、胆红素、电解液和水 What is the function of bile salts? (L. 233-235) Accessory Organ of Digestion 消化的辅助 器官 Gallbladder (胆囊胆囊 ) 1. Position and Function 2. How does the bile move? 3. 4. 胆汁从肝脏流出，经由左或右肝胆汁从肝脏流出，经由左或右肝 导管进入肝总管，并在此遇到奥迪导管进入肝总管，并在此遇到奥迪 括约肌的阻力。奥迪括约肌掌控胆括约肌的阻力。奥迪括约肌掌控胆 汁流入十二指肠。此
24、后，胆汁经由汁流入十二指肠。此后，胆汁经由 胆管进入胆囊，并在此贮存、变浓胆管进入胆囊，并在此贮存、变浓 。 Accessory Organ of Digestion 消化的辅助 器官 Gallbladder (胆囊胆囊 ) 3. How does Gallbladder work? 饭后饭后 30分钟内，胆囊开始收缩，奥分钟内，胆囊开始收缩，奥 迪括约肌松弛，迫使胆汁通过大的迪括约肌松弛，迫使胆汁通过大的 十二指肠乳突进入十二指肠。在口十二指肠乳突进入十二指肠。在口 腔和胃消化阶段，迷走神经的类胆腔和胃消化阶段，迷走神经的类胆 碱分支控制胆囊的收缩。胆囊收缩碱分支控制胆囊的收缩。胆囊收缩 的
25、荷尔蒙调节源于缩胆囊素和胃动的荷尔蒙调节源于缩胆囊素和胃动 素的释放，缩胆囊素和胃动素是在素的释放，缩胆囊素和胃动素是在 脂肪环境下十二指肠黏膜分泌的。脂肪环境下十二指肠黏膜分泌的。 Accessory Organ of Digestion 消化的辅助 器官 Exocrine Pancreas (外分泌胰腺外分泌胰腺 ) 1. Location of Pancreas 2. Why is the pancreas unique? It has both endocrine and exocrine functions. 1. 3. What does the endocrine pancrea
26、s(内分泌胰腺内分泌胰腺 ) do? 2. secretes hormones: 3. insulin (胰岛素胰岛素 ) 4. glucagons (高血糖素高血糖素 ) Accessory Organ of Digestion 消化的辅助 器官 4. What does the exocrine pancreas ( 外外 分泌胰腺分泌胰腺 ) do? secrete enzymes(酶酶 ) and alkaline fluids (碱性流体碱性流体 ) Accessory Organ of Digestion 消化的辅助 器官 Secretions drain into a syste
27、m of ducts that leads to the pancreatic duct, which empties into the common bile duct at the ampulla of Vate. 分泌物分泌物 流入导管系统，导管系统通流入导管系统，导管系统通 向向 胰导管胰导管 ，然后进入，然后进入 法特壶腹法特壶腹 处的处的 总胆管总胆管 。 Accessory Organ of Digestion 消化的辅助 器官 In some individuals an accessory duct branches off the pancreatic duct and drains directly into the duodenum at an opening called the minor duodenal papilla. 在某些个体中可见在某些个体中可见 辅助性导管辅助性导管 分支于分支于 胰导胰导 管管 ，胆汁在被称为，胆汁在被称为 小的十二指肠乳突小的十二指肠乳突 的开的开 口处直接进入口处直接进入 十二指肠十二指肠 。
