8 2. Digestion in the mouth esophagus ● Saliva& its function k Nature composition of saliva pH6.6~7.1,99% water Salivary amylase, lysozyme, salt, etc. *k Functions of saliva Moisten the cavity solve food; keep the mouth clean; anti-bacteria; digest starch k Regulation of salivary secretion Pure neuroregulation Conditioned unconditioned reflex
§ 2. Digestion in the mouth & esophagus • Saliva & its function * Nature & Composition of saliva pH 6.6~7.1, 99% water Salivary amylase, lysozyme, salt, etc. * Functions of saliva Moisten the cavity & solve food; keep the mouth clean; anti-bacteria; digest starch * Regulation of salivary secretion Pure neuroregulation Conditioned & unconditioned reflex
e Mastication or chewing its effects 米 Definition 米 Effects Break up large food particles; mixes the food with saliva; aid swallowing o Deglutition or swallowing *k Definition k Process Ist, 2nd 3rd phase Peristalsis lower esophageal sphincter
• Mastication or chewing & its effects * Definition * Effects Break up large food particles; mixes the food with saliva; aid swallowing • Deglutition or swallowing * Definition * Process 1st, 2nd & 3rd phase Peristalsis & lower esophageal sphincter
收缩波 舒张波 Peristalsis of the esophagus
Peristalsis of the esophagus
83. Digestion in the stomach e Gastric juice its secretion k Nature Compositions functions pH 0.9-1.5, colorless, 1.5-2.5 L/day Hydrochloric acid (HCl) Secreted by parietal cells Basic secretion: 0.5 mmol/h Max secretion: 20-25 mmol/h Mechanism of hcl secretion Functions: see next page
§ 3. Digestion in the stomach • Gastric juice & its secretion * Nature, Compositions & functions pH 0.9~1.5, colorless, 1.5~2.5 L/day Hydrochloric acid (HCl) Secreted by parietal cells Basic secretion: 0~5 mmol/h Max secretion: 20~25 mmol/h Mechanism of HCl secretion Functions: see next page
40 30 鎰长 20 10 0.5 1.0 1.5 壁细胞数(109细胞 Relationship between max volume of HCl secretion the number of parietal cells
Relationship between max volume of HCl secretion & the number of parietal cells