Chapter 32 Gastrointestinal Secretions
1 Chapter 32 Gastrointestinal Secretions
Exocrine of the Gi tract Composition Ingest 2 1/d Function Saliva 1.5ld water pH68-70 A. Digest food B. Dilute the food into iso- Gastric secretion 2 osmotic fluid ld,pH1.5-3 C. Provide a favorable pH for Bile 0.5 l/d ph ll 78-8.0 the digestive enzymes intestine Pancreatic Juice ab D. Provide mucus for 1.5 ml/d ph8.0-84 8.5ld Intestinal secretion 1.5 lubrication and protection ldpH78-8.0 Cole of all parts of the absorbs 0.4 alimentary tract 1 Id 0.1 l/d water Regulation ex excreted
2 Exocrine of the GI tract Composition Function A. Digest food B. Dilute the food into isoosmotic fluid C. Provide a favorable pH for the digestive enzymes D. Provide mucus for lubrication and protection of all parts of the alimentary tract Regulation Saliva 1.5 l/d pH 6.8-7.0 Ingest 2 l/d water Gastric secretion 2 l/d, pH 1.5-3 Bile 0.5 l/d pH 7.8-8.0 Pancreatic juice 1.5 ml/d pH 8.0-8.4 Intestinal secretion 1.5 l/d pH 7.8-8.0 Small intestine absorbs 8.5 l/d Colon absorbs 0.4- 1 l/d 0.1 l/d water excreted
I. Salivarysecretien
3 I. Salivary secretion
Salivary gland s Parotid gland Accessory parotid gland Parotid duct Sublingual gland Submandibular duct Submandibular gland
4 Salivary gland
Secretion Saliva: water, ions, mucus, enzmes Acinar Cells:腺 HCO Primary secretion is 泡细胞 plasmet like(isotonic) Acinus Acinar cells ∠ Kt Duct Ducts are relatively impermeable to wate Secretory duct cells H 5
5 Secretion Saliva: water, ions, mucus, enzymes Acinar Cells: 腺 泡细胞