1. Human digestion

2. Human digestive system (General plan) Accessory digestive organs

3. Organ/s Mechanical digestion Carbohydrate digestion Protein digestion Nucleic Acid digestion Lipid digestion Oral cavity Esophagus Pharynx Chewing Peristalsis StomachChurning Mixing Peristalsis Small intestine Lumen Peristalsis Mixing Small intestine Epithelium Polysaccharides (starch, glycogen) Polysaccharides (starch, glycogen) Disaccharides (sucrose, lactose) Disaccharides (sucrose, lactose) Salivary amylase Smaller polysaccharides, maltose Smaller polysaccharides, maltose Polysaccharides Pancreatic amylase Maltose and other disaccharides Disaccharidases Monosaccharides Proteins Pepsin Small polypeptides Pancreatic trypsin and chymotrypsin Smaller polypeptides Small peptides Dipeptidases, carboxypeptidase, aminopeptidase Amino acids DNA, RNA Pancreatic nucleases Nucleotides Nucleotidases Nucleosides Nucleosidases, phosphatases Nitrogenous bases, sugars, phosphates Nitrogenous bases, sugars, phosphates Fat globules Bile salts Fat droplets Pancreatic lipase Glycerol, fatty acids, glycerides Glycerol, fatty acids, glycerides Sites of digestion

6. Salivary glands – Water – Some enzymes Salivary amylase Lysozyme – Mucus or mucin Teeth Digestion in the Mouth

7. Swallowing: from mouth to stomach

8.  Muscular sac ◦ Churns & mixes food  Gastric glands ◦ Parietal cells  HCl, intrinsic factor ◦ Goblet cells  mucus ◦ Chief cells  pepsinogen, weak gastric lipase ◦ Gastrin  Hormone  Controls gastric juices  Comes out as chyme (2-6 hours) Digestion in the Stomach

9. Liver  Secretes bile (stored in gall bladder) (stored in gall bladder)  Emulsifies fats Gallbladder  Stores, concentrates, and releases bile into duodenum  Stimulated by the hormone cholecystokinin (CCK)

10. Exocrine function Acinar cells secrete pancreatic juice – Amylase – Lipase – Trypsin – Chymotrypsin – Carboxypeptidase – Nuclease – NaHCO 3 Secretin and cholecystokinin (CCK) fr intestinal wall stimulates PJ production Pancreas

12. Absorption in the small intestine

13. Reabsorption and elimination in the large intestine Areas of the colon Areas of the colon cecum cecum rectum rectum anus anus Absorption of water and electrolytes Absorption of water and electrolytes Concentration & elimination of solids Concentration & elimination of solids Home for bacteria Home for bacteria folic acid folic acid vitamin K vitamin K several B-vitamins several B-vitamins gases gases