Adapted from "Nelson 11" Text, pg. 229.
| Table 1: Physical and Chemical Digestion | |
| Organ | Function |
| mouth | chewing of food and digestion of starch by salivary amylase |
| esophagus | transport of food from mouth to stomach |
| stomach | storage of food and initial digestion of proteins; production of the hormone gastrin (response to protein) that stimulates stomach's gastric glands to release gastric juice (pepsin and HCl) |
| small intestine | digestion of carbohydrates, proteins, lipids; most absorption of nutrients; production of the hormone secretin (response to HCl) that stimulates pancrease to release bicarbonate; production of the hormone CCK (response to fat) that stimulates gall bladder to release bile |
| pancreas | production of digestive enzymes that act on foods in small intestine; production of the hormone insulin which regulates blood sugar; storage of bicarbonate ions that neutralize stomach acid in small intestine |
| large intestine | absorption of water; production of some vitamins; storage of undigested food |
| Table 2: Substances Involved in Digestion | |
| Organ | Secretion and Function |
| mouth, salivary glands | salivary amylase - initiates breakdown of polysaccharides (eg. starch) to simple carbohydrates and dissacharides (eg. maltose) |
| esophagus | mucus - helps movement of food |
| stomach |
hydchloric acid - converts pepsinogen to pepsin; kills microbes
pepsinogen - when converted to pepsin, initiates digestion of proteins
mucus - protects stomach from pepsin and HCl rennin - coagulates proteins in milk |
| pancreas; small intestine |
bicarbonate - neutralizes HCl from stomach
trypsinogen - when converted to trypsin, converts long-chain peptides (many amino acids) into short-chain peptides
lipase - breaks down fats to glycerol and fatty acids
erepsin - completes the breakdown of proteins to amino acids disaccharidases (eg. maltase) - breaks down disaccharides (eg. maltose) into monosaccharides (eg. glucose) |
| liver | bile - emulsifies fat |
| gall bladder | bile - stores concentrated bile from liver |
| large intestine | mucus - helps movement of food |