Fig 41 1 Fig 41 2 Essential amino

Fig. 41 -1

Fig. 41 -2 Essential amino acids for adults Methionine Valine Threonine Phenylalanine Leucine Corn (maize) and other grains Isoleucine Tryptophan Lysine Beans and other legumes

Fig. 41 -3

Table 41 -1

Table 41 -1 a

Table 41 -1 b

Table 41 -2

Table 41 -2 a

Table 41 -2 b

Fig. 41 -4

Fig. 41 -5

Fig. 41 -6 a Baleen Humpback whale, a suspension feeder

Fig. 41 -6 b Leaf miner caterpillar, a substrate feeder Caterpillar Feces

Fig. 41 -6 c Mosquito, a fluid feeder

Fig. 41 -6 d Rock python, a bulk feeder

Fig. 41 -7 Small molecules Pieces of food Mechanical digestion Chemical digestion Nutrient (enzymatic hydrolysis) molecules enter body cells Undigested material Food 1 Ingestion 2 Digestion 3 Absorption 4 Elimination

Fig. 41 -8 Tentacles Food Mouth Epidermis Gastrovascular cavity

Fig. 41 -9 Gizzard Crop Esophagus Intestine Pharynx Anus Mouth Typhlosole Lumen of intestine (a) Earthworm Foregut Midgut Esophagus Hindgut Rectum Anus Crop Mouth Gastric cecae (b) Grasshopper Stomach Gizzard Intestine Mouth Esophagus Crop Anus (c) Bird

Fig. 41 -9 a Crop Esophagus Gizzard Intestine Pharynx Anus Mouth Typhlosole Lumen of intestine (a) Earthworm

Fig. 41 -9 b Foregut Midgut Esophagus Rectum Anus Crop Mouth (b) Grasshopper Hindgut Gastric cecae

Fig. 41 -9 c Stomach Gizzard Intestine Mouth Esophagus Crop Anus (c) Bird

Fig. 41 -10 Tongue Sphincter Salivary glands Oral cavity Salivary glands Mouth Pharynx Esophagus Sphincter Liver Stomach Ascending portion of large intestine Gallbladder Duodenum of small intestine Pancreas Small intestine Large intestine Rectum Appendix Cecum Anus Gallbladder Liver Pancreas Stomach Small intestine Large intestine Rectum Anus A schematic diagram of the human digestive system

Fig. 41 -10 a Tongue Sphincter Oral cavity Salivary glands Pharynx Esophagus Sphincter Liver Stomach Ascending portion of large intestine Gallbladder Duodenum of small intestine Pancreas Small intestine Large intestine Rectum Anus Appendix Cecum

Fig. 41 -10 b Salivary glands Mouth Esophagus Gallbladder Liver Pancreas Stomach Small intestine Large intestine Rectum Anus A schematic diagram of the human digestive system

Fig. 41 -11 -1 Food Epiglottis up Tongue Pharynx Esophageal sphincter contracted Glottis Larynx Trachea Esophagus To To lungs stomach

Fig. 41 -11 -2 Food Epiglottis up Tongue Pharynx Esophageal sphincter contracted Glottis Larynx Trachea Epiglottis down Esophagus To To lungs stomach Glottis up and closed Esophageal sphincter relaxed

Fig. 41 -11 -3 Food Epiglottis up Tongue Epiglottis up Pharynx Esophageal sphincter contracted Glottis Larynx Trachea Epiglottis down Esophagus To To lungs stomach Glottis up and closed Esophageal sphincter relaxed Glottis down and open Esophageal sphincter contracted Relaxed muscles Contracted muscles Sphincter relaxed Stomach

Fig. 41 -12 Esophagus Sphincter Stomach 5 µm Sphincter Interior surface of stomach Small intestine Folds of epithelial tissue Epithelium 3 Pepsinogen Gastric gland 2 HCl 1 Pepsinogen and HCl are secreted. Pepsin 2 HCl converts pepsinogen to pepsin. 1 Mucus cells Cl– 3 Pepsin activates more pepsinogen. H+ Chief cells Chief cell Parietal cells Parietal cell

Fig. 41 -12 a Esophagus Sphincter Stomach 5 µm Sphincter Interior surface of stomach Small intestine Folds of epithelial tissue

Fig. 41 -12 b Interior surface of stomach Epithelium 3 Pepsinogen 2 1 Pepsinogen and HCl are secreted. HCl Gastric gland 1 Mucus cells Pepsin Cl H+ – 2 HCl converts pepsinogen to pepsin. 3 Pepsin activates more pepsinogen. Chief cells Chief cell Parietal cells Parietal cell

Fig. 41 -13 Carbohydrate digestion Oral cavity, pharynx, esophagus Protein digestion Nucleic acid digestion Fat digestion Polysaccharides Disaccharides (starch, glycogen) (sucrose, lactose) Salivary amylase Smaller polysaccharides, maltose Stomach Proteins Pepsin Small polypeptides Lumen of small intestine Polysaccharides Pancreatic amylases Polypeptides Pancreatic trypsin and chymotrypsin DNA, RNA Fat globules Pancreatic nucleases Bile salts Maltose and other disaccharides Nucleotides Fat droplets Smaller polypeptides Pancreatic lipase Pancreatic carboxypeptidase Glycerol, fatty acids, monoglycerides Amino acids Epithelium of small intestine (brush border) Small peptides Disaccharidases Monosaccharides Dipeptidases, carboxypeptidase, and aminopeptidase Amino acids Nucleotidases Nucleosidases and phosphatases Nitrogenous bases, sugars, phosphates

Fig. 41 -13 a Carbohydrate digestion Polysaccharides Oral cavity, pharynx, esophagus (starch, glycogen) Disaccharides (sucrose, lactose) Salivary amylase Smaller polysaccharides, maltose Stomach Polysaccharides Lumen of small intestine Epithelium of small intestine (brush border) Pancreatic amylases Maltose and other disaccharides Disaccharidases Monosaccharides

Fig. 41 -13 b Protein digestion Stomach Proteins Pepsin Small polypeptides Pancreatic trypsin and chymotrypsin Lumen of small intestine Smaller polypeptides Pancreatic carboxypeptidase Amino acids Small peptides Epithelium of small intestine (brush border) Dipeptidases, carboxypeptidase, and aminopeptidase Monosaccharides Amino acids

Fig. 41 -13 c Nucleic acid digestion DNA, RNA Lumen of small intestine Pancreatic nucleases Nucleotidases Epithelium of small intestine (brush border) Nucleosides Nucleosidases and phosphatases Nitrogenous bases, sugars, phosphates

Fig. 41 -13 d Fat digestion Fat globules Bile salts Lumen of small intestine Fat droplets Pancreatic lipase Glycerol, fatty acids, monoglycerides

Fig. 41 -14 Liver Gallbladder Bile Stomach Secretin and CCK – Gastrin + CCK + Pancreas Duodenum of small intestine Secretin + Key CCK + + – Stimulation Inhibition

Fig. 41 -15 Microvilli (brush border) at apical (lumenal) surface Lumen Vein carrying blood to hepatic portal vein Blood capillaries Muscle layers Epithelial cells Basal surface Large circular folds Villi Epithelial cells Lacteal Key Nutrient absorption Intestinal wall Villi Lymph vessel

Fig. 41 -15 a Vein carrying blood to hepatic portal vein Muscle layers Large circular folds Villi Key Nutrient absorption Intestinal wall

Fig. 41 -15 b Microvilli (brush border) at apical (lumenal) surface Lumen Blood capillaries Epithelial cells Basal surface Epithelial cells Lacteal Villi Key Nutrient absorption Lymph vessel

Fig. 41 -16 Lumen of small intestine Triglycerides Fatty acids Monoglycerides Epithelial cell Triglycerides Phospholipids, cholesterol, and proteins Chylomicron Lacteal

Fig. 41 -17

Fig. 41 -18 Incisors Canines Premolars (a) Carnivore (b) Herbivore (c) Omnivore Molars

Fig. 41 -19 Small intestine Stomach Small intestine Cecum Colon (large intestine) Carnivore Herbivore

Fig. 41 -20 1 Rumen 2 Reticulum Intestine Esophagus 4 Abomasum 3 Omasum

Fig. 41 -21 Stimulus: Blood glucose level rises after eating. Homeostasis: 90 mg glucose/ 100 m. L blood Stimulus: Blood glucose level drops below set point.

Fig. 41 -22 100 µm

Fig. 41 -23 Ghrelin Insulin Leptin PYY

Fig. 41 -24 EXPERIMENT Obese mouse with mutant ob gene (left) next to wild-type mouse. RESULTS

Fig. 41 -24 a EXPERIMENT Obese mouse with mutant ob gene (left) next to wildtype mouse.

Fig. 41 -24 b

Fig. 41 -25

Fig. 41 -UN 1 Bloodstream Veins to heart Lymphatic system Hepatic portal vein Liver Stomach Mouth Esophagus Secretions from the gastric glands of the stomach Lipids Absorbed food Absorbed (except lipids) water Small intestine Anus Large Rectum intestine Secretions from the pancreas and the liver

Fig. 41 -UN 2