Animal DigestionAnimal DigestionAnimal DigestionAnimal DigestionPrepared by: Steve GuzmanAnimals ingest their food in a variety of waysFigure 1: Suspension feeder; tube worm filtering food through its tentacleFigure 2: Substrate feeder; caterpillarcaterpillarFigure 3: Fluid feeder; mosquitoFigure 4: Bulk feeder; grey heronChemical digestionChemical digestionChemical digestionChemical digestion: the breakdown of large organic molecules to their componentsFigure 5: Chemical digestion: the breakdown of large organic molecules of their componentsOverview: Food processing occurs in four stagesDiagram 1: The four main stages of food processingDigestion occurs in specialized compartmentsDiagram 2: Digestion in the gastrovascular cavity of a hydraDigestion occurs in specialized compartments (cont.)Figure 6: Three examples of alimentary canalsThe human digestive system consists of an alimentary canal and accessory glandsDiagram 3: The human digestive systemDigestion begins in the oral cavityFigure 7: The human oral activityAfter swallowing, peristalsis moves food through the esophagus to the stomachDiagram 4: The human swallowing reflexAfter swallowing, peristalsis moves food through the esophagus to the stomach (cont.)Figure 8: Peristalsis moving a food bolus down the esophagusThe StomachDiagram 5: The stomach and its production of gastric juiceDigestive ailments include acid reflux and gastric ulcersFigure 9: Ulcer-causing bacteria, Helicobacter pyloriSources of Digestive Enzymes and BileFigure 10: The small intestine and related digestive organsDigestion in the Small IntestineTable 1Absorption in the Small Intestine Diagram 6: Structure of the small intestineOne of the liver’s many functions is processing nutrient-laden blood from the intestinesFigure 11: The hepatic portal systemThe large intestine reclaims water and compacts the fecesFigure 12: The relationship of the small and large intestineEvolutionary adaptation of vertebrate digestive systems often relate to dietFigure 13: The alimentary canal in a carnivore (coyote) and an herbivore (koala)herbivore (koala)Chemical energy powers the bodyTable 2An animal’s diet must supply essential nutrientsFigure 15: Obesity; a form of malnourishmentFigure 14: Anorexia; a form of undernourishmentVegetarians must be sure to obtain all eight essential amino acidsFigure 16: Essential amino acids from a vegetarian dietA healthy diet includes 13 vitamins and many essential mineralsFigure 17: Vitamin B12: a coenzyme in nucleic acid metabolism; maturation of red blood cells Figure 18: Calcium: Functions in bone and tooth formation, blood clotting, nerve and muscle functionWhat do food labels tell us?Figure 19: Whole wheat bread labelsThe human health problem of obesity may reflect our evolutionary pastFigure 21: A mouse with a defect in a gene for leptin, an appetite-suppressing hormone (left); a normal mouse right (right)Figure 20: Fat cells from the abdomen of a
View Full Document
Unlocking...