Animal Nutrition. Chapter 41. Biology Eighth Edition Neil Campbell and Jane Reece. PowerPoint Lecture Presentations for

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1 Chapter 41 Animal Nutrition PowerPoint Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp Copyright 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

2 Fig. 41-6a Four major feeding mechanisms Suspension Feeders Many aquatic animals are suspension feeders, which sift small food particles from the water Baleen Humpback whale, a suspension feeder

3 Fig. 41-6b Leaf miner caterpillar, a substrate feeder Substrate feeders are animals that live in or on their food source Caterpillar Feces

4 Fig. 41-6c Fluid feeders suck nutrient-rich fluid from a living host Mosquito, a fluid feeder

5 Fig. 41-6d Bulk feeders eat relatively large pieces of food Rock python, a bulk feeder

6 Essential Nutrients There are four classes of essential nutrients: Essential amino acids Essential fatty acids Vitamins Minerals 6 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

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

8 Table 41-1

9 Table 41-1a

10 Table 41-1b

11 Minerals Minerals are simple inorganic nutrients, usually required in small amounts 11 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

12 Table 41-2

13 Table 41-2a

14 Table 41-2b

15 Dietary Deficiencies Undernourishment is the result of a diet that consistently supplies less chemical energy than the body requires Malnourishment is the long-term absence from the diet of one or more essential nutrients 15 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

16 Concept 41.2: The main stages of food processing are ingestion, digestion, absorption, and elimination Ingestion is the act of eating Digestion is the process of breaking food down into molecules small enough to absorb In chemical digestion, the process of enzymatic hydrolysis splits bonds in molecules with the addition of water Absorption is uptake of nutrients by body cells Elimination is the passage of undigested 16 material out of the digestive compartment Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

17 Fig The four stages of food processing Small molecules Pieces of food Mechanical digestion Chemical digestion (enzymatic hydrolysis) Nutrient molecules enter body cells Food Undigested material 1 Ingestion 2 Digestion 3 Absorption 4 Elimination

18 Fig Crop Esophagus Gizzard Intestine Pharynx Anus Mouth Typhlosole Lumen of intestine (a) Earthworm Foregut Midgut Hindgut Esophagus Rectum Anus Crop Mouth (b) Grasshopper Mouth Gastric cecae Stomach Gizzard Intestine Variation in alimentary canals Esophagus Crop Anus (c) Bird

19 Concept 41.3: Organs specialized for sequential stages of food processing form the mammalian digestive system The mammalian digestive system consists of an alimentary canal and accessory glands that secrete digestive juices through ducts Mammalian accessory glands are the salivary glands, the pancreas, the liver, and the gallbladder 19 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

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

21 The Oral Cavity, Pharynx, and Esophagus The first stage of digestion is mechanical and takes place in the oral cavity Salivary glands deliver saliva to lubricate food Teeth chew food into smaller particles that are exposed to salivary amylase, initiating breakdown of glucose polymers The esophagus conducts food from the pharynx down to the stomach by peristalsis 21 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

22 Digestion in the Stomach The stomach stores food and secretes gastric juice, which converts a meal to acid chyme Gastric juice is made up of hydrochloric acid and the enzyme pepsin, which is produced by chief cells Parietal cells secrete hydrogen and chloride ions separately 22 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

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

24 Digestion in the Small Intestine The small intestine is the longest section of the alimentary canal It is the major organ of digestion and absorption 24 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

25 The first portion of the small intestine is the duodenum, where acid chyme from the stomach mixes with digestive juices from the pancreas, liver, gallbladder, and the small intestine itself The pancreas produces proteases trypsin and lipase, protein-digesting enzymes that are activated after entering the duodenum 25 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

26 Fig Gallbladder Bile Liver Stomach Secretin and CCK Gastrin + CCK + Duodenum of small intestine CCK + Secretin + CCK Cholecystokinin ( Key + Pancreas Hormonal control of digestion Stimulation Inhibition

27 Bile Production by the Liver In the small intestine, bile aids in digestion and absorption of fats Bile is made in the liver and stored in the gallbladder 27 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

28 Absorption in the Large Intestine The colon of the large intestine is connected to the small intestine The cecum aids in the fermentation of plant material and connects where the small and large intestines meet The human cecum has an extension called the appendix, which plays a very minor role in immunity 28 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

29 A major function of the colon is to recover water that has entered the alimentary canal Wastes of the digestive tract, the feces, become more solid as they move through the colon Feces pass through the rectum and exit via the anus 29 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

30 Concept 41.4: Evolutionary adaptations of vertebrate digestive systems correlate with diet Digestive systems of vertebrates are variations on a common plan However, there are intriguing adaptations, often related to diet 30 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

31 Some Dental Adaptations Dentition, an animal s assortment of teeth, is one example of structural variation reflecting diet Mammals have varying dentition that is adapted to their usual diet The teeth of poisonous snakes are modified as fangs for injecting venom All snakes can unhinge their jaws to swallow prey whole Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings 31

32 Fig Incisors Canines Premolars (a) Carnivore Molars Dentition and diet (b) Herbivore (c) Omnivore

33 Stomach and Intestinal Adaptations Herbivores generally have longer alimentary canals than carnivores, reflecting the longer time needed to digest vegetation 33 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

34 Fig Small intestine Small intestine Stomach Cecum Carnivore Colon (large intestine) Herbivore The alimentary canals of a carnivore (coyote) and herbivore (koala)

35 Fig Rumen 1 2 Reticulum Intestine Esophagus Many herbivores have fermentation chambers, where symbiotic microorganisms digest cellulose Abomasum 4 3 Omasum

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37 Thank you for your attention and participation!

38 You should now be able to: 1. Describe the four classes of essential nutrients 2. Distinguish among undernourishment, overnourishment, and malnourishment 3. Describe the four main stages of food processing 38 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

39 6. Follow a meal through the mammalian digestive system: Compare where and how the major types of macromolecules are digested and absorbed 7. Relate variations in dentition with different diets 39 Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings