Chapter 41

1. Chapter 41 Animal Nutrition

2. I. Homeostasis and Nutrition

3. A. Glucose Regulation • Lots of Glucose • Insulin is produced by the pancreas • Glucose can enter the cells easier and the liver makes glycogen • Glucose levels in the blood drop • Glucose gets low • Pancreas secretes glucagon which does the opposite of insulin • Glucose is released from glycogen stored

5. B. Nourishment • Undernourishment – body uses protein for fuel because it is not getting enough “energy” • Overnourishment – body is obese - if we eat lots of carbs it increases carb oxidation and fat is not used - leptin regulates fat levels

6. C. Essential Nutrients • Animal’s can not make these and must be consumed preassembled • Malnourished if missing one • 4 classes 1. Essential Amino Acids 2. Essential Fatty Acids 3. Vitamins 4. Minerals

7. 1. Essential Amino Acids • We can not make every amino acid we need • Animals produce complete proteins • Plants produce incomplete proteins

8. 8 Essential Amino Acids

9. 2. Essential Fatty Acids • Can’t make certain unsaturated fatty acids required for phospholipids • Deficiencies very rare

10. 3. Vitamins • Organic molecules needed in small amounts • Water soluble and fat soluble groups • 13 essential vitamins in humans

11. a. Some Water Soluble Vitamins • Niacin – component of NAD and NADH • Folic Acid – coenzyme on N.A. and A.A. metabolism • B12 – coenzyme in N.A. metabolism and needed for Red Blood Cells • C – collagen production and anti-oxidant (protects phospholipids)

12. b. Some Fat Soluble Vitamins • A – vision, skin, protects cell membrane • D – bone growth, absorption of Ca and P • E – antioxidant • K – blood clotting

13. 4. Minerals • Inorganic molecules needed in small amounts • Ca – bone, nerve and muscle function • P – bone, nucleotide • Cl and Na – nerve function • Fe – hemoglobin, electron carrier • F – maintenance of teeth • I – thyroid hormone

14. II. Food and Feeding • Herbivores, Carnivores, Omnivores • Most animals are opportunistic feeders • 4 types of feeders:

15. A. Types of Feeders • Suspension feeders – sift particles from water / clams and oysters • Substrate feeders – live on food source and eat through it / deposit feeder is one type / maggots and earthworms • Fluid feeder – suck nutrients from host / mosquitos and leeches • Bulk feeder – large pieces of food consumed / us

16. III. Basics of Digestion

17. A. 4 Parts to Digestion • Ingestion • Digestion – (enzymatic) hydrolysis • Absorption • Elimination

18. B. Types of Digestion • Intracellular – use food vacuoles and enzymes / protists • Extracellular - gastrovascular cavity = very simple with one opening / digestion and distribution of nutrients occurs here / cniderians and planarians - complete digestive tract = mouth and anus / one direction with special regions for digestion

19. Intracellular

20. Extracellular – Gastrovascular Cavity

21. Extracellular – Complete Digestive Tract

22. IV. Mammalian Digestive System

23. A. Oral Cavity • Physical and Chemical Digestion here • Teeth • 3 pairs of salivary glands • Saliva contains mucin, buffer, and salivary amylase • Forms bolus which is pushed to the pharynx by the tongue

24. B. Pharynx • Junction between the esophagus and trachea • Epiglottis found here which keeps food from entering the trachea

25. Esophagus • Moves food to stomach via peristalsis • Peristalsis – muscular pushing of food through digestive system • Top is striated (voluntary) and the bottom is smooth • Covered with mucus lining

27. D. Stomach • Stretchy • Secretes “gastric juices” • Pepsinogen (chief cells) is converted to pepsin by HCl which is made by the parietal cells • Pepsin is used to break down proteins • Coated in mucus (mucus cells) • Produces chyme • Top has the cardiac orifice and the bottom has the pyloric sphincter

29. E. Small Intestines • Basics - most hydrolysis and absorption of nutrients occurs here - starts with the duodenum where bile (fat digestion and bicarbonate) and pancreatic enzymes (pancreatic amylase, pancreatic lipidase, and trypsin) enter - jejunum and ilium are next / enzymes secreted here -Villi and microvilli absorb with small vessels of the lymphatic system called lacteal and blood vessels found inside - drain into the hepatic portal vessel heading to liver

30. Video

32. 2. Macromolecule Digestion • Carb digestion – salivary amylase, pancreatic amylase, maltase, sucrase, lactase • Protein digestion – pepsin, dipeptidases, aminopeptidase / trypsin, chymotrypsin, and carboxypeptidase are made by pancreas and turned into their active forms by enteropeptidase in the small intestines • Nucleic Acid digestion – nucleases • Fat digestion – lipase breaks it down after bile emulsification

34. F. Large Intestines • Cecum / appendix found here / may be large in some animals • Recovers water • Lots of mutualistic bacteria (E. coli) which produce vitamins • Rectum is the end with 2 sphincters, one involuntary and one voluntary

36. G. Hormones and Digestion • If you see food: - gastrin is made by the stomach and released into the blood stream - stomach secretes acids - if pH gets too low gastrin is stopped • Enterogastrones / Secretin and CCK - release bicarbonate and help break down A.A. and F.A.

37. V. Crazy Ways to Digest Cows, Rabbits, and Termites