Animal Nutrition

1. Animal Nutrition

2. nutrition • Food taken in, taken apart and taken up • Herbivores – plants/algae • Carnivores – eat other animals • Omnivores – consume animals and plants/algae • Most animals are opportunistic – they will eat anything outside their diets when normal foods are not available.

3. Adequate diet • Must satisfy 3 nutritional needs • Chemical energy for chemical processes • Organic building blocks for macromolecules • Essential nutrients – preassembled organic molecules and minerals • Essential fatty acids • Essential amino acids • Vitamins • minerals Malnutrition – lacking 1 or more of the essential nutrients

4. Food processing – 3 steps • 1. ingestion – act of eating or feeding • 2. digestion – food broken down into molecules small enough for the body to absorb. • 3. absorption – take up of small molecules such as amino acids and simple sugars • Elimination – undigested material passes out of the digestive system

5. Digestion • Digestive enzymes (amylase) begin digestion in mouth. • Intracellular digestion – food vacuoles, paramecium • Extracellular digestion – • Gastrovascular cavity – hydra • Complete digestive tract – alimentary canal, mouth and anus

6. Figure 33.8 Tongue Oral cavity Salivary glands Mouth Pharynx Salivary glands Esophagus Esophagus Stomach Liver Gallbladder Sphincter Small intestine Gall- bladder Liver Sphincter Pancreas Large intestine Pancreas Stomach Small intestine Rectum Anus Large intestine Duodenum of small intestine Rectum Anus

7. Accessory glands of digestive system • Mouth – salivary glands (accessory) • Pancreas – endocrine gland • Liver – filters blood, produces bile • Gall bladder – stores bile, releases to S. Intestine Peristalsis – waves of contraction/relaxation to move food throughout alimentary canal. Sphincters – muscular rings that regulate passage to organs.

8. Oral cavity, pharynx and esophagus • Oral cavity – mouth, digestion begins • Tongue – helps shapes digested food into a ball – bolus • Pharynx – splits into 2 passages • Trachea – respiratory • Esophagus – leads to stomach

9. stomach • Stores food, begins digestion • Secretes components of a digestive fluid – gastric acid • HCL – makes pH around 2, denatures proteins • Pepsin – protein-digesting enzyme • Gastric acid does not affect cells lining stomach because of mucus released by cells • Gastric ulcers – damaged areas of stomach lining

10. stomach • Digestion occurs by churning of food (peristalsis) about every 20 seconds. • Chyme – acidic nutrient rich broth made from food • Stomach sphincters closed during digestion • Acid reflex – chyme backflows into esophagus “heartburn”

11. Digestion in Small Intestine • Most digestion of macromolecules from food, higher pH than stomach, trypsin enzymes • Longest part of alimentary canal, 20 feet, 6 meters • Duodenum, first 25 cm of small intestine, chyme mixes with digestive juices from pancreas, liver and gall bladder. • Bile – product of liver, contains bile salts

12. Absorption in the small intestines • Most absorption occurs across folded surface • Villi, microvilli • Surface area is roughly the size of a tennis court! • Increase rate of absorption

13. Absorption of large intestines • Includes the: • Colon – ascending, transverse, descending, recovers water • Cecum – pouch that ferments ingested material • Appendix – finger like extension of the human cecum, contains bacteria to break down material, accessory • Rectum – terminal portion, store feces until eliminated. Has two sphincters to regulate defecation • Irritation of lining of colon – diarrhea

14. Dental/mutualistic adaptations • Assortment of teach reflect the diet of the animal. • Mutualistic bacteria and protists live in some digestive organs of certain animals to help with digestion. • Koala – to break down eukalyptus • Ruminant digestion – 4 chambered stomach • Rabbits/rodents – bacteria in L.I • Termites – protists to help break down cellulose

15. Regulation of digestion • Nervous system involved by triggering of substances to be released (saliva, gastric juices) • Endocrine system – controls digestion with release of hormones released by stomach and duodenum. • Energy storage -