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2. M.Bregar (mbregar@gmail.com)2Digestive System: group of organs which processes food mechanically & chemically, so it can be absorbed into the circulatory system.Processing of food takes place across the alimentary canal in distinct stages. 3. M.Bregar (mbregar@gmail.com)3Events taking place can be classified as: 4. M.Bregar (mbregar@gmail.com)4The stages are: Ingestion: Food enters into the system.Digestion: Break down of food into simpler forms, allowing for absorption. Is both mechanical & chemical.Absorption: The movement of nutrients into the circulatory system. Means nutrients have entered into the blood.Egestion / Excretion: The elimination of waste materials. Any food material not processed is eliminated as fecal matter. 5. 5 6. M.Bregar (mbregar@gmail.com)6After ingestion, carries food through digestion until excretionFood is moved through the canal via smooth muscleVarious enzymes will enter into the tube at different points to process food chemically. 7. M.Bregar (mbregar@gmail.com)7The digestive system processes nutrients into more usable forms.Nutrients: any material needed by an organism to live and grow.Think of nutrients as providing the building materials & energy to make and sustain life. 8. 8 9. M.Bregar (mbregar@gmail.com)9Nutrients can be classified as:MicronutrientsMacronutrients Materials used by living organisms for growth & energy.Substances which help carry out metabolism including: VitaminsMineralsWater 10. M.Bregar (mbregar@gmail.com)10Macronutrients are broken down into 3 basic groups. 11. M.Bregar (mbregar@gmail.com)11ProteinsCarbohydrat esPreferred energy source. Known as saccharides (sugars: simple vs complex)Broken down into amino acids Used for growth, repair, and in lifeFats Known as lipids Used in making tissue & hormones. Important for bodys 12. M.Bregar (mbregar@gmail.com)12Breakdown of food into simpler forms by chemical means.For Example: Carbohydrates are broken down into simple sugars Proteins are broken down into peptides and amino acids Fats become emulsified, eventually forming fatty acids Chemical digestion is made possible by biological catalysts referred to as enzymes which are specific. 13. M.Bregar (mbregar@gmail.com)13M.Bregar (mbregar@gmail.com) 14. 14 15. M.Bregar (mbregar@gmail.com)15Enzymes are protein molecules which assist in carrying out metabolic activity (chemical reactions), including chemical digestion. 16. M.Bregar (mbregar@gmail.com)16Enzymes are involved in the catabolic (break down) and anabolic (building) reactions which take place in metabolism. 17. 17M.Bregar (mbregar@gmail.com) 18. M.Bregar (mbregar@gmail.com)18The speed at which a chemical reaction takes place is referred to as a rate of reaction.Reaction rates can be increased or decreased 19. Using HEAT to speed up reactions19 M.Bregar (mbregar@gmail.com) 20. SURFACE AREA & Chemical Reactions20 M.Bregar (mbregar@gmail.com) 21. M.Bregar (mbregar@gmail.com)21Problem: Why cant we use heat to speed up chemical reactions in the body? 22. M.Bregar (mbregar@gmail.com)22An enzymes 3 dimensional shape is key to enzymes completing activities. 23. M.Bregar (mbregar@gmail.com)23A protein whose shape has changed, loses its ability to function.This is called denaturationHuman proteins denature at _______________ 24. M.Bregar (mbregar@gmail.com)24At what temperature is enzyme activity optimal? 25. M.Bregar (mbregar@gmail.com)25What can you conclude about a thermophiles natural environment? 26. M.Bregar (mbregar@gmail.com)26The physical break down of food into smaller pieces.Purpose: to increase surface area, which increases reaction rates. 27. 27M.Bregar (mbregar@gmail.com) 28. M.Bregar (mbregar@gmail.com)28Ingestion takes place once food enters into the mouth. 29. M.Bregar (mbregar@gmail.com)29Mechanical Digestion begins in the mouth with masticatio n 30. M.Bregar (mbregar@gmail.com)30Many organisms use teeth to masticate food with the purpose of increasing surface area. 31. M.Bregar (mbregar@gmail.com)31There are different types of teeth 32. M.Bregar (mbregar@gmail.com)32Types of teeth found in an organism are a reflection of diet. 33. M.Bregar (mbregar@gmail.com)33The classes of teeth are: Canine Molars Pre-Molars IncisorsFunctions? 34. 34 35. The release of saliva, begins chemical digestion.35 36. M.Bregar (mbregar@gmail.com)36Saliva secretion is under the control of the autonomic nervous system.It is produced by the salivary gland. 37. M.Bregar (mbregar@gmail.com)37Produced by the salivary gland.Saliva is a mixture of water, mucus, saliva, enzymes, and antibacterial compoundsTissue involved? 38. M.Bregar (mbregar@gmail.com)38Main functions include: Chemicaldigestion of carbohydrates. Lubrication& Binding of Food into a Bolus Allowsfor tasting? 39. M.Bregar (mbregar@gmail.com)39Other functions, can include evaporative cooling and oral hygiene depending on species. 40. 40Food Leaves The MouthM.Bregar (mbregar@gmail.com) 41. 41The tongue shapes the food into a bolusThe bolus is pushed into the esophagus 42. M.Bregar (mbregar@gmail.com)42A muscular tube which connects the pharynx to the stomach. 43. M.Bregar (mbregar@gmail.com)43Made of smooth muscle.Peristalsis: the contraction of smooth muscle pushing food down into stomach.Voluntary or Involuntary? 44. 44DIGESTION & THE STOMACHM.Bregar (mbregar@gmail.com) 45. M.Bregar (mbregar@gmail.com)45A muscular bag (3 layers) lined with epithelial cells.Mechanical Digestion takes place as the food is churned. 46. M.Bregar (mbregar@gmail.com)46Rugae allow the stomach to stretch 47. M.Bregar (mbregar@gmail.com)47The stomach has the ability to stretch.Rugae Foldsof stomach wall lining Allows for increase in stomach volume 48. M.Bregar (mbregar@gmail.com)48As the stomach fills, receptors send impulses to the brain to indicate fullness 49. M.Bregar (mbregar@gmail.com)49Gastric glands in the stomach wall release gastric juice, so the stomach contains: Proteaseenzymes are released for the chemical digestion of proteins HydrochloricAcid: destroys bacteria, activates enzymes. The stomach is lined with protective mucus. 50. M.Bregar (mbregar@gmail.com)50The digested bolus is now called chyme, and is slowly released into the small intestine.The movement of chyme is regulated by sphincter muscles.Note: some absorption does occur 51. 51ABSORPTIONM.Bregar (mbregar@gmail.com) 52. M.Bregar (mbregar@gmail.com)52The intestines are classified into the small intestine and large intestine. 53. M.Bregar (mbregar@gmail.com)53The small intestine continues digestion and begins the process of absorption.The liver & pancreas help maximize absorption. 54. M.Bregar (mbregar@gmail.com)54Has 3 separate sections, each with unique function, they are the: Duodenum, Jejunum, Ileum. 55. M.Bregar (mbregar@gmail.com)55Chemical breakdown of chyme continues with the release of secretions from the pancreas and liver. 56. 56M.Bregar (mbregar@gmail.com) 57. M.Bregar (mbregar@gmail.com)57Secretions released include Bile Responsible for emulsifying lipids. Produced by the liver, stored in the gall bladderPancreatic Juice An alkaline mixture secreted by the pancreas, consists of: Enzymes Bicarbonate 58. M.Bregar (mbregar@gmail.com)58Bile contains various chemicals which can lead to the formation of gallstones. 59. 59M.Bregar (mbregar@gmail.com) 60. M.Bregar (mbregar@gmail.com)602nd largest organ in the body, with many additional functions, including: Waste BloodRegulationRegulation 61. M.Bregar (mbregar@gmail.com)61A multifunctional organ involved in the digestive and endocrine systems. 62. M.Bregar (mbregar@gmail.com)62Specific functions include: Digestive SystemSecretions complete the digestion of protein, carbohydrates, and fats. Secretions neutralize stomach acid.Endocrine System Secretes hormones that control blood sugar levels. Glucagon Insulin Somatostatin 63. M.Bregar (mbregar@gmail.com)63The location of the majority of absorption.Absorption is the movement of nutrients into the circulatory system 64. 64 65. M.Bregar (mbregar@gmail.com)65Inner surface of the small intestine are built to maximize absorption, they contain villi. 66. 66M.Bregar (mbregar@gmail.com)M.Bregar (mbregar@gmail.com) 67. M.Bregar (mbregar@gmail.com)67Contain blood vessels and lacteals: Lacteals: BloodVessels: 68. 68 69. M.Bregar (mbregar@gmail.com)69Final portion of the small intestine, absorption continues through villi.Leftovers (waste) are compacted, passing through the cecum into the large intestine. 70. M.Bregar (mbregar@gmail.com)70Main function is the absorption of water & electrolytes from the indigestible food.Vitamins: ___________ are absorbed.Mucus is secreted, binding the dehydrated waste into feces. 71. 71EGESTIONM.Bregar (mbregar@gmail.com) 72. 72 73. M.Bregar (mbregar@gmail.com)73After approximately 50 hours, egestion occurs at which point defecation occurs.Waste materials are eliminated in the form of feces. 74. M.Bregar (mbregar@gmail.com)74Final portion of large intestine, which is a temporary storage area for feces.When full, the anal sphincter looses, allowing feces to pass through the anus exiting the body.