2. NOTES – DIGESTIVE SYSTEM ANATOMY

3. Within 2-6 hours, all food is emptied into the small intestine. After you eat how long does it take for the stomach to empty? Interesting Digestive System Facts

4. 1,100 How many pounds of food does the average person eat in a year?

5. about 20-30 ft long. How many feet long are your intestines?

6. Introduction The digestive system is used for breaking down food into nutrients which then pass into the circulatory system and are taken to where they are needed in the body.

7. Introduction There are four stages to food processing: 1. Ingestion: taking in food 2. Digestion: breaking down food into nutrients 3. Absorption: taking in nutrients by cells 4. Egestion: removing any leftover wastes

8. Oral Cavity Begins when food enters the mouth. (oral cavity) It is physically broken down by the teeth. It is begun to be chemically broken down by amylase, an enzyme in saliva that breaks down carbohydrates.

9. Tongue This is a muscle that: Positions food for chewing Mixes food with saliva Amylase is the enzyme that begins digestion Pushes chewed food (bolus) down the pharynx for swallowing

10. Teeth

11. Anatomy of a Tooth

12. Teeth Incisors Cuspid (canine) Bicuspids Molars

14. Tooth Decay

17. ROOT CANAL

18. Salivary Glands Parotid - ear, cheek Submandibular - below jaw Sublingual - under tongue

19. Salivary Glands Produce saliva which contains water to moisten Amylase to begin digestion Ions to neutralize food

20. Soft Palate This blocks the opening to the nasal passages to prevent food/liquid from entering.

21. Epiglottis Flap of skin that closes to prevent food from entering.

22. Pharynx Passageway for both food and air

23. Esophagus Muscular tube that carries the bolus of food from the pharynx to the stomach using involuntary contractions called peristalsis.

24. The bolus passes down the esophagus by peristalsis. Peristalsis is a wave of muscular contractions that push the bolus down towards the stomach.

25. Cardiac Sphincter Regulates the entry of the bolus into the stomach and prevents anything from going back with it is closed.

26. STOMACH

27. The Human Digestive System To enter the stomach, the bolus must pass through the lower esophageal sphincter, a tight muscle that keeps stomach acid out of the esophagus.

28. The Human Digestive System The stomach has folds called rugae and is a big muscular pouch which churns the bolus (Physical Digestion) and mixes it with gastric juice, a mixture of stomach acid, mucus and enzymes.

29. The Human Digestive System The acid kills off any invading bacteria or viruses. The enzymes help break down proteins and lipids. Chemical Digestion. The mucus protects the lining of the stomach from being eaten away by the acid.

30. The Human Digestive System The stomach does do some absorption too. Some medicines (i.e. aspirin), water and alcohol are all absorbed through the stomach. The digested bolus is now called chyme and it leaves the stomach by passing through the pyloric sphincter.

31. Stomach Lining Gastric Juices contain acids that break down food - secreted by gastric glands PEPSIN - most important digestive enzyme for breaking down food Mucus prevents stomach from digesting itself

32. Chyme - paste, after food has been broken down, released then into the duodenum via the pyloric sphincter valve Rugae - folds within stomach Gastric Pits contain glands to make juices

33. Pyloric Spincter Regulates the release of chyme (stomach contents) from the stomach into the first part of the small intestine called the duodenum. Once again…no return trip.

34. Small Intestine Starts at the pyloric sphincter 1. Duodenum 2. Jejunum 3. Ileum *Mesentery Membrane holds it together, contains blood vessels

35. Duodenum Where most chemical digestion takes place. This is where many chemical come together to break everything apart for reuse.

36. Duodenum Bile, produced in the liver but stored in the gall bladder, enters through the bile duct. It breaks down fats. The pancreas secretes pancreatic juice to reduce the acidity of the chyme.

37. 13. Liver Produces bile to physically break down lipids into smaller droplets. Bile is stored in the gall bladder until needed.

38. Liver 1 large right lobe | 1 smaller left lobe

39. Liver - ducts and vessels Hepatic duct --> to common bile duct Hepatic portal vein - circulates blood through liver

40. Liver Functions 1. blood glucose levels 2. breakdown of lipids and fats 3. protein metabolism 4. stores vitamins 5. destroys damaged RBCs 6. removes toxins 7. secretes bile

41. Remember Bili Lights? Using bili lights is a therapeutic procedure performed on newborn or premature infants to reduce elevated levels of bilirubin. If blood levels of bilirubin become too high, the bilirubin begins to dissolve in the body tissues, producing the characteristic yellow eyes and skin of jaundice.

42. 14. Gall Bladder - stores bile

43. 15. Bile Duct A tube that helps transport the bile from the gall badder to the duodenum.

44. 16. PANCREAS – secretes insulin which breaks down sugars Produces insulin and glucagon Pancreatic Juice also breaks down fat createsIons to maintain pH – neutralize acids

45. 17. Jejunum The jejunum is where the majority of absorption takes place. It has tiny fingerlike projections called villi lining it, which increase the surface area for absorbing nutrients.

46. Villi contain microvilli Each villi itself has tiny fingerlike projections called microvilli, which further increase the surface area for absorption.

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48. Ileum The last portion of the small intestine is the ileum, which has fewer villi and basically compacts the leftovers to pass through the cecum into the large intestine. Increased surface area increases the absorption rate.

49. Appendix What is it for anyway and why is it so dangerous?

50. The Human Digestive System The large intestine (or colon) is used to absorb water from the waste material leftover and to produce vitamin K and some B vitamins using the helpful bacteria that live here.

51. The Human Digestive System All leftover waste is compacted and stored at the end of the large intestine called the rectum. When full, the anal sphincter loosens and the waste, called feces, passes out of the body through the anus.

52. Digestion and Homeostasis The endocrine, nervous, digestive and circulatory systems all work together to control digestion. Before we eat, smelling food releases saliva in our mouths and gastrin in our stomachs which prepares the body for a snack. The Hormone Gastrin

53. Digestion and Homeostasis A large meal activates receptors that churn the stomach and empty it faster. If the meal was high in fat, digestion is slowed, allowing time for the fat to be broken down. Hence why we feel fuller after eating a high fat meal.

55. Acid Reflux Symptoms- burning sensation RX- avoid chocolate and peppermint, coffee, citrus, fried or fatty foods, tomato products – stop smoking- take antacids – don ’ t lay down 2-3 hours after eating. When small quantities of stomach acid are regurgitated into the esophagus

56. Inflammation of mucous membrane lining of stomach and intestine Common cause = Virus Symps – diarrhea and vomiting for 24-36 hours Complication = dehydration

57. Sore or lesion that forms in the mucosal lining of the stomach Cause – H. pylori (bacteria) is primary cause Lifestyle factors that contribute: cigarette smoking, alcohol, stress, certain drugs. Diagnosis – x-ray, presence of bacteria

58. A sac attached to the cecum and has no known function. When appendix becomes inflamed If it ruptures, bacteria from appendix can spread to peritoneal cavity. Symptoms- RLQ pain, rebound tenderness, fever, nausea, and vomiting RX - appendectomy

59. Infectious hepatitis Cause – virus Spread through contaminated food or H 2 O

60. Serum Hepatitis Caused by virus found in blood Transmitted by blood transfusion or being stuck with contaminated needles (drug addicts) Health care workers at risk and should be vaccinated

61. Chronic progressive disease of the liver Normal tissue replaced by fibrous connective tissue 75% caused by excessive alcohol consumption

62. Gallstones These “stones” are made of cholesterol crystals that can form in the gall bladder

63. Gallstones Can block the bile duct causing pain in the shoulder blades Small ones may pass on their own, large ones surgically removed Surgical removal of gallbladder = Cholecystectomy Cholecystitis: Inflammation of gallbladder.

64. DiarrheaConstipationJaundice Loose, watery, frequent bowel movements when feces pass along colon to rapidly Caused by infection, poor diet, nervousness, toxic substances or irritants in food When defecation delayed, feces becomes dry and hard RX –diet with cereals, fruits, vegetables, (roughage) drinking plenty of fluids, exercise, and avoiding tension Yellow color of the skin

65. Test Your Gray Matter Kenny is jaundiced. What could have caused this? The medical term that means inflammation of the mucous membrane lining of the stomach and intestines is: When small quantities of stomach acid are regurgitated into the esophagus, the resulting condition is called: Eating proper foods such as cereals, fruits, vegetables, and drinking plenty of fluids can help avoid what condition? The medical term that means surgical removal of the gallbladder is: What disorder would cause pain in the back between the shoulder blades? It is recommended that all healthcare workers be vaccinated for what disease? Hepatitis is caused by? A condition in which a sore or lesion forms in the mucosal lining of the stomachs called?