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Nutrition & Digestion Digestion.

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Presentation on theme: "Nutrition & Digestion Digestion."— Presentation transcript:

1 Nutrition & Digestion Digestion

2 Section Objectives: Interpret the different functions of the digestive system organs. Outline the pathway food follows through the digestive tract. Identify the role of enzymes in chemical digestion.

3 Functions of the Digestive System
The main function of the digestive system is to disassemble the food you eat into its component molecules so that it can be used as energy for your body. Digestion is accomplished through a number of steps.

4 Digestion chemical process by which food is broken down into smaller molecules used by the body.

5 Digestion

6 Involves 3 activities: A. Mechanical digestion (chewing)
B. Chemical digestion C. Absorption

7 Structures of the digestive tract and their functions.
1. Mouth – chewing 1st place digestion begins. Saliva which contains a digestive enzyme, called amylase starts the process.

8 Digestion begins

9 3 Structures of Mouth A. Tongue - tastes 4 distinct tastes (bitter, salty, sour, sweet) B. Salivary glands - secrete saliva, start of digestive process. C. Teeth

10 Your Mouth Tonsils Teeth Tongue Incisors Gums Hard palate Soft palate
Uvula Tonsils Teeth Tongue Molars Bicuspids or premolars Opening of salivary gland duct Cuspids or canines

11 3 Types of teeth 1. Incisors - biting / tearing foods
2. Canines - tear / shred food 3. Molars - grind

12 For those who like a nice dip look at the above oral cancers of the mouth and tongue!!


14 2. Pharynx area in back of the throat that connects the nose and the mouth to the digestive and respiratory tract.

15 3. Esophagus tube that carries food to the stomach.
Epiglottis - a small flap of tissue that seals off the trachea during the swallowing of food.

16 4. Stomach pouch like structure with thick expandable muscular walls.
Hydrochloric acid increases the acidity of the stomach contents to pH2.

17 Ulcer Causing Bacteria

18 Polyps in the stomach

19 Heartburn

20 Stomach A. Contains HCl, the enzyme pepsin for digestion of proteins Both are produced by the glands of the stomach for breaking down food.

21 Stomach B. Growling of the stomach is the contractions of the stomach as it mixes the food, etc. When there is less food the noise is louder.

22 Stomach C. Mucus - coats the stomach wall for protection and helps to lubricate and ease movement of food.

23 Ulcers

24 5. Small intestine A tube about 7 m long that digests carbohydrates, fats completes digestion of proteins and absorbs digested nutrients. 2.5 cm in diameter. Polyp in small intestine

25 3 parts of small intestine


27 Small Intestines

28 5. Small Intestines cont. A. Villi - fingerlike projections in the small intestine that help increase the surface area for absorption. Folds of the small intestine



31 5. Small Intestines B. Bile - a salt containing a detergent that is secreted into the small intestine by the gall bladder. Bile helps to break up fats.

32 Appendix fingerlike structure found near the junction in the small and large intestine. Appendicitis - when appendix becomes inflamed. Treatment is the removal of the appendix.

33 Appendix annimation

34 Appendics

35 Large Intestines


37 6. Large Intestine A large tube in diameter about 1.5 m long that absorbs water from the material remaining in the digestive tract.

38 Colon Cancer

39 Large Intestine A. Peristalsis - wavelike movement that moves materials. Other places that this movement occurs is in the esophagus and small intestines.

40 Premalignant polyps colon

41 Large Intestine B. Feces - undigested solid waste material emitted.

42 Large Intestine C. Bacteria - found in the large intestine, aids in digestion. Takes hours for food to move from mouth to anus.

43 Sigmoid Colon Hiatal Colon Reflex

44 7. Pancreas secretes pancreatic fluid into the small intestine.
Helps digest fats, proteins, and carbohydrates. Pancreatic fluid is a mixture of enzymes and sodium bicarbonate. Insulin controls the uptake of glucose by the cells.

45 8. Liver Largest internal organ, serves as the body’s primary storage place main chemical factory and detoxification site. Gets blood from intestines before the blood goes to the rest of the body. Cross-section of a normal liver. The holes are bile ducts.

46 2 lobes of the liver

47 Liver Hepatitis - infection of the liver by a virus. Can be sexually transmitted, by blood products, or feces. Hepatic Cell Carcinoma

48 Liver Cirrhosis - scarring of the liver, can be caused from Hepatitis or alcoholism. Results can be death. Cirrhosis

49 9. Gall Bladder stores bile made by the liver. Takes water from solution making bile more concentrated. Bile then is released into small intestine as needed. stone that stuck into the cystic duct Gall stones

50 Gall Bladder cont. Calcified Stones taken out from surgically removed


52 Answer Oral Cavity Mouth Salivary Glands Pharynx Esophagus Liver
Stomach Gall Bladder Pancreas Small Intestine Large Intestine Rectum Anus

53 Eating the American Way

54 Nutrition

55 Section Objectives: Recognize the contribution of the six classes of nutrients to body nutrition. Identify the role of the liver in food storage. Relate caloric intake to weight loss or gain.

56 The Vital Nutrients Six basic kinds of nutrients can be found in foods: carbohydrates, fats, proteins, minerals, vitamins, and water. You supply your body with these nutrients when you eat foods from the five main food groups.


58 Nutrients Substances needed for: Obtained from the food we eat
Cell repair/Maintence Cell growth Energy Obtained from the food we eat

59 Diet -Digestive

60 6 Main Nutrients A. Carbohydrates B. Fats/Lipids C. Proteins
D. Vitamins E. Minerals F. Water

61 A. 3 Carbohydrates

62 1. Sugars A. Glucose - sugar cells obtain most of their energy from C6H12O6. B. Glycogen - made up of thousands of glucose units. (Body stores glycogen in the liver and muscles, if an excess then stored as fat.)

63 2. Starches made of many sugars. Aka complex carbs.
Ex: Breads, pasta and potatoes.

64 3. Cellulose/Fiber contained in cell walls of plants. Fiber that aids in digestion. May help provide some protection against heart disease and some types of cancer.

65 B. Fats - Lipids store other nutrients and are a source of stored energy. Made of three fatty acids joined by glycerol molecule. Use lipids to make cell membranes, hormones, oils in hair and skin. Two types - Saturated and Unsaturated fats. (Unsaturated fat is considered the healthier of the two, because it is liquid at room temperature.)

66 C. Proteins the construction materials for the body parts such as muscle, skin and blood. 1. Amino Acids - make up proteins. There are 20 Amino Acids Note: Essential amino acids can not be made by the body, there are eight of these. A proper diet would provide these for the body. Foods such as meats, eggs and dairy products contain them.

67 Minerals and vitamins Fluorine (F) Calcium (Ca) Iodine (I)
Phosphorus (P) Iron (Fe) Copper (Cu) Sodium (Na) Potassium (K) Magnesium (Mg) Sulfur (S)

68 D. Vitamins complex organic molecules that are needed by the body in very small amounts. Two types: 1. Water soluble - dissolve in water. Cannot be stored in the body, so must have regularly. Ex: B1(Thiamin), B2 (Riboflavin), Niacin, B6, B12, C. 2. Fat Soluble - stored in fat or liver for future use by the body. Ex: Vit. A, D, E, K

69 This table lists foods that contain fat-soluble and water-soluble vitamins.
Function Source Fat-soluble A Maintain health of epithelial cells; formation of light absorbing pigment; growth of bones and teeth Liver, broccoli, green and yellow vegetables, tomatoes, butter, egg yolk D Absorption of calcium and phosphorus in digestive tract Egg yolk, shrimp, yeast, liver, fortified milk; produced in the skin upon exposure to ultraviolet rays in sunlight E Formation of DNA, RNA, and red blood cells Leafy vegetables, milk, butter Green vegetables, tomatoes, produced by intestinal bacteria K Blood clotting

70 Minerals and vitamins Vitamins Function Source Niacin
Water-soluble B1 Sugar metabolism; synthesis of neurotransmitters Ham, eggs, green vegetables, chicken, raisins, seafood, soybeans, milk B2 (riboflavin) Sugar and protein metabolism in cells of eyes, skin, intestines, blood Green vegetables, meats, yeast, eggs Niacin Energy-releasing reactions; fat metabolism Yeast, meats, liver, fish, whole-grain cereals, nuts B6 Fat metabolism Salmon, yeast, tomatoes, corn, spinach, liver, yogurt, wheat bran, whole-grain cereals and bread

71 Protein metabolism; wound healing
Minerals and vitamins Vitamins Function Source Water-soluble B12 Red blood cell formation; metabolism of amino acids Liver, milk, cheese, eggs, meats Pantothenic acid Aerobic respiration; synthesis of hormones Milk, liver, yeast, green vegetables, whole-grain cereals and breads Folic acid Synthesis of DNA and RNA; production of red and white blood cells Liver, leafy green vegetables, nuts, orange juice Biotin Aerobic respiration; fat metabolism Yeast, liver, egg yolk C Protein metabolism; wound healing Citrus fruits, tomatoes, leafy green vegetables, broccoli, potatoes, peppers


73 E. Minerals inorganic substances that perform vital functions in the body. Calcium - found in dairy products . Necessary for strong bones and teeth, muscle and nerve activity and blood clotting. Potassium , Sodium , and Magnesium - Necessary for nerve and muscle activity.

74 F. Water necessary for life. Lose 3-5 liter of water a day through sweat , urine, etc. About 67% of your body mass is water. 90% of the plasma is water.

75 F. Water 3 Functions: 1. To transport nutrients and wastes
2. Cool body 3. Necessary for chemical reactions.

76 Nutrition

77 Metabolism sum of all the chemical processes that take place within an organism.

78 Energy ability to do work.

79 Calorie amount of heat energy needed to raise the temperature of 1 gram of water by 1oC Measurement for energy.

80 Calories and Metabolism
The energy content of food is measured in units of heat called Calories, each of which represents a kilocalorie, or 1000 calories. Some foods, especially those with fats, contain more Calories than others.

81 Metabolic Rate Basal Metabolic Rate (BMR) - rate of metabolism at rest. BMR is equal to the numbers of kilocalories an animal uses in a set amount of time to maintain homeostasis.

82 Calculate your BMI -

83 Diseases and Conditions

84 4 Diseases from poor nutrition
1. Scurvy - caused from a lack of Vit. C disease sailor once got because of the long voyage and poor diet.

85 Scurvy - vitamin C deficiency.
The effects of scurvy

86 4 Diseases from poor nutrition cont.
2. Night Blindness - caused from lack of Vit. A 3. Beriberi - Lack of B1. Most common in Asia where diet is mainly rice. 4. Rickets - caused from lack of Vit. D. Rickets

87 2 Eating Disorders 1. Bulimia - consume lots of food, but then binge. Possible problems, swollen salivary glands, kidney, liver and pancreas problems, tooth decay from stomach acid. 2. Anorexia - over exercise, but does not eat. Starvation occurs.

88 Digestion and the Human body

89 Endocrine System

90 Endocrine glands series of ductless glands that release chemicals (hormones ) directly into the blood stream.

91 Hormones Chemicals released in one part of an organism that affects another part. (Chemical messengers)

92 Two groups of hormones based on how they act on their target cells.
A. Amino acid hormones - amino acids make proteins. B. Steroid hormones - made from lipids . Can alter genetic activity of some cells.

93 Hypothalamus - portion of the brain that controls the pituitary gland.
Indirectly controls growth, development and activities of the reproductive system.

94 Negative feedback system -
self regulating system of the endocrine system. As the hormone increases level in the blood production of the hormone at the gland decreases. (equilibrium)

95 Oxytocin - for uterus contraction during birth. (stored in the posterior pituitary gland)

96 Pituitary gland - master endocrine gland - growth hormone produced here. Indirectly controls growth, development and activities of the reproductive system. Controls many other glands.

97 Endocrine System

98 hGH - human growth hormone -
stimulates division and growth of bone, muscle, and other body cells. Stimulates liver cells to release glucose (for energy) into blood during times of growth.

99 Robert Pershing Wadlow - Giant
Robert Pershing Wadlow was born on Feb. 22, 1918 in Alton, Illinois. At the time of his death at age 22, he was 8' 11.1" tall & 490 pounds, which made him the tallest person in history according to the Guinness Book of Records.

100 His parents, Addie and Harold Wadlow, always loved & protected him to the best of their abilities, honoring his desire to be treated as a "normal" person. They even destroyed his personal belongings after his death so that no one could profit from the exploitation of them. Robert promoted the International Shoe Company, which provided his size 37 shoes to him for free. Traveling for the shoe company, he visited over 800 towns and 41 states.

101 Robert's size was attributed to an overactive pituitary gland, which produced much higher than normal levels of growth hormone. Because of the extremely long legs caused by pituitary giantism, he had little sensation in his feet and did not feel any chafing until blisters formed. While making an appearance in 1940, a fatal infection set in when such a blister formed due to the braces he had to wear to strengthen his overly long legs. On the 15th of July, Robert Wadlow passed away in his sleep from the infection.


103 TSH - thyroid stimulating hormone -
stimulates development and activity of thyroid gland.

104 FSH - follicle stimulating hormone -
stimulates gonads to produce egg and sperm. Triggers puberty.

105 LH - Luteinizing hormone -
stimulates gonads to produce sex hormones. Triggers puberty.

106 Thyroid Gland - makes a hormone that speeds up metabolism, growth and development. If thyroid malfunctions, may feel tired . May also gain weight.

107 Goiter - Growth caused by a malfunction of the thyroid gland.

108 Adrenal gland - located on top of the kidneys. Release hormones that prepare your body for stressful situations.

109 Epinephrine (ep uh NEF run )
often called adrenaline.

110 Norepinephrine These hormones used during the fight or flight response.

111 Parathyroid gland - produces Parathyroid hormone - increases the rate of calcium , phosphate, and magnesium absorption in the intestines, etc.

112 Ovary - secretes female sex hormones (steroid) Ovary releasing ovum

113 Estrogen - Primary female hormone maintains female reproductive cycle .

114 Progesterone - female hormone. Prepares and maintains uterus during pregnancy.

115 Testis - secretes male sex hormones (steroid)

116 Testosterone - Primary male hormone maintains reproductive cycle.

117 Pancreas - helps regulate the sugar levels in body.

118 Insulin - hormone that stimulates cells to take up sugar from the blood. (part of digestive and endocrine system)

119 Glycogen - produced by alpha cells in the islets of Langerhans. Helps provide body with energy.

120 Diabetes - disorder of pancreas. Some symptoms are excess sugar in blood, intense thirst, weakness and excessive urination.

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