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PowerPoint Presentation - The Human Digestive System

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Title: PowerPoint Presentation - The Human Digestive System Author: jeff Last modified by: Personal Created Date: 12/2/2003 3:33:23 AM Document presentation format – PowerPoint PPT presentation

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Title: PowerPoint Presentation - The Human Digestive System


1
Why do we eat?
2
Food tests
  • Food type
  • Test





  • Protein
  • Sugar
  • Fat
  • Carbohydrate
  • Biuret turns purple if protein is present
  • Benedicts turns from blue to red/brown if sugar
    is present
  • Greaseproof paper gets an oily residue
  • Iodine turns blue/black if starch is present

3
Carnivore
  • Only eats meat
  • E.g. Spider, lion
  • Its survival is dependent on finding and catching
    prey

Top predator Nothing eats him!
4
Carnivore Teeth Adaptation
5
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6
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7
Herbivore
  • Only eats plants
  • E.g. Cow, aphid
  • Depends on a large supply of plant matter.
  • Longer gut as less energy available in their
    food.

8
Herbivore Teeth Adaptation
9
Omnivore
  • Eats a mixture of plants and animals
  • E.g. Pigs, humans
  • Increased chance of survival as they are not
    restricted to one diet.

10
Decomposers
  • Breaks down and recycles dead material.
  • E.g. Bacteria, fungi

11
Primary Producers (Plants)
  • Plants can make their own food using
  • Sunlight
  • Chlorophyll
  • Water
  • Carbon dioxide
  • How are all the consumers and producers linked?

12
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13
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14
Path of digestion
15
The Digestive System
(Breaking food down into smaller pieces)
Lets find out what happened to your breakfast
today!
  • Mouth
  • esophagus
  • Stomach
  • Small Intestine
  • Liver
  • Large Intestine
  • Gall Bladder
  • Pancreas
  • Rectum
  • Anus

16
1. mouth- releases saliva- moistens food
17
  • chemical digestion
  • enzyme- protein speeds chemical reactions
  • mechanical digestion- teeth

18
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19
Mouth
  • Teeth
  • (mechanical breakdown)
  • Incisors used for cutting
  • Canines used for stabbing and holding
  • Molars large surface area used for grinding
  • Saliva
  • (chemical breakdown)
  • Enzyme (speeds up reactions in the body)
  • Breaks down carbohydrate

20
2. esophagus
  • muscular tube - connects mouth? stomach
  • lined w/ mucus

21
flap of tissue that seals off windpipe-prevents
food from entering lungs
22
2. esophagus
  • peristalsis involuntary waves of muscle
    contractions that move food ? stomach

23
esophagus
  • Approximately 25cm long
  • Moves food from the throat to the stomach
  • Muscle movement called peristalsis
  • If acid from the stomach gets in here thats
    heartburn.

24
3. stomach-
  • most mechanical digestion occurs here
  • some chemical digestion
  • enzymes- pepsin
  • hydrochloric acid

25
Mechanical digestion in the stomach is like the
clothes and soapy water mix in a washing machine.
YouTube video-digestion
26
Stomach
  • Stores the food you eat
  • Chemically breaks it down into tiny pieces
  • Mixes food with digestive juices
  • Acid in the stomach kills bacteria

27
small intestine
  • most chemical digestion absorption takes place
    here
  • receives bile

28
small intestine
  • lined with villi
  • absorb nutrient molecules

Millions of tiny finger shaped structures called
villi (villus) cover the surface of the small
intestine.
29
Small Intestine
  • Small intestines are roughly 6 metres long.
  • Enzymes and bile are added.
  • Villi increase the surface area to help
    absorbtion.
  • Nutrients from the food pass into the bloodstream
    through the small intestine walls.

30
liver
  • in upper portion of abdomen
  • makes bile breaks up fat

31
Liver
  • Directly affects digestion by producing bile
  • Bile is an enzyme that helps dissolve fat
  • Processes nutrients in the blood, filters out
    toxins and waste.
  • Is often called the bodys energy factory

32
gallbladder
  • stores bile

33
Gall Bladder
  • Stores bile from the liver
  • Delivers bile when food is digested
  • Fatty diets can cause gallstones

34
pancreas
  • between stomach small intestine
  • produces enzymes - break down starches, proteins
    fats

35
Pancreas
  • Produces compounds to digest fats and proteins
  • Neutralizes acids that enter small intestine
  • Regulates blood sugar by producing insulin

36
large intestine
  • last part of digestive system
  • contains bacteria that make Vitamin K
  • absorbs water
  • eliminates remaining material

37
large intestine
  • ends in short tube-rectum

38
Large Intestine
  • About 1.5 metres long
  • Accepts what small intestines dont absorb.
  • Absorbs water and minerals from the waste matter.
  • Absorption means taking into the body via the
    blood stream.

39
anus
  • muscular opening _at_ end of rectum

40
Rectum and Anus
  • Rectum
  • About 15cm long
  • Stores waste before egestion.
  • Anus
  • Muscular ring that controls egestion.

41
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42
mouth
epiglottis
esophagus
liver
stomach
gallbladder
large intestine
small intestine
anus
appendix
43
Write the name of each colored organ
  • Green
  • Red
  • Pink
  • Brown
  • Purple
  • Green
  • Yellow

44
Answers
  • Green Oesophagus
  • Red Stomach
  • Pink Small Intestine
  • Brown Large Intestine
  • Purple Liver
  • Green Gall Bladder
  • Yellow Pancreas

45
  • What are nutrients?
  • Essential substances that your body needs in
    order to grow and stay healthy
  • Six categories of nutrients
  • Carbohydrates
  • Fats
  • Proteins
  • Vitamins
  • Minerals
  • Water

46
6 Key Nutrients
  • Carbohydrate
  • Fat
  • Protein
  • Vitamins
  • Minerals
  • Water
  • C ould
  • F anny
  • P lay
  • V iolin
  • M uch
  • W orse

47
Energy content of food
1 gram of protein equals 5.65kcal of energy
1 gram of fat equals 9.4kcal of energy
1 gram of carbohydrate equals 4.15kcal of energy
48
Energy efficiency
Gross energy
Heat
gases
Energy used
urine
faeces
No animal is able to utilise all the energy in
its food !
49
Energy Needs
  • Body Size
  • Body composition
  • Degree of exercise
  • Physiological state and
  • Ambient temperature

50
Carbohydrates
  • All carbohydrates are composed of carbon,
    hydrogen, and oxygen in a 121 empirical ratio.
  • The general empirical formula for a carbohydrate
    is CH2O.
  • If a carbohydrate has 5 carbons atoms,
    what would be its empirical formula?
  • If a carbohydrate has 12 hydrogen atoms
    present, what would be its empirical formula?
  • C5H10O5

C6H12O6
51
Carbohydrates
  • Carbohydrates
  • Structure and function Carbohydrates are sugars
    and starches that the body uses for ENERGY!
  • PLANTS are the major source of carbohydrates in
    the food we eat.
  • Simple Carbohydrates
  • Sugars that are quickly digested and provide a
    BOOST of energy for the body
  • Foods with LOTS of sugar oranges, milk, cookies,
    candy
  • 1

52
Carbohydrates
  • Complex Carbohydrates
  • Starches that are composed of many sugars linked
    together
  • They provide the body with long-term energy since
    they are digested more slowly than sugars.
  • Foods with LOTS of starch
    rice, beans, potatoes
  • 1

53
JOBS OF CARBOHYDRATES ENERGY major
job provides 4 calories per gram Not enough
carbs eaten lose weight Too many carbs eaten
gain weight
54
Fiber in foods is another part of the
carbohydrate family. Fiber, or cellulose,
does not completely digest We need it to
1. help the body digest other foods and 2.
to help eliminate waste-- (NATURES BROOM)
Examples of fiber are strings in celery, pulp
of oranges, peel of apples, etc.
55
Have You Had Your Fiber Today?
56
Nutritional concerns of lack of carbohydrates in
diet symptoms TIRED
57
Fat
  • Functions
  • ENERGY source for the body (more than carbs and
    proteins)
  • Help protect and cushion vital organs as well as
    joints
  • Insulate the body
  • .
  • 1

58
JOBS OF FAT
  • 1. ENERGY 9 CALORIES PER GRAM
  • 2. PROVIDE BODY HEAT, INSULATE
  • 3. CARRIES FAT SOLUBLE VITAMINS TO THE CELLS
  • 4. ADD FLAVOR TO FOOD
  • 5. SATIETY VALUE makes you feel full longer

59
Fat
  • Unsaturated fats
  • At room temperature, they are typically in liquid
    form.
  • They are less harmful to the circulatory system
    than saturated fats.
  • Foods with a lot of unsaturated fat canola,
    safflower, and peanut oils
  • 1

60
Fat
  • Saturated fats
  • At room temperature, they are typically in solid
    form.
  • Diets with TOO MUCH saturated fat have been known
    to cause heart disease.
  • Foods with a lot of saturated fat beef fat, egg
    yolks, dairy products
  • 1


61
FAT is both a nutrient and a foodbutter on bread
is an example of eating fat. Fat is sometimes
hidden in foodexamples salad dressing,
gravy, sour cream, cookies, pies, cakes
62
Saturated fat is SOLID at room temperature.
(notice Ss in saturated and solida clue to help
you remember!) Unsaturated fat is LIQUID at room
temperature.
63
Fat food sources butter, lard fat present in
meat bacon oils of all kinds egg yolks dairy foods
64
Protein
  • Proteins
  • Function Provide the building materials your
    body needs to grow and repair itself
  • 1

65
JOBS OF PROTEIN
  • BUILD AND REPAIR BODY TISSUE is the main job.
  • Energy 4 calories per gram
  • (What other nutrient also provides 4 calories of
    energy per gram?)
  • CARBOHYDRATES

66
Calories
  • What is a calorie?
  • The energy obtained from carbohydrates, proteins,
    and fats is measured in units called calories.

67
Food
  • Type
  • Use
  • Carbohydrate
  • Fat
  • Protein
  • Sugars
  • Long term energy
  • Protecting organs and long term energy store
  • Making muscle, enzymes, skin, hair
  • Fast energy

68
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70
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71
Vitamins and Minerals
  • Vitamins and minerals are essential for the
    maintenance of good health and the prevention of
    a number of diseases.

72
Vitamins
  • Vitamins are naturally occurring organic
    compounds that are essential to metabolic or
    other functions in the body.
  • Most vitamins cannot be synthesized by the body.
    They must be supplied in the diet.
  • Vitamins are usually classified as water soluble
    or fat soluble
  •  

73
Minerals
  • Minerals are inorganic and are found in the soil
    and water absorbed by plants or eaten by animals.
  • The human body requires substantial amounts of
    minerals on a daily basis to ensure proper
    functioning of the organs, bones, tissue and
    immune system.

74
Minerals
  • Trace Minerals
  • Macro-minerals

75
Minerals
Mineral Mineral What the mineral does Food sources
Sodium Sodium Fluid and electrolyte balance, supports muscle contraction and nerve impulse transmissions salt, soy sauce, bread, milk, meats
Chloride Chloride Maintains fluid and electrolyte balance, aids in digestion salt, soy sauce, milk, eggs, meats
Potassium Potassium Maintains fluid and electrolyte balance, cell integrity, muscle contractions and nerve impulse transmission potatoes, vegetables, banana, strawberries, cod, milk
Calcium Calcium Formation of bones and teeth, supports blood clotting milk, yogurt, cheddar cheese, Swiss cheese, tofu, sardines, green beans, spinach, broccoli
Phosphorus Phosphorus Formation of cells, bones and teeth, maintains acid-base balance all animal foods (meats, fish, poultry, eggs, milk)
Magnesium Magnesium Supports bone mineralization, protein building, muscular contraction, nerve impulse transmission, immunity Green vegetables, tomato juice, beans, cashews, halibut
Iron Iron Part of the protein hemoglobin (carries oxygen throughout body's cells) spinach, broccoli, green beans, tomato juice, beef liver

76
Minerals
Mineral Function Food sources
Zinc Enzymes production of genetic material/proteins, vitamin A transport, wound healing, sperm production and the normal development of the fetus  Green vegetables, tomato juice ,lentils, oysters, shrimp, crab, meats yoghurt, cheese
Selenium Antioxidant,  works with vitamin E to protect body from oxidation seafood, meats and grains
Iodine Thyroid hormones regulate growth, development and metabolic rate salt, seafood, bread, milk, cheese
Copper Absorption/utilization of iron, formation of hemoglobin , enzymes meats, water
Manganese Facilitates many cell processes widespread in foods
Fluoride formation of bones and teeth, helps to make teeth resistant to decay fluoridated drinking water, tea, seafood
Chromium Associated with insulin and is required for the release of energy from glucose vegetable oils, liver, whole grains, cheese, nuts
Molybdenum Facilitates many cell processes legumes, organ meats
76
77
Vitamin Characteristics
  • Each vitamin has one or more specific purposes.
  • Vitamins are essential to life processes.
  • Vitamins are generally used by the body with very
    minimal changes
  • Vitamins are usually required in only small
    amounts
  • Most vitamins cannot be synthesized by the body
    directly

77
78
Important Vitamins
Vitamin Function Source
A Retinol Supports vision, skin, bone and tooth growth, immunity and reproduction mango, broccoli, butternut squash, carrots, tomato juice, sweet potatoes, pumpkin, beef liver
C Ascorbic Acid Collagen synthesis, amino acid metabolism, helps iron absorption, antioxidant Fruits and vegetables
D Promotes bone mineralization Self-synthesis milk, egg yolk, liver, fatty fish
B12 New cell synthesis, Breaking down fatty acids / amino acids, nerve cell maintenance Meats, poultry, fish, shellfish, milk, eggs
E Antioxidant, regulation of oxidation reactions, supports cell membrane stabilization Shrimp, cod, wheat germ, tofu, polyunsaturated vegetable oils, sweet potatoes,
K Synthesis of blood-clotting proteins, regulates blood calcium Liver, leafy green vegetables, spinach, broccoli, cabbage,
78
79
Vitamin C Sources
  • Vitamin C is found in many fresh fruits and
    vegetables.
  • . Cooking vegetables in water tends to leach the
    vitamin from the food.
  • Cooked foods also contain less vitamin C, since
    it is also easily oxidized and hence destroyed in
    the cooking process.
  • Aid in healing wounds and helping to prevent
    bacterial infections

79
80
Vitamin C Deficiencies
  • Scurvy or Scorbutus.
  • Symptoms include
  • swollen legs,
  • rotting gums,
  • and bloody lesions.
  • Common among sailors in the 18th and 19th
    centuries who spent a long time at sea without
    fresh fruits and vegetables

80
81
Vitamin A Sources
  • Commonly found in cod liver oil, green
    vegetables, and fruit.
  • Carrots indirectly serve as a source of vitamin A
    since they contain b carotene which the body
    readily converts to vitamin A

81
82
Vitamin A Functions
  • Vitamin A is fat soluble.
  • It is not readily broken down by cooking.
  •  Role in aiding in night vision.

82
83
Vitamin A Deficiencies
  • A deficiency in vitamin A results in night
    blindness.
  • The most serious deficiency results in a
    condition known as Xeropthalmia, a severe form of
    conjunctivitius or blindness.

83
84
Vitamin D - Sources
  • Vitamin D is commonly found in fish liver oil as
    well as egg yokes.
  • Unlike other vitamins, the body synthesizes
    vitamin D in the skin through the action of
    ultraviolet light

85
Vitamin D Functions
  • Vitamin D is an important regulator of calcium
    metabolism.
  • It is involved in the uptake of calcium and
    phosphate ions from food into the body.
  • It is necessary for the proper formation of bone
    structures and teeth.

86
Nutrional Deficiencies
  • Nutrional deficiencies diseases in children often
    result from a lack of protein

Kwashiorkor is a specific wasting away often
occurring in infants at weaning. It results from
a lack of protein in the diet
Marasmus is a wasting away of the body tissues
from the lack of calories as well as protein in
the diet. The child is fretful rather than
apathetic and is skinny rather than swollen with
edema.
Kwashiorkor
Marasmus
87
The Ugly Face of Hidden Hunger
Iron Deficiency
Zinc Deficiency
Ca Deficiency Rickets
Vitamin A Deficiency
Iodine Deficiency
88
Global Micronutrient Deficiencies

gt 3 billion people afflicted
(Map from USAID)
89
Prevalence of Vitamin A Deficiency
gt 200 million children affected
Map from WHO
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