Digestive System and Nutrition Digestive System and Nutrition Organs Organs Process of Digestion Process of Digestion Nutrition Nutrition
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Digestive System and NutritionDigestive System and Nutrition
OrgansOrgansProcess of DigestionProcess of Digestion
NutritionNutrition
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Path of Food through the Digestive SystemPath of Food through the Digestive System
mouthpharynx
esophagus
stomach
small
intestinelarge
intestine
anal canal
Produces
peptidases,
maltase,
lactase
Produces
pepsin, HCl
Peristalsis: Muscular contractions that move food through the digestive systemPeristalsis: Muscular contractions that move food through the digestive system
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Accessory Organs and Glands Accessory Organs and Glands
salivary
glands
liver
pancreasgallbladder
Produce
salivaryamylase Produces
pancreatic
amylase,
trypsin,
lipaseProduces
bile
Stores bile
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Process of Digestion and AbsorptionProcess of Digestion and Absorption MouthMouth
± ±Teeth chew foodTeeth chew food
into smaller piecesinto smaller pieces
± ±Salivary amylaseSalivary amylase
(enzyme in saliva)(enzyme in saliva)begins starchbegins starch
digestiondigestion
± ±Tongue mixes foodTongue mixes foodwith saliva to formwith saliva to form
bolus to bebolus to be
swallowedswallowed
Starch in bun has
been broken into
smaller chains of
sugars
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Process of Digestion and AbsorptionProcess of Digestion and Absorption
StomachStomach ± ±HCl acid unfoldsHCl acid unfolds
proteinsproteins
± ±Pepsin (enzyme)Pepsin (enzyme)begins proteinbegins protein
digestion, breakingdigestion, breaking
some peptide bondssome peptide bonds
Protein in beef has
been broken into
smaller chains of
amino acids
gastric pit
gastric gland
esophagus
sphincter
pyloric
sphincter
cells that
secrete
gastric
juice
muscularis
layer has
three layers
of muscle
mucosa layer
has rugae
Contains pepsin,
HCl, mucus
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Process of Digestion and AbsorptionProcess of Digestion and Absorption
Small IntestineSmall Intestine
± ± Large surface area dueLarge surface area due
to numerous villito numerous villi
± ± Bile emulsifies lipidsBile emulsifies lipids
± ± Pancreatic and intestinalPancreatic and intestinalenzymes digestenzymes digest
car bohydrates, lipids,car bohydrates, lipids,
proteinsproteins
± ± Amino acids and sugars Amino acids and sugarsabsor bed into bloodabsor bed into blood
± ± Lipids absor bed intoLipids absor bed into
lymphatic systemlymphatic system
Car bohydrate,
Protein and Fat
have been digestedand absor bed
lacteal
venule
arteriole
villus
lymphatic
vessel
blood
capillaries
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Digestion occurs by Hydrolysis of MacromoleculesDigestion occurs by Hydrolysis of Macromolecules
carbohydrate
pancreatic amylase
maltase
glucose
pH = basic pH = basicpH = basic
protein
trypsin
peptides
lipasepeptidase
amino acids
blood capillaryblood capillary
bile salts fat globules
Carbohydrate digestionCarbohydrate digestion Protein digestionProtein digestion Fat digestionFat digestion
+
emulsification
droplets
cell of
intestinal
villus
lymphatic
capillary
Hydrolysis:
chemical
separation of
subunitshydrolysis
Hydrolysis
Emulsification: physical
dispersion of lipids into
smaller droplets
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Process of Digestion and AbsorptionProcess of Digestion and Absorption
Large IntestineLarge Intestine
± ± Absor bs water Absor bs water
± ± Absor bs salts (minerals) Absor bs salts (minerals)
± ± Ab
sor b
s some vitamins Ab
sor b
s some vitamins ± ±Stores waste for later Stores waste for later
eliminationelimination
Calcium fromcheese has been
absor bed. Fiber
from tomatoes and
lettuce remains.
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Distribution and Use of NutrientsDistribution and Use of Nutrients
Liver Liver
± ± regulates nutrient entry intoregulates nutrient entry into
bloodblood
± ± detoxifies blooddetoxifies blood
± ± stores iron and fatstores iron and fat--solub
lesolub
levitaminsvitamins
± ± makes plasma proteinsmakes plasma proteins
± ± stores and releases glucosestores and releases glucose
± ± produces urea from amino acidsproduces urea from amino acids ± ± produces bileproduces bile
± ± destroys old red blood cellsdestroys old red blood cells
± ± helps regulate blood cholesterolhelps regulate blood cholesterol
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Applying Your Knowledge Applying Your Knowledge
A. A. Where are fats digested?Where are fats digested?
B.B. Where do proteins unfold?Where do proteins unfold?C.C. Where does starch digestion begin?Where does starch digestion begin?
D.D. Where is water absor bed?Where is water absor bed?
1.1. StomachStomach2.2. MouthMouth
3.3. Large IntestineLarge Intestine
4.4. Small IntestineSmall Intestine
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Nutritional RecommendationsNutritional Recommendations
MacronutrientsMacronutrients
± ± Car bohydrateCar bohydrate
± ± FatFat
± ± ProteinProtein
Water Water
MicronutrientsMicronutrients
± ± VitaminsVitamins ± ± MineralsMinerals
Use fats in small amounts
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Car bohydrates: DietaryCar bohydrates: Dietary
RecommendationsRecommendations 58% of calories from car bohydrates58% of calories from car bohydrates
No more than 10% of calories from simple,No more than 10% of calories from simple,
refined sugarsrefined sugars EmphasizeEmphasize
± ± Complex Car bohydratesComplex Car bohydrates StarchStarch
Fiber (cellulose)Fiber (cellulose)
± ± NaturallyNaturally--occurring simple car bohydratesoccurring simple car bohydrates Fructose from fruitFructose from fruit
Lactose from milkLactose from milk
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Fats: Dietary RecommendationsFats: Dietary Recommendations
<< 30% of calories from fats30% of calories from fats
<< 10% of calories from saturated fats10% of calories from saturated fats
Limit cholesterol to 300 mg/dayLimit cholesterol to 300 mg/day
Avoid ³trans´ fatty acids in partially Avoid ³trans´ fatty acids in partially
hydrogenated productshydrogenated products
EmphasizeEmphasize
± ±Unsaturated fatty acids fromUnsaturated fatty acids fromvegetables,vegetables, fish, legumes,fish, legumes, and nutsand nuts
± ±Oils: monoOils: mono-- or polyunsaturatedor polyunsaturated
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Proteins: DietaryProteins: Dietary
RecommendationsRecommendations 12% of calories from proteins12% of calories from proteins
8 essential amino acids obtained8 essential amino acids obtainedfromfrom
± ±Lean sources of animal proteinLean sources of animal protein
± ±Complementary plant proteinsComplementary plant proteins Beans + GrainsBeans + Grains
Beans + SeedsBeans + Seeds
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VitaminsVitamins
Organic compounds used in metabolicOrganic compounds used in metabolicreactions as coenzymes or reactions as coenzymes or
antioxidantsantioxidants Water Soluble: B vitamins, CWater Soluble: B vitamins, C
Fat Soluble: A, D, E, KFat Soluble: A, D, E, K
Adequate amounts come from a varied Adequate amounts come from a varieddiet that includes vegetables and fruitsdiet that includes vegetables and fruits
May prevent cancer and cardiovascular May prevent cancer and cardiovascular diseasedisease
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MineralsMinerals
Inorganic substances required by theInorganic substances required by thebodybody
Macrominerals needed in largeMacrominerals needed in largeamounts, eg. calciumamounts, eg. calcium
Microminerals needed in smaller Microminerals needed in smaller
amounts, eg. ironamounts, eg. iron May need to emphasize certain foodsMay need to emphasize certain foods
to obtain iron or calciumto obtain iron or calcium
May need to limit foods high in sodiumMay need to limit foods high in sodium
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Applying Your Knowledge Applying Your Knowledge
A. A. Which one is a mineral?Which one is a mineral?
B.B. Which macronutrient should supply theWhich macronutrient should supply thegreatest number of calories in the diet?greatest number of calories in the diet?
C.C. Which one may protect against cancer?Which one may protect against cancer?
1.1. CalciumCalcium
2.2. Vitamin CVitamin C
3.3. LipidLipid
4.4. Car bohydrateCar bohydrate
5.5. ProteinProtein
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Reading aReading a
Nutrition LabelNutrition Label
More info atMore info at
http://www.fda.govhttp://www.fda.gov
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Calorie Percentage CalculationsCalorie Percentage Calculations
5 x 4/250 = 0.080 x 100 = 8.0%5 x 4/250 = 0.080 x 100 = 8.0%
5 x 4/250 = 0.080 x 100 = 8.0%5 x 4/250 = 0.080 x 100 = 8.0%
31 x 4/250 = 0.496 x 100 = 49.6%31 x 4/250 = 0.496 x 100 = 49.6%
12 x 9/250 = 0.432 x 100 = 43.2%12 x 9/250 = 0.432 x 100 = 43.2%
3 x 9/250 = 0.108 x 100 = 10.8%3 x 9/250 = 0.108 x 100 = 10.8%
Number of grams
Caloric value
Total calories
T h e s e s h o u
l d a d d t o 1 0
0 % .