Digestive System and Nutrition Organs Process of Digestion Nutrition.
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Transcript of Digestive System and Nutrition Organs Process of Digestion Nutrition.
Digestive System and NutritionDigestive System and Nutrition
OrgansOrgansProcess of DigestionProcess of Digestion
NutritionNutrition
Path of Food through the Digestive SystemPath of Food through the Digestive System
mouth
pharynx
esophagus
stomach
small intestine
large 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
Accessory Organs and Glands Accessory Organs and Glands
salivary glands
liver
pancreasgallbladder
Produce salivary amylase Produces
pancreatic amylase, trypsin, lipaseProduces
bile
Stores bile
Process of Digestion and AbsorptionProcess of Digestion and Absorption• MouthMouth
– Teeth chew food Teeth chew food into smaller piecesinto smaller pieces
– Salivary amylase Salivary amylase (enzyme in saliva) (enzyme in saliva) begins starch begins starch digestiondigestion
– Tongue mixes food Tongue mixes food with saliva to form with saliva to form bolus to be bolus to be swallowedswallowed
Starch in bun has been broken into smaller chains of
sugars
Process of Digestion and AbsorptionProcess of Digestion and Absorption
• StomachStomach– HCl acid unfolds HCl acid unfolds
proteinsproteins
– Pepsin (enzyme) Pepsin (enzyme) begins protein begins protein digestion, breaking digestion, breaking some peptide bondssome peptide bonds
Protein in beef has been broken into smaller chains of
amino acids
gastric pit
gastric gland
esophagus
sphincter
pyloricsphincter
cells thatsecretegastricjuice
muscularis layer has three layersof muscle
mucosa layerhas rugae
Contains pepsin, HCl, mucus
Process of Digestion and AbsorptionProcess of Digestion and Absorption• Small IntestineSmall Intestine
– Large surface area due Large surface area due to numerous villito numerous villi
– Bile emulsifies lipidsBile emulsifies lipids– Pancreatic and intestinal Pancreatic and intestinal
enzymes digest enzymes digest carbohydrates, lipids, carbohydrates, lipids, proteinsproteins
– Amino acids and sugars Amino acids and sugars absorbed into bloodabsorbed into blood
– Lipids absorbed into Lipids absorbed into lymphatic systemlymphatic system
Carbohydrate, Protein and Fat
have been digested and absorbed
lacteal
venule
arteriole
villus
lymphaticvessel
bloodcapillaries
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
+
emulsificationdroplets
cell ofintestinalvillus
lymphaticcapillary
Hydrolysis:chemical
separation of subunits
hydrolysisHydrolysis
Emulsification: physical dispersion of lipids into
smaller droplets
Process of Digestion and AbsorptionProcess of Digestion and Absorption
• Large IntestineLarge Intestine– Absorbs water Absorbs water
– Absorbs salts (minerals)Absorbs salts (minerals)
– Absorbs some vitaminsAbsorbs some vitamins
– Stores waste for later Stores waste for later eliminationelimination
Calcium from cheese has been absorbed. Fiber
from tomatoes and lettuce remains.
Distribution and Use of NutrientsDistribution and Use of Nutrients• LiverLiver
– regulates nutrient entry into regulates nutrient entry into blood blood
– detoxifies blooddetoxifies blood
– stores iron and fat-soluble stores iron and fat-soluble vitaminsvitamins
– 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
Applying Your KnowledgeApplying 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 absorbed? Where is water absorbed?
1.1. StomachStomach
2.2. MouthMouth
3.3. Large IntestineLarge Intestine
4.4. Small IntestineSmall Intestine
Nutritional RecommendationsNutritional Recommendations
• MacronutrientsMacronutrients– CarbohydrateCarbohydrate– FatFat– ProteinProtein
• WaterWater• MicronutrientsMicronutrients
– VitaminsVitamins– MineralsMinerals
MIL
K
FR
UIT
S
GR
AIN
S
ME
AT
& B
EA
NS
VE
GE
TA
BL
ES
Use fats in small amounts
June 2011 RecommendationsJune 2011 Recommendations
Balancing CaloriesBalancing Calories• Enjoy your food, but eat less. Enjoy your food, but eat less. • Avoid oversized portions. Avoid oversized portions. Foods to IncreaseFoods to Increase • Make half your plate fruits and Make half your plate fruits and vegetables. vegetables. • Make at least half your grainsMake at least half your grains whole grains. whole grains. • Switch to fat-free or low-fat Switch to fat-free or low-fat (1%) milk. (1%) milk. Foods to ReduceFoods to Reduce• Compare sodium in foods likeCompare sodium in foods like soup, bread, and frozen meals, soup, bread, and frozen meals,
and choose the foods with and choose the foods with lower numbers. lower numbers. • Drink water instead of sugary Drink water instead of sugary drinks. drinks.
Carbohydrates: Dietary Carbohydrates: Dietary Recommendations Recommendations
• 58% of calories from carbohydrates58% of calories from carbohydrates• No more than 10% of calories from simple, No more than 10% of calories from simple,
refined sugars refined sugars • EmphasizeEmphasize
– Complex CarbohydratesComplex Carbohydrates• StarchStarch• Fiber (cellulose)Fiber (cellulose)
– Naturally-occurring simple carbohydratesNaturally-occurring simple carbohydrates• Fructose from fruitFructose from fruit• Lactose from milkLactose from milk
Fats: Dietary Recommendations Fats: Dietary Recommendations
• << 30% of calories from fats 30% of calories from fats
• << 10% of calories from saturated fats 10% of calories from saturated fats
• Limit cholesterol to 300 mg/dayLimit cholesterol to 300 mg/day
• Avoid “trans” fatty acids in partially Avoid “trans” fatty acids in partially hydrogenated productshydrogenated products
• EmphasizeEmphasize
– Unsaturated fatty acids from Unsaturated fatty acids from vegetables,vegetables, fish, legumes,fish, legumes, and nutsand nuts
– Oils: mono- or polyunsaturatedOils: mono- or polyunsaturated
Proteins: Dietary Proteins: Dietary Recommendations Recommendations
• 12% of calories from proteins12% of calories from proteins
• 8 essential amino acids obtained 8 essential amino acids obtained from from
–Lean sources of animal proteinLean sources of animal protein
–Complementary plant proteinsComplementary plant proteins• Beans + GrainsBeans + Grains
• Beans + SeedsBeans + Seeds
Vitamins Vitamins
• Organic compounds used in metabolic Organic compounds used in metabolic reactions 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 varied
diet that includes vegetables and fruits diet that includes vegetables and fruits • May prevent cancer and cardiovascular May prevent cancer and cardiovascular
diseasedisease
Minerals Minerals
• Inorganic substances required by the Inorganic substances required by the bodybody
• Macrominerals needed in large Macrominerals needed in large amounts, eg. calciumamounts, eg. calcium
• Microminerals needed in smaller Microminerals needed in smaller amounts, eg. ironamounts, eg. iron
• May need to emphasize certain foods May 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
Applying Your KnowledgeApplying Your Knowledge
A.A. Which one is a mineral? Which one is a mineral?
B.B. Which macronutrient should supply the Which macronutrient should supply the greatest 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. CalciumCalcium2.2. Vitamin CVitamin C3.3. LipidLipid4.4. CarbohydrateCarbohydrate5.5. Protein Protein
Reading a Reading a Nutrition LabelNutrition Label
More info atMore info athttp://www.fda.govhttp://www.fda.gov
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
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