Digestive & urinary systems & nutrition course notes
April 19, 2012Digestive System
April 19, 2012 Digestion Basics1. Mouth: Saliva has an enzyme that begins to break down starch (bolus)2. Esophagus: Muscular tube3. Stomach: Acids and enzymes digest food further (chyme)4. Small intestine: Enzymes produced here and by the pancreas break down food further and nutrient molecules are absorbed into the blood across the walls of the small intestine. 20 in length: duodenum, jejunum, ileum
April 19, 20125. Large Intestine: Unabsorbed foodmoves into here and water is removedand some vitamins from undigested food.6. Rectum: Waste is expelled from thebody.
April 19, 2012* Nutrition is the study of... - Food and how the body uses food - How and why we make food choices - Nutrients foods contain* What are benefits of good nutrition?
April 19, 2012* 6 Classes of Nutrients - Carbohydrates - Fat - Protein - Vitamins - Minerals - Water
April 19, 2012 Carbohydrates* Provide 4 cal/g (with 1 exception)* Include: - sugars = "simple" - starches = "complex" - fiber (The weird carb, has 0 calories)
April 19, 2012*What happens when you consumecarbohydrates? 1. Breaks down into glucose 2. If blood glucose too high, pancreas reacts and excess is stored in liver and muscles as glycogen 3. When glycogen stores are full, it converts to fat
April 19, 2012 Two Types of Fiber (the weird carb)1. Soluble - Dissolves in water - Cholesterol2. Insoluble - Does not dissolve in water - Solid waste
April 19, 2012 Fat* Provide 9 cal/g* When too much in blood, its stored as triglycerides (3 fatty acids + 1 glycerol) in the fat cells* 2 Types of fat - Saturated: * Usually solid at room temperature * Derived from animal foods - Unsaturated: * Usually liquid at room temperature * Derived from plants
April 19, 2012 Cholesterol (assoc. with saturated fat)* Made by the body and obtained through animal foods* 2 Types: - LDL (bad): Can cause plaque formation in blood vessels - HDL (healthy): Carries cholesterol to liver to be removed from blood
April 19, 2012 Protein* Provides 4 cal/g* Protein builds, repairs, and maintains body tissues* Protein is found in: - Muscles - Bones - Blood - Hormones* Amino acids = the building blocks that make up protein - Nonessential amino acids: produced by body (11) - Essential amino acids: must obtain through diet (9)
April 19, 2012 2 Types of ProteinComplete Protein Incomplete ProteinFrom animal sources From plant sourcesContain all essential Do not contain allamino acids essential amino acidsEx: Meat, fish, Ex: Nuts, seeds,chicken, turkey, milk, beansyogurt, eggs
April 19, 2012 The Vegan Diet* Vegan = Person whose diet does not include foods derived from animals.* How do they get complete protein?* Protein Loading = Eating strategy in which extra protein is eaten to increase muscle size.* Extra protein does not increase muscle size. Resistance exercise increases muscle size. If eat more protein than body needs, its stored as fat.
April 19, 2012U.S. RDA for protein = .36 g x body weightweight (lbs) protein RDA (g)100 36120 43140 50160 58 (Milk carton = 8 g)
April 19, 2012 Vitamins* Provide 0 cal/g* Fat soluble vitamins (A, D, E, & K) can be stored in the body - Toxic if overdose on dietary supplements containing FSV (Hypervitaminosis)* Water soluble vitamins (B & C) cannot be store in the body in significant amounts - Not toxic because can excrete excess WSV
April 19, 2012 Minerals* Provide 0 cal/g* Make up 5% body weight* Macrominerals: Found in body in amounts >5g - Electrolytes: Sodium, Potassium, Chlorine* Trace Minerals: Found in body in amounts <5g
April 19, 2012 Water* Provide 0 cal/g* Consume 8+ glasses/day (and 2 glasses/lb lost after exercise)* Makes up ~60% of our bodies* Lost through: - Urine and solid waste - Breathing - Skin* Dehydration = Water consumed is less than body uses