Digestive System Notes

1. Digestive System Notes Nutrition

2. Review Most of a tooth is made up of what? dentin Where are nerves and blood vessels located in a tooth? the pulp cavity What is the bacteria that sticks to teeth to cause cavities? plaque The mouth, pharynx, and esophagus make up what? the oral cavity

3. What are the 3 components of saliva and what do they do? Salivary amylase: digests starch Lysozyme: antibacterial action Mucin: lubricant What is a bolus? Combination of food and saliva What does the epiglottis do? Closes over the trachea to prevent food from entering the windpipe

4. What is the common area for food and air? pharynx What is the tube that transfers the bolus from the pharynx to the stomach? What is the muscle movement that does this? esophagus – peristalsis What does the bolus become when it reaches the stomach? chyme Name the 3 parts that make up the small intestine. duodenum, jejunum, ileum

5. What are two of the main functions of the liver? blood filtration – secretes bile What do pancreatic enzymes digest? all classes of foods What happens in the large intestine? chyme is converted to feces – water & salts are absorbed – E.coli synthesizes vitamin K What are the parts of the large intestine? ascending colon, transverse colon, descending colon, sigmoid colon

6. Interesting Nutrition Facts Fast food restaurants use yellow, red, and orange because those are the colors that stimulate hunger.

7. How long can the average person live without food? About 1 month How long can the average person live without water? Less than a week

8. NOTES – NUTRITION • Calorie • the amount of energy needed to raise 1 gram of water 1 degree Celsius • a measure of the energy contained in food • Basic Aspects of Nutrients • MACRONUTRIENTS • needed in large amounts • 4 Types • carbohydrates – fats – proteins - water

9. 1. CARBOHYDRATES • Function: provide energy • 2 basic types • sugars & starch • Sugars • monosaccharides • simple sugars – EX: glucose, fructose, galactose • chemical formula: C6H12O6

10. disaccharides • 2 simple sugars – EX: sucrose (table sugar) • lactose (milk sugar)

11. Starch • complex carbohydrates – long chains of sugar molecules • EX: tortillas, cereal, bread, pasta, potato, rice

12. 2. FATS (lipids) • Functions: • helps the liver make cholesterol (used for cell membranes, myelin, estrogen, testosterone, vitamin D, bile, skin oils) • helps absorb vitamins A, D, E, and K • energy source • insulation • cushions organs

13. 2 types of lipids • saturated fat – beef, lamb, pork, butter, milk, lard, cheese • risk for CHD – does not allow the liver to eliminate LDL cholesterol that clogs arteries • CHD = Coronary Heart Disease • LDL = Low Density Lipoproteins

14. unsaturated fat – from plants, nuts, seeds, fish, avocados, olives, tuna, salmon, olive & canola oil • considered the “good” fat – no LDL cholesterol

15. “Trans” fats • aka: hydrogenated or partially hydrogenated oils • sources: margarine, cookies, crackers, junk food • used to make margarine easy to spread, resists spoilage, cheap to produce • raises LDL (bad) cholesterol & lowers HDL (good) cholesterol levels – nutritionally very bad for you • HDL = High Density Lipoprotein

16. 3. PROTEIN • Functions: • build & repair body tissue, help formation of enzymes, hormones, antibodies • can also be used as an energy source • made of AMINO ACIDS – 20 total • 8 essential – must be obtained from food • 12 non-essential – can be made by the body • functions as a solvent and transport system 4. WATER

17. MICRONUTRIENTS • needed in small amounts • VITAMINS • Functions: • essential for health and growth • water soluble vitamins: B & C • fat soluble vitamins: A, D, E, K Notice what’s missing??? There’s no McDonald’s, Burger King, Hot Cheetos, etc. – NO JUNK FOOD!!!!!

18. MINERALS • Functions: • many functions – helps nerves and muscles function • 7 main minerals: calcium, phosphorus, magnesium, potassium, sulfur, sodium, chloride