Module 2: The Food Supply & Human Digestion & Absorption

  1. describe basic food shopping, preparation, storage, and cooking techniques you can use to decrease the risk of food-borne contamination
    • Select & purchase foods carefully
    • Don't use foods from damaged cans
    • Get frozen/refrigerated foods last at grocery store
    • Promptly freeze/refrigerate groceries once purchased
    • Read dates on food items
    • Avoid unsafe water & food
    • Don't eat raw/undercooked meats
    • Drink only milk & juice that have been pasteurized
    • Avoid soft cheeses
    • Use only purified water for drinking/cooking Practice good personal hygiene
    • Wash hands with soap & hot water for 20 sec
    • Cover cuts & bandages
    • Avoid preparing foods when sick with diarrhea.
    • Keep a clean Kitchen
    • Prevent cross-contamination, wash equipment well between use
    • Replace sponges/towels frequently
    • Handle food safely
    • Wash fruit/vegetables before use
    • Discard moldy foods
    • Be aware how long food has been in your fridge. Store raw meats/poultry below other foods.   
    • Keep Food out of the Temp. Danger Zone & Cook Appropriately
    • Never thaw foods on the counter.
    • Use refrigerator thermometer
    • Marinate foods in the fridge.
    • Cook foods to a safe internal temperature.
  2. Explain how the human body is organized by systems
    The human body is organized by organ systems, when several organs work together to perform a specific function.

    11 major organ systems:

    • Nervous
    • Endocrine
    • Respiratory
    • Digestive
    • Skeletal
    • Cardiovascular
    • Lymphatic & Immune
    • Urinary,
    • Muscular
    • Integumentary (skin, hair, nails)
    • Reproductive.
  3. What organs (10) make up the Digestive System?
    GI Tract (mouth, esophagus, stomach, small intestines, large intestine, rectum & anus), liver, pancreas, and gallbladder.
  4. What are the organs(7) in the GI Tract?
    mouth, esophagus, stomach, small intestines, large intestine, rectum & anus
  5. What is the function of the Mouth & Salivary Glands?
    • Chew food
    • Perceive taste
    • Moisten food with saliva
    • lubricate food with mucus
    • release starch-digesting (amylase) enzyme
    • initiate swallowing reflex
  6. What is the function of the Esophagus?
    • lubricate with mucus
    • move food to stomach by peristaltic waves (swallowing)
  7. What is the function of the Stomach?
    • Store, mix, dissolve, and continue digestion of food
    • Dissolve food particles with secretions
    • Kill microorganisms with acid.
    • Release protein-digesting (pepsin) enzyme
    • Lubricate and protect stomach surface with mucus regulate emptying of dissolved food into small intestine.
    • Produce intrinsic factor for vitamin B-12 absorption.
  8. What is the function of the Liver?
    Produce bile to aid fat digestion and absorption
  9. What is the function of the Gallbladder?
    Store, concentrate and later release bile into the small intestine
  10. What is the function of the Pancreas?
    Secrete sodium bicarbonate and enzymes for digesting carbohydrate, fat and protein.
  11. What is the function of the Small Intestine?
    • Mix and propel contents.
    • Lubricate with mucus.
    • Digest and absorb most substances using enzymes made by the pancreas and small intestine
  12. What is the function of the Large Intestine?
    • Mix & propel contents.
    • Absorb sodium, potassium and water.
    • House bacteria.
    • Lubricate with mucus.
    • Synthesize some vitamins and short-chain fatty acids
    • Form feces.
  13. What is the function of the Rectum?
    Hold feces and expel via the anus, which is the opening to the outside of the body.
  14. Identify the key enzymes and hormones involved in digestion and absorption and their functions
    • Saliva  
    • Mucus 
    • Enzymes 
    • Acid (HCl) 
    • Bile 
    • Bicarbonate 
    • Hormones -
  15. What is the function of Saliva?
    Found in the mouth function: contributes to starch digestion, lubrication, swallowing
  16. What is the function of Mucus?
    Protects GI tract cells, lubricates digesting food;

    found in the mouth, stomach, small & large intestines function:
  17. What is the function of enzymes?
    Found in the mouth(amylase), stomach(pepsin), small intestine, pancreas (carbohydate, fat & protein)

    • amylase - found in the mouth and pancreas to digest starch
    • lipases- digest fats
    • proteases - digest proteins
  18. What is the function of HCl?
    Promotes digestion of protein destroys

    Found in the stomach
  19. What is the function of Bile?
    found in the liver aids in fat digestion (emulsifies fat)
  20. What is the function of Bicarbonate?
    found in the pancreas, small intestine neutralizes stomach acid when it reaches small intestine
  21. What are the Hormones that aid in digestion & Absorption?

    Where can they be found & there functions.
    Found in the stomach, small intestine, pancreas to regulate digestion and absorption.

    • Gastrin - release by the stomach & duodenum in response to food reaching the stomach. triggers the stomach to release HCl and pepsinogen; stimulates gastric and intestinal motility. 
    • Cholecystokinin (CCK)- released by small intestine in response to dietary fat in chyme. stimulates release of pancratic enzymes and bile from the gallbladder.
    • Secretin - released by the small intestine in response to acidic chyme; again by the small intestine as digestion progresses. stimulates release of pancreatic bicarbonate.
    • Motilin - released by the small intestine in response to gastric distension and dietary fat. regulates motility of the GI tract
    • Gastric Inhibitory Peptide - released by Ileum & large intestine in response to fat in the large intestine. signals the stomach to limit the release of gastric juices and slows gastric motility.
    • Peptide YY - released by the Ileum and large intestine in response to fat in the large intestine. inhibits gastric and pancreatic secretions
    • Somatostatin - released by the stomach, small intestine, and pancreas inhibits release of GI hormones; shows gastric emptying, GI motility, and blood flow to the intestine.
  22. Organic
    Food grown with farming practices such as biological pest management, composting, manure application and crop and without the use of synthetic pesticides, fertilizers, antibiotics, sewage sludge, genetic engineering, irradiation and hormones.
  23. Neurotransmitter
    Compound made by a nerve cell that allows for communication between it and other cells
  24. Hormone
    Chemical substance prodced in the body that controls or regulates the activeity of certain cells or organs.  Hormones can be amino acid like (epinephrine), proteinlike (insulin) or fatlike (estrogen).
  25. What are Digestive enzymes?  Identify each, and where they are secreted & what they act upon.
    compounds that aid in the breakdown of carbohydrates, fats and proteins;

    • Enzymes - found in the mouth(amylase), stomach(pepsin), small intestine, pancreas (carbohydate, fat & protein)
    • amylase - found in the mouth and pancreas to digest starch
    • lipases- digest fats
    • proteases - digest proteins
  26. Irradiation
    Process in which radiation is applied to foods, creating compounds (free radicals) within the food that destroy microorganisms that can lead to food spoilage.  This process does not make the food radioactive.
  27. Food-borne illness; list 6 examples and typical food sources
    sickness caused by the ingestion of food containing pathogenic microorganisms and/or their toxins.

    • Examples
    • Ecoli - undercooked ground beef, produce, unpasteurized juices.
    • Staphylococcus aureus - ham, poultry, egg salad, cream filled pastries
    • Shigella - fecal/oral transmission
    • Salmonella - raw and undercooked meats, poultry, eggs and fish, raw sprouts
    • Listeria - unpasteurized mil & soft cheeses, raw meat
    • Clostridium Botulinum - incorrectly home canned vegetables, meats, and fish. incorrectly canned commercial foods.
  28. GRAS List
    Generally Recognized as Safe - prior sanctioned substances are additives approved by the FDA and USDA as being safe or use prior to 1958; these additives have extensive history of safe use in foods.
  29. Food additives; list 6 examples
    substance added to foods to produce a desired effect, such as preservation or nutritional fortification. Over 3000 food additives are regulated by the FDA.

    • Examples:
    • Sorbic acid - antimicrobial agent sulfites - prevents light colored foods from discoloring
    • sodium nitrate/nitrite - curing agents
    • Ascorbic Acid - add tartness in flavor
    • Aspartame - artificial sweetner
    • MSG - flavor enhancer
  30. Prebiotic
    Biosubstance that stimulated bacterial growth in the large intestine
  31. Probiotic
    Live microorganisms that when ingested in adequate amounts can offer a health benefit on the host. 

    ie. - yogurt, fermented foods, miso
  32. Celiac Disease
    Immune mediated disorder that affects primarily the GI tract. It is caused by a physiological response to a protein called gluten.  These proteins damage the villi of the small intestine, causing the villi to flatten.  Damage to the villi results in the malabsorption of nutrients.
  33. Which types of foods are most likely to be involved in food-borne illness?

    Why are they magnets for contamination?
    Meat, poultry, eggs, fish, shellfish, dairy products & fresh produce.

    Because these food provide a good medium for moisture, nutrients and warmth for bacteria to grow when in the temperature danger zone
  34. What is the Delaney Clause?
    The Delaney Clause is a part of the 1958 Food Additives Amendment (section 409) to the 1954 Federal Food, Drug and Cosmetic Act (FFDCA).  It establishes that no residues from pesticides found to cause cancer in animals will be allowed as a food additive.
  35. Which federal agency oversees the safety of meats sold in the United States?
  36. Describe four recommendations for reducing the risk of toxicity from environmental contaminants.
    • Prevent lead poisoning by removing lead from the environment (ie. lead based paints).
    • Polychlorinated Biphenyles - Eat a variety of fish and moderation when local sources of fish have potential for contamination.
    • Mercury - limit the intake of fish to 12 oz/week or no more than 2 meals a week.
    • Pesticides - eat organic foods to limit exposure to pesticides.
  37. Who is particularly susceptible to severe illness from food-borne pathogens?
    Infants, children, the elderly, people with certain diseases, pregnant women and those who have weakened immune systems.
  38. What are the 3 sections of the small intestine?
    • Duodenum
    • Jejunum
    • Ileum
  39. Where is bile synthesized and what is its function?
    Bile is synthesized in the liver.  Bile breaks down the large fat globules into tiny fat droplets (micelles) that are suspended in the watery chyme.
  40. What is the role of the pancreas in digestion?
    The pancreas produces pancreatic juice.  The juice is an alkaline (basic) mixture of sodium bicarbonate (NaHCO2) & enzymes.  The NaHCO2 neutralizes that acidic chyme arriving from the stomach, protecting that small intestine from damage by acid.  Pancreatic enzymes break large macronutrient molecules into smaller subunits.
  41. Which type of absorption requires energy?
    Active absorption - also known as active transport, it allows the cell to concentrate nutrients on either side of the cell membrane.  Amino acids and some sugars, such as glucose, are actively absorbed.
Card Set
Module 2: The Food Supply & Human Digestion & Absorption
Module #2