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206 Cards in this Set
- Front
- Back
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What is the definition of 'nutrition'?
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Nutrition is:
the science of food, the nutrients and the substances therein, their action, interaction, and balance in relation to health and disease, and the process by which the organism ingests, digests, absorbs, transports, utilizes, and excretes food substances |
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Where do nutrients come from?
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Nutrients come from food
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What do nutrients do?
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Nutrients:
1.) Provide energy 2.) Provide building blocks 3.) Maintain body cells 4.) Are essential |
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What are the 2 main factors that account for chronic disease?
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1.) Poor diet and 2.) sedentary lifestyle are risk factors for chronic diseases, accounting for ~2/3 of all deaths
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What health condition accounts for 29% of all deaths?
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Disease of the heart (29% of all deaths)
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What health condition accounts for 22% of all deaths?
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Cancer (22%)
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What health condition accounts for 7% of all deaths?
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Cerebrovascular disease (7%)
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What health condition accounts for 3% of all deaths?
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Diabetes (3%)
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What are some notable examples of nutrition history?
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-Iron used to treat anemia
-Citrus fruits used to treat scurvy -Carbon-containing compounds provide energy -Protein needed for survival -Identification of classes of nutrients -Thiamin and beriberi -Atwater numbers -Essential amino acids -Recommended Dietary Allowances -Intravenous feeding |
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Name the six classes and sources of nutrients
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-Carbohydrates
-Fats -Proteins -Vitamins -Minerals -Water |
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What are carbohydrates?
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-Composed of C, H, O
-Provide a major source of fuel for the body -Basic unit is glucose -Simple and Complex CHO -Energy yielding (4 kcal /g) |
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What are lipids?
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-Composed of C, H and few O
-Basic unit is fatty acid -Triglyceride is the major form of lipid -Fats and oils -Monounsaturated Fatty Acids >Polyunsaturated Fatty Acids >Saturated Fatty Acids >Essential Fatty Acids >Energy yielding (9 kcal /g) |
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What are proteins?
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-Composed of C, O, H, N
-Basic unit is amino acid -Make up bones, muscles, other tissues -(9) Essential amino acids -(11) Nonessential amino acids -Energy yielding (4 kcal /g) |
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Name three amino acids that compose proteins.
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Alanine, valine, and methionine
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What are vitamins?
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-Composed of various elements
-Vital to life -Needed in tiny amounts -Cooking loss -Fat soluble -Water soluble -Yields no energy |
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What are minerals?
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-Inorganic substances
-Needed in tiny amounts -Not destroyed in cooking -Trace minerals -Major minerals -Yields no energy |
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Describe the components of water.
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-Composed of H, O
-Vital to life -Is a solvent, lubricant, medium for transport, chemical processes, and temperature regulator -Makes up majority of our body -Yields no energy |
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How many nutrients do protein, fat, and carbohydrates provide?
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~ 500 g/d
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How many nutrients do minerals provide?
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~ 20 g/d
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How many nutrients to vitamins provide?
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< 300 mg/d
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What is the energy (from food) used for?
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-Build new compounds
-Perform muscular movements -Promote nerve transmissions -Maintain ion balance |
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Define a calorie.
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“the amount of heat it takes to raise the temperature of 1 gram of water by 1 degree Celsius”
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How is food measured?
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Food is measured in kilocalories
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true or false:
The "calories" on a nutrition label are in kcals |
true!
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How much energy does a carbohydrate yield?
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carbohydrate: 4 kcal/gram
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How much energy does protein yield?
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Protein: 4 kcal/gram
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How much energy does fat yield?
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Fat: 9 kcal/gram
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How much energy does alcohol yield?
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Alcohol: 7 kcal/gram
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true or false:
Energy yielding nutrients can be adjusted for digestibility. |
true!
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For the typical American diet, what % of kcals come from proteins?
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Typical American Diet:
protein --> 16% kcals |
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In the typical American diet, what % of kcals come from carbohydrates?
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Typical American Diet:
carbohydrates --> 50% kcals |
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In the typical American diet, what % of kcals come from fats?
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Typical American Diet:
fat --> 33% kcals |
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What % of protein comes from animal sources?
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~66% of protein comes from animal sources
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What % of sugar comes from simple sugars?
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~50% from simple sugars
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What % of fats from animals sources?
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~60 % from animal fats
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How do you assess the current diet?
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**Surveys**:
1.)Continuing Survey or Food Intake by Individuals (CSFII) 2.) National Health and Nutrition Examination Survey (NHANES) **Make Conclusions** -Lacking nutrients -Energy balance -Sodium intake -Fruit and vegetable intake |
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How can we improve our diets?
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-Lower intake of saturated fats, trans
fats, sugars, and cholesterol intake -Include a variety of foods -Not to overindulge -Active lifestyle -Use supplements wisely -Use meal replacement bars wisely |
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What are some guidelines for the "Healthy People 2010"?
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-To promote healthy lifestyle and reduce
preventable death and disease -Increase the number of healthy people -Reduce obesity in adults and children -Increase intake of fruits, vegetables, and whole grain products -Lower the intake of fat, saturated fats, and sodium -Increase the intake of calcium and iron |
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How can we use scientific research
to determine nutrient needs? |
-Ask questions
-Generate hypotheses -Experiments -Reject incorrect explanations -Form model -Publication and peer review -Follow-up studies |
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What are the 2 main Scientific Methods used?
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1.) **Epidemiology**
-Prospective, cohort studies -Retrospective 2.) **Experiments** -Animal studies -Human experiments >>Case-control study >>Double-blind study |
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Does Ca really help with wt. loss? What are the hypothesized mechanisms? What else was determined from the study?
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Hypothesized mechanisms:
-Decreased fat absorption -Calcium/vitamin D balance alters fat breakdown ********************************** -Diet surveys -Retrospective analysis -Animal experiments -Human experiments -Conclusions based on current evidence: balancing intake with physical activity remains the best approach to weight loss; meeting recommended calcium intake may help |
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In research, what tools increase the confidence in the research hypothesis?
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1.) lab animal studies
2.) case control studies 3.) human intervention trials 4.) biologically plausibility for the idea 5.) epidemiological studies 6.) clinical practice observations |
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What is the Scientific Model?
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The Scientific Model:
-Steps in the scientific method -Research purpose or problem -Hypothesis -Experimentation -Interpretation or analysis -Conclusion -Theory formulation |
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Who developed the Scientific Method?
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**Antoine Lavoisier**
-First to implement this method -Hypothesized that respiration in animals was a form of combustion -Experimented to test the hypothesis Theorized that consumption of O2 is related to amount of C burned or heat produced in the animal |
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What are the 2 types of research methodologies?
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1.) Qualitative
>>Uses verbal data 2.) Quantitative >>Uses data expressed in numbers |
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Is a historical methodology qualitative or quantitative?
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Historical methodologies are qualitative.
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Is a descriptive survey method qualitative or quantitative?
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Descriptive survey methods are qualitative.
ex: case studies |
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Are analytical survey methods qualitative or quantitative?
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Analytical survey methods are quantitative
ex: -Statistical methods -Observational research -Epidemiological or cohort studies |
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Are experimental methods qualitative or quantitative?
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Experimental methods are quantitative
ex: -Control group-experimental group -Based on cause & effect -Clinical trial |
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Define validity.
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Validity:
-Whether instrument measures what it’s supposed to measure |
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Define accuracy.
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Accuracy
-How close instrument is to true value |
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Define reliability.
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Reliability
-Whether it’s accurate enough |
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Define precision.
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Precision
-Whether it is consistent in its results |
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How do you initiate research?
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Initiation of Research:
-Select the research topic or problem to be solved -Clearly state the question to be researched -Prepare a research plan/proposal -Plan for the collection & preparation of data |
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What are some problems/pitfalls in research?
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-Failure to plan properly
-Solvable problems -Insolvable problems -Application of statistics in the analysis of data -Insufficient power of the statistical test |
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How do you evaluation research & scientific literature?
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Evaluation of Research and Scientific Lit:
-Type of publication -Peer-reviewed journals -Meta-analysis -Review articles -Nutrition in the media |
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What should a good diet contain?
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A good diet should contain BALANCE and VARIETY.
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Define "variety"
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Variety = choosing different foods
~Not eating the “same old thing” -Choose a number of different foods within any given food group ~Ensures the diet contains sufficient nutrients ~Inclusion of fruits and vegetables to provide phytochemicals |
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Define "balanced"
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Balanced = selecting foods from the 5 different food groups
~Not overconsuming any one food ~Eat foods from the five major food groups |
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Define "moderation"
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Moderation = planning intake and portion control
~Plan your entire day’s intake ~Be aware of portion sizes ~Moderate, not eliminate ~No such thing as a ‘good’ food or ‘bad’ food |
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What is nutrient density?
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Nutrient density:
Comparison of vitamin and mineral content to number of kcals |
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What are empty calories?
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Empty Calories:
Provides kcals and few to no other nutrients |
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What is energy density?
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Energy Density:
Provides kcals and few to no other nutrients |
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What are the 2 main factors that determine 'desirable nutrition'?
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"Desirable Nutrition":
-Adequate liver stores of nutrients -Adequate blood levels of iron-related compounds |
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What are the 2 main factors that describe 'undernutrition'?
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"Undernutrition":
-Reduced biochemical functions -Clinical signs and symptoms |
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What are the 2 main factors that describe "overnutrition"?
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"Overnutrition":
-Obesity -Supplements |
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How can we measure a current nutritional status? (6 ways)
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1.) Background Factors....
-Medical history -List of medications -Social history -Education level -Economic status 2.) Anthropometrics... -Height and weight -Skinfolds -Body circumferences 3.) Biochemical... -Concentrations of nutrients and nutrient by-products in blood, urine, or feces 4.) Clinical... -Physical evidence of diet-related diseases 5.) Dietary 6.) Economic status |
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What are the limitations of nutritional assessments?
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-Long time lapse
-Clinical evidence is not very specific |
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How do studies confirm links between risk for chronic diseases and dietary habits? (examples)
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-Variety
-Fiber-rich foods -Inclusion of fish -Restriction of animal fat and trans -Avoidance of overweight and obesity -Moderate alcohol consumption |
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What are 2 very important health practices?
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1.) Regular activity
2.) not smoking! |
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What is a DRI?
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Daily Reference Intake (DRI):
-New nutrient recommendations -Nutrient recommendations to prevent chronic diseases |
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What is an EAR?
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Estimated Average Requirement (EAR):
-Nutrient intake estimated to meet the needs of 50% of the individuals in a certain age and gender group -Uses a measurable functional marker -Adjusts for digestibility -Used to evaluate the adequacy of diets of a group |
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What is an RDA?
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Recommended Daily Allowance (RDA):
-Nutrient intake that is sufficient to meet the needs of 97 – 98% of individuals in an age and gender group -EAR x 1.2 -Can only be set if EAR is established -Accounts for nutrients’ ability to prevent disease in addition to preventing deficiency |
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What is an Adequate Intake?
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Adequate Intake:
-In the absence of adequate information to establish an RDA, AI is assigned -Based on estimates of intakes that appear to maintain nutrition status in certain populations -Set for some vitamins, choline, some minerals, essential fatty acids, fiber -Set for children under the age of 1 |
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How do we estimate energy requirements?
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Estimating Energy Requirements...
-Average energy needs for various age and gender groups -More conservative than individual nutrient recommendations to promote reduction in overweight and obesity -Maintenance of healthy weight is best guideline |
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What is a Tolerable Upper Intake Level?
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Tolerable Upper Intake Level:
-Maximum level of daily intake unlikely to cause adverse health effects -Chronic daily use -Set to protect even most susceptible individuals -Not a goal, but a ceiling -Not enough information to set UL for all nutrients |
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Name some appropriate uses of DRIs...(4)
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Appropriate Uses of DRI's:
-Diet planning -Aim for RDA or AI -Do not exceed the UL -For the healthy population |
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Are DRIs on food labels?
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DRIs are not used on food label (they're gender- and age- specific)
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What are the 2 Daily Values that the FDA developed?
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1.) Reference Daily Intake (RDI) for vitamins and minerals
2.)Daily Reference Value (DRV) for nutrients without RDAs Only used on food labels |
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What are the Reference Daily Intakes?
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Reference Daily Intakes (RDIs):
-For vitamins and minerals -Based on the 1968 RDAs (highest RDA values) -Planned revision to reflect the latest nutrition standards |
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What are the Daily Reference Values?
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Daily Reference Values (DRVs):
-For dietary components with no RDA or related nutrient standard -Consumers can evaluate own food choice -Not everyone has same desirable standards for intake -Based on 60% of total kcals from carbohydrates, 30% from fat, and 10% from protein |
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What is the "basis" of human physiology?
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The CELL.
cells --> tissues tissues --> organs organs --> organ systems |
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What is "cell turnover"?
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Cell turnover:
-Requires energy, adenosine triphosphate -Requires nutrients |
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Name the 4 types of human tissues.
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1.) Epithelial
2.) Connective 3.) Muscle 4.) Nervous |
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What does epithelial tissue do?
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*Epithelial tissue*:
-Lines body surfaces -Secretes substances -Absorbs nutrients -Excretes waste |
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What does connective tissue do?
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*Connective tissue*:
-Supports and protects body -Stores fat -Produces blood cells |
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What does muscle tissue do?
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*Muscle tissue*:
-Controls movement |
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What does nervous tissue do?
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*Nervous tissue*:
-Controls communication |
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Name the Organ Systems...
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ORGAN SYSTEMS:
-Cardiovascular -Lymphatic -Nervous -Endocrine -Immune -Digestive -Urinary -Integumentary -Skeletal -Muscular -Respiratory -Reproductive |
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Name the Structures of the Digestive Tract & the Digestive Process....
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Main structures:
-Oral cavity -Esophagus -Stomach -Small & large intestines Accessory organs: -Pancreas -Liver -Gallbladder |
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What are the 4 main components of the lumen?
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*Lumen*:
1.) Mucosa 2.) Submucosa 3.) Muscularis externa 4.) Serosa or adventitia |
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What is the mucosa (layer of lumen) made of?
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*Mucosa*:
-Epithelium, lamina propria, muscularis mucosa |
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What is the submucosa (layer of lumen) made of?
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*Submucosa*
-Connective tissue, lymphoid tissue, submucosal plexus |
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What is the muscularis externa (layer of lumen) made of?
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*Muscularis externa*:
-Circular & longitudinal smooth muscle, myenteric plexus |
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What is the serosa or adventitia (layer of lumen) made of?
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*Serosa or adventitia*:
-Connective tissue, visceral peritoneum |
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Describe the gastrointestinal tract
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The gastrointestinal tract stretches from the mouth to anus
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Name the physiological functions of the GI tract (autonomic control)
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GI TRACT:
-Motility -Secretion -Digestion -Absorption -Elimination -Nutrient production |
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What do lysozymes do?
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Lysozymes kill bacteria!
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How does the tongue aid in the digestion of food?
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Tongue:
-Taste receptors -Flavor is enhanced with the olfactory cells -Enzymes to help breakdown fatty acids |
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What are the 3 main components of the oral cavity?
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Oral Cavity:
1.) mouth and pharynx 2.) salivary glands 3.) enzymes in saliva |
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What occurs in the esophagus during the swallowing process?
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Esophagus:
-Moves bolus from oral cavity to stomach -Swallowing -Voluntary, pharyngeal, esophageal -Peristalsis -Gastroesophageal sphincter -Selected diseases & conditions of the esophagus – GER gastroesophageal reflux disease |
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Describe the flow of digestion in the stomach....
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Stomach:
-Lower esophageal sphincter and pyloric sphincter >>Capacity of ~4 cups -Parietal cells secrete hydrochloric acid -Aids protein digestion -Solubilizes minerals for absorption -Chief cells secrete enzymes -Holds food for 2-4 hours -Results in the formation of chyme -Mucus layer prevents autodigestion -Secretion of the intrinsic factor |
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What are the 4 main regions of the stomach?
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Stomach:
1.) Cardia region 2.) Fundus 3.) Body 4.) Antrum or distal pyloric region -Grinds food & mixes with gastric juices to form chyme -Strong peristalsis for gastric emptying |
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What are the main components of the stomach that aid in digestion?
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The Stomach:
-Gastric juice -HCl -Converts pepsinogen to pepsin -Denatures proteins -Releases nutrients from organic complexes -Acts as bacteriocide -Enzymes - pepsin, amylase, lipase -Mucus -Intrinsic factor |
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How does the stomach regulate gastric secretions?
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The stomach regulates gastric secretions via
-Hormones & peptides that inhibit gastric secretions -Hormones & neuropeptides that stimulate gastric secretions -Other factors -HCl release stimulated by gastrin, acetylcholine, histamine |
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What are the main structural components of the SMALL intestine?
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the SMALL intestine:
-Structural aspects of the small intestine -Large circular folds of mucosa -Villi - finger-like projections -Microvilli - hair-like extensions of the cells’ plasma membranes -Brush border -Crypts of Lieberkühn |
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Describe the flow of digestion thru the SMALL intestine~
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SMALL intestine has 3 segments
1.) Duodenum (10 inches) 2.) Jejunum (4 feet) 3.) Ileum (5 feet) -Narrow diameter -Food remains in small intestine 3-10 hours -95% of digestion takes place in small intestine (mostly in duodenum and upper jejunum) |
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Name the 2 main functions of the SMALL intestine.
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the SMALL intestine...
1.) Regulation of intestinal secretions & motility 2.)Immune system protection of the gastrointestinal tract *Mucosa-associated lymphoid tissue (MALT) *Gut-associated lymphoid tissue (GALT) |
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Describe the flow of digestion thru the LARGE intestine~
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the LARGE intestine (aka, the COLON) has 5 segments
-3.5 ft total 1.) Cecum 2.) Ascending colon 3.) Transverse colon 4.) Descending colon 5.) Sigmoid colon **note:** -Very little digestion takes place -Food remains in colon 24-72 hours -Terminates in rectum -Elimination of feces |
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Name the 3 main Accessory Organs.
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1.) Liver: production of bile to aid in fat digestion and absorption
2.) Pancreas: produces enzymes and sodium bicarbonate 3.) Gallbladder: storage of bile |
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Describe the components of the LIVER
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LIVER:
-Consists of lobes made of lobules -Portal circulation -Bile canaliculi |
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Describe the components of the GALLBLADDER
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the GALLBLADDER:
-Bile synthesis -Selected conditions/diseases of the gallbladder -Bile storage -The function of bile -The recirculation & excretion of bile -Bile circulation & hypercholesterolemia |
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Describe the components of the PANCREAS
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the PANCREAS:
-Digestive enzymes produced by acinar exocrine cells -Pancreatic juice contains: -Bicarbonate -Electrolytes -Pancreatic digestive enzymes -Regulation of pancreatic secretions -Pancreatic digestive enzymes |
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How do enzymes impact the digestive process?
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Enzymes:
>Speed digestion by catalyzing chemical rxns >Hydrolysis >Mouth and stomach cells secrete few enzymes >Majority of enzymes are secreted by *pancreas* and *small intestine* -Pancreas releases specific enzymes in response to nutrient content of diet |
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What are the four main hormones that regulate digestion?
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4 Main HORMONES that regulate digestion:
1.) Gastrin 2.) Secretin 3.) Cholecystokinin 4.) Gastric Inhibitory Peptide **note: Hormones have specific site of synthesis, enter bloodstream, and act on remote site by binding to hormone receptors |
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Name the hormone-LIKE compounds that diffuse from cell-to-cell (4 of them).
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Hormone-like compounds:
1.) Vasoactive intestinal peptide 2.) Bombesin 3.) Substance P 4.) Somatostatin |
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Where does gastrin originate?
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Gastrin originates in the pyloric region of the upper duodenum
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How is gastrin secretion stimulated?
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Gastrin is stimulated by food or thoughts of food
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What does gastrin do in the stomach?
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Gastrin stimulates the flow of stomach enymes and HCl
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Where does secretin originate?
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Secretin originates in the duodenum and jejunum
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How is secretin stimulated?
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Secretin is stimulated by the presence of acidic chyme and the presence of peptones in the duodenum
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What does secretin stimulate?
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Secretin stimulates the secretion of bicarbonate (to neutralize!)
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T or F:
Secretin slows gastric-emptying. |
True. Secretin slows gastric-emptying.
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Where does CCK originate?
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CCK originates in the duodenum and jejunum.
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What stimulates the secretion of CCK?
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CCK is stimulated by food, presence of fat and protein in the duodenum.
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What does CCK stimulate? (2 things)
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1.) CCK stimulates the contraction of the gallbladder and the flow of bile
2.) CCK stimlates the release of enzyme-rich pancreatic fluids |
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T or F:
CCK slows gastric emptying. |
True. CCK (and secretin!) slow gastric emptying.
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What does GIP stand for?
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GIP = Gastric Inhibitory Peptide
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Where does GIP originate?
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GIP originates in the duodenum and jejunum
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How is GIP stimulated?
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GP is stimulated by the presence of fat and protein
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What does GIP inhibit?
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GIP inhibits the secretion of stomach acids and enzymes
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T or F:
GIP slows gastric emptying. |
True! GIP (and CCK and secretin) slow gastric emptying.
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Name the regulatory peptides. (8 of them. What are the main 4?
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The 8 Regulatory Peptides: *=main
*1.) GIP *2.) CCK *3.) Secretin *4.) Gastrin 5.) Motilin 6.) Peptide YY 7.) Amyline 8.) Enteroglucagon |
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What are the two main types of regulatory peptides?
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Regulatory Peptides:
1.) Paracrine-Acting Substances 2.) Neurocrine Peptides |
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What are the 3 main paracrine-acting substance?
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Paracrine-acting substances:
1.) Somatostatin 2.) Glucagon-like peptides 3.) Insulin-like growth factors |
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What are the 4 main neurocrine peptides?
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Neurocrine peptides:
1.) Vasoactive intestinal polypeptide (VIP) 2.) Gastrin-releasing peptide (GRP) 3.) Neurotensin 4.) Substance powder (P) |
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What is a sphincter?
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Sphincter: A muscular and circular valve in the GI tract that controls the flow of food stuff
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What does the upper esophageal sphincter do?
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Upper esophageal sphincter:
-controls flow of food into the esophagus |
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What does the lower esophageal (CARDIAC) sphincter do?
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Lower esophageal (CARDIAC) sphincter:
-controls reflux of stomach contents into the esophagus |
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What does the pyloric sphincter do?
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Pyloric sphincter:
-controls movement of stomach contents into the small intestine |
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What does the Sphincter of Oddi do?
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Sphincter of Oddi:
-controls the output of bile and digestive enzymes from the gallbladder and pancreas into the small intestine |
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What does the Ileocecal valve do?
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Ileocecal Valve:
-prevents large intestine contents (bacteria) from backflow into the small intestine |
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What is the difference between peristalsis and segmentation?
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*Peristalsis*: ring of contraction that propels material along the GI tract
*Segmentation*: back&forth action that breaks apart food |
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What is a 'mass movement'?
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Mass Movement:
-peristaltic wave that contracts over a large area of the large intestine to help eliminate waste |
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What are the causes of excess acid and pepsin (--> cause an ulcer)?
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Causes of excess acid and pepsin:
-dietary factors (Ca) -Histamine -certain medical conditions -genetics -smoking |
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What are the causes of a weakened mucosal defense (--> cause an ulcer)?
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Weakened Mucosal Defense:
-smoking -genetics -NSAIDs -H. pylori -dietary factors (alcohol) -stress |
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What gets absorbed in the STOMACH?
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Absorption in the STOMACH:
-water -some alcohol -forms of fat |
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What gets absorbed in the SMALL INTESTINE?
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Absorption in the SM INTESTINE:
*primary site for absorption!* -absorbs 95% of ingested energy from protein, fat, carbohydrates, and alcohol |
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What gets absorbed in the LARGE INTESTINE?
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Absorption in the LG INTESTINE:
-water -minerals -short chain FAs |
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Describe the key components of absorption in the SM intestine:
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Absorption in the SM Intestine:
-The wall is folded -Villi projections are located on the folds -Absorptive cells (enterocytes) are located on the villi -Absorptive cells have brush border made of microvilli covered with glycocalyx -Increases intestinal surface area 600 x |
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What types of absorptive cells are found in the intestinal mucosa?
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Intestinal mucosa:
-absorptive cells -mucosal cells -endocrine cells |
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Where are absorptive cells produced?
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Absorptive cells are produced in crypts.
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What occurs are the absorptive cells move from the crypts to the tips of the villi?
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Migration and maturation occurs as the cells move from the crypts to the tips of the villi
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T or F?:
The tips of the absorptive cells are slough off from digestive enzymes. |
True. Degradation of cells at the tips of the villi by digestive enzymes; they're sloughed off
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How many days does it take the migrating cells to replace the dying cells?
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Its takes <6 days to replace the dying cells
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What do absorptive cells deterioration cause nutrient deficiency?
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Nutrient deficiency is caused by the high turnover of cells
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Name the 4 types of Absorption.
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Absorption:
1.) Passive 2.) Facilitated 3.) Active 4.) Endocytosis |
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What is Passive absorption?
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Passive Absorption:
-intestinal wall is permeable to the nutrient -Going from higher to lower concentration -No energy expended |
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What is Facilitated absorption?
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Facilitated Absorption:
-A carrier shuttles substances into the absorptive cells -Going from higher to lower concentration -No energy expended |
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What is Active absorption?
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Active absorption:
-Uses a carrier and ATP |
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What is Endocytosis absorption?
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Endocytosis absorption:
-Phagocytosis and pinocytosis |
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Where does intestinal villi drain into?
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Intestinal villi drains into portal or lymphatic vessels
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What is portal circulation?
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Portal circulation:
*Water-soluble nutrients: proteins, carbohydrates, medium-chain fatty acids, B vitamins, vitamin C *Portal vein delivers nutrient-rich blood to liver |
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What is lymphatic circulation?
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Lymphatic circulation:
Fat-soluble nutrients: long-chain fatty acids, fat-soluble vitamins *Large particles *Contents of lymphatic system enter circulation at thoracic duct |
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Describe ENTEROHEPATIC circulation.
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Think ENTEROHEPATIC = bile
*Bile circulation -Liver -gallbladder -small intestine -portal vein -liver ***~98% of bile is recycled |
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Where is food absorption completed?
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Absorption is completed in the LG intestine!
But only water, minerals, undigested starches, fiber, and minor amounts of protein, fat, and carbohydrates reach the large intestine |
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What does the LG intestine absorb?
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Large intestine absorbs:
-Water -Sodium -Potassium -Short-chain fatty acids -Vitamin K |
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Where is fat stored?
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Fat us stored in adipose tissue
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T or F:
Short-term storage of carbs are in muscle, liver, and blood. |
True! Short-term storage of carbs is in muscle, liver, and blood.
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Where are vitamins and minerals stored? (organ)
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Vitamins and minerals are stored in the liver
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Where is Ca stored?
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Calcium is stored in bone...duh.
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Where is protein obtained?
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Protein is obtained from muscle tissue.
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What are the primary nutrients absorbed in the stomach?
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Stomach:
-water (minor amnt) -alcohol (20% total) |
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What are the primary nutrients absorbed in the SM intestine?
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SM intestine:
-Ca, Mg, and other minerals -glucose -AAs -fats -vitamins -water (70-90%) -bile acids |
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What are the primary nutrients absorbed in the LG intestine?
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LG intestine:
-Na -K -some FAs -gases -water (up to 10 or 30% of total) |
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What purpose does saliva play in digestion?
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Saliva contributes to starch digestion and aids in lubrication and swallowing
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What purpose does mucus play in digestion?
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Mucus protects and lubricates cells.
~it's found in the mouth, stomach, and SM and LG intestines |
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What purpose do enzymes play in digestion?
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Enzymes {amylases, lipases, proteases} promote digestion of food stuffs into smaller particles
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T or F:
Enzymes are found in the LG intestine. |
False! Enzymes are not found in the LG intestine. Enzymes (such as amylase, lipase, and protease) are found in the mouth, stomach, SM intestine, and pancreas.
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What is the purpose of acid in digestion?
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Acid in the stomach promotes digestion of proteins, among other functions.
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What is the purpose of bile in digestion?
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Bile {produced in the liver and stored in the G. bladder} suspends fat/water like an emulification, and aids in digestion in the SM intestine
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What are some examples of BILE?
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Bile: bile acids, cholesterol, and lecithins
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What is the purpose of bicarbonate in digestion?
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Bicarbonate neutralizes stomach acid when it reaches the SM intestine
-also: bicarbonate is produced in the pancreas and small intestine |
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What is the purpose of hormones (gastrin, secretin, CCK, and gastric-inhibitory peptide) in digestion?
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Hormones stimulate the production +/or release of acid, enzymes, bile, and bicarbonate. They also help regulate peristalsis and GI tract flow.
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Where are digestive hormones? (2 places)
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The STOMACH and SM intestine is the site of hormonal production
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Name the primary function of the mouth.
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Mouth: chew food, some digestion of starch
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Name the primary function of the esophagus.
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Esophagus: passageway for food
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Name the primary function of the stomach.
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Stomach: food storage; acidity kills bacteria! and some digestion of protein
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Name the primary function of the small intestine.
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SM intestine:
-final digestion of NRG-yielding nutrients, and the absorption of nutrients |
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Name the primary function of the large intestine.
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LG intestine:
-absorption of water & some minerals -storage of nondigestible remains |
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Name the primary function of the liver
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Liver:
-production of BILE |
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Name the primary function of the gall bladder.
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Gall bladder:
-storage and release of bile |
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Name the primary function of the pancreas.
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Pancreas:
-production and release of enzymes and bicarbonate into the small intestine |
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T or F:
Most digestion/absorption occurs in the small intestine. |
True. Most digestion occurs in the small intestine.
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Where does digestion occur?
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Digestion occurs in lumen and at the brush border
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Name the 3 main factors that effect absorption.
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Absorption depends on....
1.) solubility (fat vs water) 2.) conc. or electrical grad. 3.) size of the molecule |
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What does the large intestine (aka colon) do?
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The LG Intestine:
-contracts to mix matl's -the proximal colonic epithelia absorbs Na, K, and water -mat'ls dehydrated -intestinal bacteria is big (ie: gut microflora!) |
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List the segments of the large intestine (starting at the cecum, and ending with the anal canal)
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LG intestine: *{CIAMTDSRA}*
1.) Cecum, [appendix too, but not necessary] 2.) Ileocecal sphincter 3.) Ascending colon 4.) Mesentary 5.) Transverse colon 6.) Descending colon 7.) Sigmoid colon 8.) Rectum 9.) Anal canal |
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What do intestinal bacteria (aka gut microflora) do in the large intestine?
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*Fermentation - breakdown of CHO & protein anaerobically
*Generate lactate & short-chain fatty acids, gases *Probiotics - foods containing live bacterial cultures *Prebiotics - food ingredients that promote bacterial growth |
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What is a probiotic?
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Probiotics are foods that contain live bacterial cultures
(aka yogurt) |
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What is a prebiotic?
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Prebiotics are food ingredients that promote/feed bacterial growth
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List some benefits of probiotics in food.
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Probiotics:
-Enhance immunity -Prevent colonization by pathogens -Lower pH of the colon -Transform/promote excretion of toxic substances -Enhance fecal bulk |
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What causes heartburn?
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Causes of Heartburn:
-->Gastroesophageal reflux disease -->Gnawing pain in the upper chest -->Acid from the stomach to the esophagus |
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How can heartburn be treated?
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Heartburn Treatments:
-Smaller meals -Less fatty meals -Stop smoking -Do not lie down after eating -Avoid offending foods |
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What causes constipation?
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Constipation is caused by...
-antacids -Ca and Fe supplements |
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What are hemorrhoids and how are they caused?
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Hemorrhoids:
-->Swollen veins of the rectum and anus *Causes: -Added stress and pressure to the vessels |
