Fundamentals of Nutrition and Metabolism Flashcards
Symptoms of SBS don’t typically appear until ___ of the original small bowel has been resected
3/4
What anatomy yields the best prognosis for SBS patients?
All segments of the small bowel and colon in continuity
What does “jejunoileocolonic anastomosis” mean?
Colon in continuity
SBS patients with junoileocolonic anastomosis need at least ___ cm of residual small bowel
60
SBS patients with an end jejunostomy need at least ___cm of small bowel
100
SBS patients with an end jejunostomy are most difficult to manage and are most likely to require ___ ___
Permanent PN
Absorption of fat-soluble vitamins (A, D, E, and K) requires ___ ___ for emulsification and integration into ___ for absorption into the enterocyte.
- Bile salts
- Micelles
What is the first line therapy for hyperkalemic emergencies?
Calcium gluconate
How long does calcium gluconate take to onset for hyperkalemia treatment?
1-2 minutes
___-___ grams of calcium gluconate should be given over ___-___ minutes to treat hyperkalemia
- 1-2 grams
- 5-10 minutes
Calcium gluconate for hyperkalemia should be given to ___ patients or those with ___ changes to restore membrane excitability to normal.
-Symptomatic
-ECG
Calcium acts as an ___ to cardiac conduction abnormalities
Antagonist
Aside from calcium gluconate, what other therapies are available to treat hyperkalemia?
- Sodium bicarb
- Regular insulin with dextrose
How long does it take for sodium bicarbonate to onset (for treatment of hyperkalemia)?
30 minutes
How long does it take for regular insulin and dextrose to onset (for treatment of hyperkalemia)?
15-45 minutes
Name 3 oils rich in linoleic acid.
Corn, soybean, safflower
Name 2 oils that are good sources of α-linolenic acid
Soybean and canola
Diarrhea induces gastrointestinal losses of ___ and can cause a metabolic ___ (normal anion gap).
-Bicarbonate
-Acidosis
In the setting of normal anion gap metabolic acidosis, there is a milliequivalent-for-milliequivalent replacement of extracellular bicarbonate by ___.
Chloride
In addition to increased GI losses, or ___ bicarbonate losses cause hyper___ metabolic acidosis.
-Renal
-chloremic
What are the “three D’s” of pellegra?
- Dermatitis
- Diarrhea
- Dementia
What is another name for Niacin deficiency?
Pellegra
Name some food sources of niacin
Meat, fish, poultry, enriched and fortified breads, and fortified cereals.
What patients are at risk of niacin deficiency?
- Malabsorptive disorders
- Individuals with alcoholism
- Older adults
- Patients on antitubercular medications (isoniazid or mercaptopurine)
What ILE contain egg yolk phospholipid?
All clinically available ILEs contain egg yolk phospholipid as an emulsifying agent
What is the role of egg yolk in ILEs
It is an emulsifying agent
What types of IV lines can ILEs be infused through?
In addition, all currently manufactured ILEs may be safely infused via a central or peripheral intravenous line
In addition to being an energy source, four-oil and soybean oil-based fat emulsions provide ___ to prevent the development of deficiency
Essential fatty acidss
The four-oil ILE is a blend of ___% soybean oil, ___% MCT oil, ___% olive oil, and ___% fish oil.
-30
-30
-25
-15
The four oil ILE composition serves to be less inflammatory than traditional ILEs given its higher content of ___
Omega-3 fatty acids.
The four-oil ILE contains an omega-6:omega-3 fatty acid ratio of ___:___
2.5:1
What are the negative effects of EFAD?
- Increased susceptibility to infection
- Impaired wound healing
- Weight loss
- Immune dysfunction
- Rash
What is the most prominent clinical change present in EFAD?
Dry, scaly rash
In the early stages, EFAD may not present with clinical symptoms and ____ ____ may be indicated.
Biochemical testing
Mild hypercalcemia usually responds to ___ and ___ and requires no further intervention.
-Hydration
-Ambulation
Severe hypercalcemia (total serum calcium of equal to or greater than 14 mg/dL) is treated initially with ___ hydration to correct volume depletion and ___ after hydration to enhance renal calcium excretion.
-Saline
-Furosemide
When would RRT be necessary in hypercalcemia
In life threatening situations or in patients with renal insufficiency
What is the limitation of biphosphonates in treating hypercalcemia?
Bisphosphonates can assist with treatment of hypercalcemia of malignancy, but their delayed onset of action decreases the utility of these agents in the acute care setting.
Water-soluble vitamins often require ___ cotransporters for absorption.
Sodium (Na+)
Which water soluble vitamins do no require a sodium co-transport?
Vitamin B12 and folic acid
How is folate absorbed?
Via a proton-coupled folate transporter
What does vitamin B12 require for absorption?
Intrinsic factor
Intrinsic factor binds to B12 and attaches to intrinsic factor specific receptors in the ___ ___ for absorption.
Distal ileum
Vitamin C absorption occurs primarily in the ___, with some absorption in the ___ via the sodium/energy dependent ___ transport system.
- Ileum
- Jejunum
- Active
Riboflavin absorption occurs predominantly in the ___ ___ ___ via a saturable, sodium-dependent ___ mechanism.
- Proximal small intestine
- Carrier
Pantothenic acid absorption is either by ___ diffusion or via a saturable, sodium-dependent ___ transport.
- Passive
- Active
____ is the storage form of carbohydrate in the body.
Glycogen
In general, only approximately 5% of ingested glucose is polymerized into glycogen, with the majority being ___.
Oxidized
Glycogen is present in small amounts in most body tissues but is mainly found in the ___ and ___ ___.
- Liver
- Skeletal muscle
Gluconeogenesis occurs mainly in the ___, but can also occur in the ___ and ___ ___ under some conditions.
- Liver
- Kidney
- Small intestine
Prolonged nasogastric output results in a loss of ___ ___.
Gastrointestinal secretions
Hypokalemia is a common issue with continued nasogastric output as the normal potassium concentration of gastric fluid is ___mEq/L.
10
What electrolyte abnormalities occur with high NGT output?
Hypokalemia, hyponatremia, hypochloremia
Determining nitrogen balance assumes urea accounts for about ___% of total urinary nitrogen losses and non-urea (from bodily fluids) accounts for the other ___%.
- 80%
- 20%
The remaining 20% consists of non-urea nitrogen losses from body fluids.
What are the nitrogen losses from stool and skin?
Approximately 2 g nitrogen/day
This is part of the total nitrogen output considered in nitrogen balance.
What is the formula for calculating nitrogen balance?
Nitrogen Intake - Nitrogen Output
This formula is essential for determining the nitrogen balance in clinical practice.
What is the equation for nitrogen balance?
24 hr Pro intake (g) /6.25 - [24 hr UUN (g) + 20% UUN + 2]
Protein is composed of 16% nitrogen, which is why this calculation is used.
Protein is ___% nitrogen
16%
This limitation affects the common practice of nitrogen balance assessment.
What needs to be collected to complete a nitrogen balance study?
24 hour urine collection (measured in the same timeframe as protein intake)
In patients with negative pressure abdominal wound dressings and abdominal drains, additional protein losses of ___-___ grams/liter of output should be added to the output in the nitrogen balance equation.
15-30
Fat digestion begins in the mouth and stomach by ___ lipase and ___ lipase respectively
- Lingual
- Gastric
The majority of fat digestion occurs in the ___ by ___ lipase
- Duodenum
- Pancreatic
The contribution of gastric lipase is ___, but lingual lipase hydrolyzes up to ___% of dietary fat
- Small
- 10%
In a healthy 70 kg male, the liver contains approximately ___ grams of glycogen, potentially providing ___ kcal.
- 100
- 390
Skeletal muscle contains about ___-___ grams of glycogen, yielding less than ___ kcal, suggesting that an adult stores only enough glycogen for about ___ ___ of normal activity.
- 300-400
- 1560
- 1 day
Because glycogen is stored with ___, this is a somewhat inefficient storage method.
Water
What are some etiologies of hypokalemia?
- Losses via the urine or stool
- Shift of potassium from the extracellular fluid into cells
- Inadequate dietary intake
- Medications
- Sorbitol (losses in the the stool)
Soluble dietary fiber may ___ total cholesterol and LDL cholesterol without changing or lowering HDL cholesterol levels.
Lower
Does soluble fiber lowers the risk of developing colon cancer or recurrence of adenomas?
No. There is currently no clear evidence to support that soluble fiber lowers the risk of developing colon cancer or reducing recurrence of adenomas.
How might soluble fiber affect blood sugar levels?
Consumption of soluble fiber may result in small decrease of plasma glucose and hemoglobin A1c.
When does mucosal atrophy occur?
During periods of bowel rest, minimal PO intake, and stress.
___ is a principal metabolic fuel for intestinal cells.
Glutamine
An absence of glutamine may directly contribute to ___ ___.
Mucosal atrophy
Atrophic changes during bowel rest have been decreased with ___-enriched parenteral nutrition.
Glutamine
What is the basic structure of a triglyceride?
Hydroxylated 3-carbon backbone (glycerol). Attached in an ester linkage at the carbon-1, carbon-2, and carbon-3 positions of the glycerol structure are various fatty acids.
Insoluble fiber ____ stool water content, stool bulk and weight
Increases
What is the role/benefits of insoluble fiber?
It speeds the movement of material through the gastrointestinal system to promote regularity of bowel movement
Soluble dietary fiber dissolves in water to create a ___-like material which ___ gastric emptying and has the effect of ___ cholesterol and glucose levels.
- Gel
- Delays
- Lowering
Soluble dietary fiber is fermented in the ___
Colon
Soluble fiber promotes ___ bacterial growth
Colonic
Soluble fiber adds to ___ mass which may ___ evacuation.
- Fecal
- Ease
IC is the calculation of energy expenditure by analysis of ___ exchange
Gas
IC measures ___ consumptions and ___ production
- Oxygen consumption
- CO2 production
The Haldane transformation implies that the inert gas nitrogen (N2) is ___ in both inspired and expired gases.
Constant
If the fraction of inspired oxygen (FiO2) is ≥___f%, the risk of error on the denominator increases.
60
What is the accuracy of IC measurement dependent on?
Patient, environmental and equipment related factors
FiO2 needs to remain ___ during the IC measurement.
Constant
IC measurements should be made in a ___, thermo___ environment and routine care during the study should be ___.
- Quiet
- Thermoneutral
- Avoided
The rate and composition of nutrients being infused should be stable for at least ___ hours for an accurate IC study.
12
Trophic enteral nutrition is the amount of substrate necessary to provide ___ ___, usually 10-20mL/hr.
Gut stimulation
What did studies comparing trophic and full feedings in the first week of ICU find regarding ventilator days, 60 day mortality and infectious complications?
In the EDEN study comparing trophic and full feedings found no difference in the first week of ICU in ventilator days, 60 day mortality or infectious complications
Name the benefits of EN in the critically ill patient?
- Preserve gut integrity
- Preserve immune function
- Prophylaxis against GI bleeds
- Modulate stress
Trimethoprim induces what electrolyte abormality?
Hyperkalemia
Trimethoprim impaires renal ___ excretion
Potassium
What 2 hormones have increased production during periods of illness and trauma?
Epinephrine and cortisol
What 2 hormones are elevated during periods of illness and trauma?
Growth hormone and glucagon
Name the 4 counterregulatroy hormones
Epinephrine, cortisol, growth hormone and glucagon
The counterregulatory hormones work to oppose ___ action
Insulin
Increased counterregulatory hormone result in increased glucose production by the ___ (up to ___ mg of glucose per day)
- Liver
- 500
Increased counterregulatory hormones lead to a ___ utilization of glucose in ___ tissues.
- Decrease
- Peripheral
Increased counterregulatory hormones increased protein breakdown from ___ and enhanced fatty acid ___
- Muscle
- Oxidation
What the the biological mechanism behind the breakdown of muscle and fatty acids during times of stress?
Viewed as a metabolic adaptation to provide fuels for heightened demands.
What are mitochondria primarily responsible for?
Generating ATP via oxidative phosphorylation
What is the major source of cellular energy?
Oxidative phosphorylation
Fatty acids are transported into the ___ membrane and through the ___ pathway the fatty acid is degraded and released as ___.
- Mitochondria
- Beta oxidation
- ATP
True or False: Red blood cells contain mitochondria.
False
Fatty acid (and/or lipid) oxidation releases substantially ___ energy than does oxidation of carbohydrate
More
Adipocytes store energy as ___
Fat
How do RBCs make energy?
They rely on glycolysis to generate ATP
Choline is required for ___ transport and metabolism.
Lipid
Low plasma choline levels in patients on long-term PN have been associated with elevated ___ ___ concentrations.
liver aminotransferase
Investigations reported that steatosis ___ following choline supplementation.
Resolved
Is choline a component of PN?
No. Currently PN admixtures do not contain choline.
MCTs are hydrolyzed and pass through the ___ directly into the ___ circulation.
- Enterocyte
- Portal
The liver is a key organ for ___ metabolism because of its high capacity for uptake and metabolism of ___ ___.
- Protein
- Amino acids
About 57% of the amino acids extracted by the liver are either ___ or used to synthesize ___ proteins.
- Oxidized
- Plasma
Name the signs of vitamin D toxicity
- Confusion
- Psychosis
- Tremor
- Hypercalcemia
- Hypercalciuria
Soft tissue calcification may occur with long-term vitamin ___ toxicity in lungs and cardiovasculature
Vitamin D
Name the symptoms of vitamin D deficiency
- Hypocalcemia
- Osteomalacia
- Tetany
- Osteoporosis
Why is glucose utilization reduced in starvation?
Because of a reduced supply of glucose and decline in circulating insulin concentration
Higher ___ concentrations promote fatty acid oxidations in starvation.
Glucagon
In starvation, ___ tissue becomes the main energy source for nearly all tissues.
Fat
After 14 days of fasting, ___ tissue can provide more than 90% of daily energy requirements.
Adipose
What can be measured to reflect long-term selenium status?
Plasma glutathione peroxidase
What lab value of plasma glutathione peroxidase indicates selenium deficiency?
<10.5 U/mL
Aside from plasma glutathione peroxidase, how else can selenium status be assessed?
By determining the selenium level in whole blood, plasma, serum, or erythrocytes.
Plasma or serum level is reflective of ___ selenium intake
Recent
Levels greater than ___mcg/L represent adequate selenium status in adult patients
100
Serum ceruloplasmin levels are useful in assessment in ___ status.
Copper
Pancreatic exocrine deficiency may develop in patients with ___ diseases
Pancreatic
What are symptoms of pancreatic insufficiency?
- Diarrhea
- Abdominal pain
- Distention
- Bloating
- Cramps
- Flatulence
- Weight loss
Pancreatic enzyme replacement therapy may help with improvement of ___ and nutrition/quality of life.
Digestion
How should soluble fiber be administered via a feeding tube?
Soluble fiber should be administered via feeding tubes by diluting with water per manufacturer directions, injecting by syringe and following with 15 - 30 mL water flush.
How should medications be administered via a feeding tube?
Medications should flushed one at a time and should not be mixed with any other enteral components.
Hydrochloric acid secreted by the ___ cells of the stomach denatures the protein and makes it more susceptible for ___ action.
- Parietal
- Enzymatic
HCL converts the inactive pepsinogen to active ___.
Pepsin
Pepsin activates other pepsinogen molecules or hydrolyzes specific peptide bonds into end products of large ___peptides, ___peptides and free ___ ___.
- Polypeptide
- Oligopeptides
- Amino acids
Pepsin breaks down molecules into a mixture known as ___.
Chyme
Chyme enters into the ___ where majority of protein digestion takes place.
Duodenum
Where does the majority of protein digestion take place?
Duodenum
Why are linoleic and α-linolenic acid considered essential fatty acids?
They cannot be synthesized naturally by humans and must be supplied exogenously via the diet
What is a consequences of essential fatty acid deficiency (EFAD)?
Metabolic complications
What can all fatty acids be oxidized to produce?
ATP
What is required for linoleic acid and α-linolenic acid to enter the mitochondria?
L-carnitine
What is the carbon chain length of linoleic acid and α-linolenic acid?
> 10 carbons
What equation does IC use?
Abbreviated Weir equation
What does total energy expenditure include?
- Resting metabolic rate (RMR)
- Energy required for the thermogenic effect of digestion
- Energy expenditure associated with physical activity
Nitrogen balance is determined using urine ___.
Urea
Heat released from the subject is measured by ___ ___, which requires the subject to remain inside of an enclosed chamber during the measurement
Direct calorimetry
What are “simple” sugars
- Monosaccharides (one sugar unit)
- Disaccharides (two sugar units).
Name 3 monosaccarides
- Glucose
- Fructose
- Galactose
The monosaccharides are water ___ and have ___ molecular weight.
- Soluble
- Low
Polysaccharides are multiple units of ____ and ___ joined together (complex carbohydrate)
- Monosaccharides
- Disaccharides
Polysaccharides are water ___ and have ___ molecular weights
- Insoluble
- High
Dietary folate is converted to monoglutamate by ___ enzymes for entry into the ___ cell.
- Jejunal
- Intestinal
What must folate be converted to in order to enter the intestinal cell?
Monoglutamate
Monoglutamate undergoes further reduction before entry into the ___ circulation for reabsorption via ___ circulation
- Portal
- Enterohepatic
Name some factors that would limit folate absorption
- Zinc deficiency
- Chronic alcohol consumption
- Changes in jejunal luminal pH
- Impaired bile secretion
The average nitrogen content of protein was determined to be ___%.
16%
The total grams of protein multiplied by ___ will determine the nitrogen content of protein in a PN solution.
0.16
What is bile compromised of?
Bile salts, bile pigments, cholesterol, lecithin, alkaline phosphatase and electrolyes
Bile salts are ___ and ___ salts of bile acids
Sodium and potassium
Bile salts are metabolites of ___
Cholesterol
Bile salts form ___ in which their hydrophilic portions face out and their hydrophobic portions face toward the center where lipids collect
Micelles
Where do lipids collect in a micelle?
In the center
Lipids are transported to the ___ ___of the intestine where they are absorbed
Brush border
When given at therapeutic doses, ___ becomes the predominant biliary bile acid and is thought to displace potentially hepatotoxic bile salts.
Ursodiol
A deficiency in brush border oligosaccharidases allows osmotically active, undigested oligosaccharides to cause a shift of ___ into the intestinal lumen
Water
When brush border oligosaccharidases are deficient; colonic bacteria act on remaining oligosaccharides, thus increasing the number of ___ ___ particles.
Osmotically active
Formation of ___ and ___ from disaccharides increases flatulence and bloating
CO2 and hydrogen
Vitamin B12 requires ___ ___ for absorption.
Intrinsic factor
Intrinsic factor, a glycoprotein is secreted by the ___ cells of the stomach
Parietal
IF binds to ___ and is taken up by receptors in the distal ileum.
Cyanocobalamin/B12
What might predispose someone to B12 deficiency?
Loss of parietal cells for any reason:
1. Gastrectomy
2. Pernicious anemia,
3. Chronic gastritis)
Also:
1. Loss of distal ileum
Glucose and sodium share common co-___.
Transporters
High concentrations of sodium in the chyme ___ glucose transport. Low concentrations of sodium ___ glucose absorption.
- Increase
- Decrease
Sodium moves into mucosal cells along its concentration gradient and brings ___ along.
Glucose
The ___ transport of sodium out of the cell provides the energy for ___ transport.
- Active
- Glucose
The transport of sodium out of the cell maintains the ___ ___ needed for sodium to shuttle more glucose into the mucosal cells.
Concentration gradient
When soluble fiber is added to a liquid meal, it slows the rate of gastric emptying due to increased ___.
Viscosity
Avoid insoluble and soluble fiber foods/medications with a ___ formation.
Bezoar
Insoluble fiber has stool ___ effects which result in ___ transit time and more ___ bowel movements, providing relief from ___.
- Softening
- Faster
- Frequent
- Constipation
Soluble fiber is fermented in the distal ____ & increases intestinal mucosal growth and promotes ___ and ___ absorption.
- Intestine
- Water
- Sodium
___ is the endogenous formation of glucose.
Gluconeogeneis
Some studies have shown that enteral formula containing soluble fiber reduces the incidence of ___
Diarrhea
The ___, ___ ___, and ___ all have the necessary enzymes to perform gluconeogenesis.
Liver, small intestine and kidney
The ___ is the main site for gluconeogesesis
Liver
Diuretic therapy can cause metabolic acidosis due to a loss of fluid that is high in ___ and low in ___.
- Chloride
- Bicarbonate
Since the original bicarbonate mass is now dissolved in a smaller fluid volume, an increase in bicarbonate concentration occurs resulting in metabolic alkalosis.
Arginine is a semi-essential amino acid that has demonstrated importance in ___ function and ___ ___.
- Immune
- Wound healing
Is arginine supplementation recommended?
Supplementation with arginine in the critically ill septic patient population remains controversial.
What is the most abundant amino acid in the body?
Glutamine
Glutamine is vital fuel for ___ ___ cells
Vital fuel for rapidly dividing cells, such as enterocytes, fibroblasts, reticuloendothelial cells, and malignant cells.
In some conditions, such as trauma, sepsis, and exercise, the body’s glutamine requirement ___ the rate of synthesis leading to a ___ in plasma and intracellular glutamine.
- Exceeds
- Decrease
What is associated with a decrease in glutamine levels?
- Intestinal mucosal atrophy
- Impaired immune function
- Decreased protein synthesis
What is carnitine?
Carnitine is a trimethyl amino acid
Carnitine similar in structure to ___
Choline
What is the role of carnitine in the body?
Carnitine is required as a cofactor for transformation of free long-chain fatty acids into acylcarnitines and transport into the mitochondria
What causes primary carnitine deficiency?
Primary carnitine deficiency is due to a gene defect which has been documented in preterm infants
What are the causes of secondary carnitine deficiency?
Secondary carnitine deficiency is due to increased urine excretion, malabsorption or insufficient intake
List some conditions associated with secondary carnitine deficiency.
- Metabolic disorders
- Valproate therapy
- Malabsorptive GI disorders
- Dialysis
- Liver disease
- Malnutrition
- Mitochondrial disorder
- Long term PN therapy
What is the role of transport proteins?
in plasma bind and carry specific molecules or ions from one organ to another.
What types of things do transport proteins carry?
- Lipids
- Vitamins
- Minerals
- Albumin
- Oxygen
Hemoglobin, the (___-containing protein of blood), transports oxygen from the ___ to the cells.
- Iron
- Lungs
What is the most serious complication of hyperphosphatemia?
Metastatic calcification of non-skeletal tissues (soft tissue and vascular calcification).
Metastatic calcification of non-skeletal tissues may occur when the calcium-phosphorus product exceeds ___ mg2/dL2.
55
Aside from metastatic calcification of non-skeletal tissues, what are 2 additional consequences of hyperphosphatemia?
Secondary hyperparathyroidism and renal osteodystrophy
Oral rehydration fluids used to treat diarrhea should contain both ___ and ___.
NaCl and glucose
Because of the profound lean body mass loss that is associated with critical illness, ___ needs are elevated.
Protein
The current recommendation for stressed trauma patients is that 20-25% of total nutrient intake be provided as protein. This equates to roughly ___-___g/kg/day.
1.5-2.0
Patients receiving continuous renal replacement therapy and those with a BMI >30 kg/m2 should receive ___-___g/kg/day.
2.0-2.5
Serum albumin is a visceral (hepatic) protein and has a half-life of ___-___ days.
14-20
What is the half life of retinol-binding protein?
12 hours
What is the half life of prealbumin protein?
2-3 days
What is the half life of transferrin protein?
8-10 days
The brain and red blood cells require a constant supply of ___.
Glucose
The breakdown of hepatic glycogen stores (glycogenolysis) for glucose production begins within ___-___ hours of fasting, but its stores are depleted within ___ hours.
- 2-3
- 24 hours
Gluconeogenesis from amino acid substrate begins within ___-___ hours after the last meal.
4-6
After approximately 2 days of starvation, the brain switches its fuel source from glucose to ___ ___.
Ketone bodies
The liver converts free fatty acids to ___ bodies.
Ketones
The adaptation to starvation with a ketone-based fuel system minimizes ___ and further ___ breakdown.
- Gluconeogenesis
- Protein
What are phytobezoars?
Retained indigestible materials that accumulate in the stomach.
What treatments are available for phytobezoars?
Treatment can include enzymatic therapy such as cellulase with lavage and endoscopic intervention.
Long-term prokinetic therapy can treat and prevent bezoar formation.
Case studies have shown oral cola and acetylcysteine infusions to be effective for treating ___.
Phytobezoars
Are meat tenderizer that contains papain recommended for phytobezoar treatment?
Meat tenderizer that contains papain has also been reported in the literature but is not recommended as it damages normal tissue which can lead to peptic ulcer disease, esophagitis and gastritis.
In refractory cases of phytobezoards, surgery offers a ___ solution.
Definitive
The overwhelming majority of enteral dietary lipids (approximately 90%) are ingested in the form of ___.
Triglycerides
Bile acids are detergent-like derivatives of cholesterol produced by the ___, which aid in ___ emulsification and the formation of micelles in the small intestine.
- Liver
- Triglyceride
The triglyceride emulsification process and micelle formation makes triglycerides and fatty esters available for ___ by intestinal lipases and esterases.
Hydrolysis
Fatty acids of up to ___ carbons in length and glycerol can be absorbed directly via the villi of the intestinal mucosa.
10
Long-chain triglycerides require ___ ___ for both enzymatic digestion and formation of micelles.
Bile salts
Hypocaloric enteral nutrition feedings are ___-___% of energy requirements.
60-70%
Patients who are obese are thought to potentially benefit from ___ feeding (with high ___) compared to normal weight patients.
- Hypocaloric
- Protein
Decreased protein provisions are indicated in ___ status
Uremic
Low intake of protein in combination with a hypocaloric diet may worsen ___ in obese patients.
Mortality
When should hypocaloric feeding should be considered?
When enteral nutrition feeding is associated with:
- Poor glycemic control
- Respiratory acidosis
- High serum triglyceride concentrations
What is the role of HCL and pepsin in Vitamin B12 absorption?
They release Vitamin B12 from ingested proteins.
What conditions can lead to reduced absorption of Vitamin B12?
- Pancreatic insufficiency
- Impaired HCl production
- Resection of ileum or stomach
- Chronic malabsorption.
Which patient groups may experience impaired HCl production?
- Older patients
- Those with Helicobacter pylori infections
- Those taking histamine-2 antagonists or proton pump inhibitors
In which part of the intestine does Vitamin K absorption primarily occur?
In the jejunum.
Where does Vitamin B1 (thiamin) absorption primarily take place?
In the proximal small intestine, especially in the jejunum.
Where is Vitamin A primarily absorbed?
In the upper small intestine.
Fill in the blank: Vitamin B12 is dependent on normal _______ function.
GI
What does the Swinamer Equation predict?
Resting metabolic rate (RMR)
What does the Swinamer Equation use to predict RMR?
Uses body surface area in addition to physiological variables
This Swinamer equation has been found to predict ___ in about 55% of patients.
RMR
Mifflin-St. Jeor Equation and Harris-Benedict Equation use ___, ___, and ___
Height, weight and age
What criteria does the Ireton-Jones Equation use?
Weight, height, age, sex, as well as trauma, and burn
Chromium potentiates the action of ___
Insulin
What does chromium help metabolize?
Glucose, protein and lipid metabolism.
Chromium deficiency impairs glucose and amino acid use which may result in ___.
Hyperglycemia
What does AMDR stand for?
Acceptable Macronutrient Distribution Range
AMDR is related to energy intake and chronic disease risk.
What is the purpose of the AMDR?
To associate reduced risk of chronic disease while providing adequate essential nutrients
AMDR is set for carbohydrate, protein, and fat including Omega-3 and Omega-6 fatty acids.
What nutrients does the AMDR include?
- Carbohydrates
- Protein
- Fat
- Omega-3 fatty acids
- Omega-6 fatty acids
AMDR is set for these macronutrients.
What is the tolerable upper intake level?
The highest level of daily nutrient intake likely to pose no risk of adverse health effects to almost all individuals
This applies to the general population.
What does EAR stand for?
Estimated Average Requirement
EAR is related to nutrient intake levels.
How is EAR defined?
The average daily nutrient intake level estimated to meet half the needs of healthy individuals in a particular life stage and gender group
This helps in assessing nutrient adequacy.
Presence of fat in the distal ileum produces an inhibitor feedback effect called the “___ ___,” which slows gastric emptying and intestinal transit.
Ileal brake
The ileal brake ___ gastric emptying and intestinal transit
Slows
Some types of fiber are fermented by bacteria in the colon into ___
Short chain fatty acids
The acute phase response to injury and infection suppresses iron ___.
Transport
In the acute phase response, serum iron levels are ___, while serum ferritin levels are ___.
- Decreased
- Increased
The sequestering of iron into a ___ form following injury and infection is thought to have several protective measures.
Storage
How is the sequestering of iron into the storage form protective in the acute phase response?
Iron in his storage form during the acute phase response reduces iron dependent microorganism proliferation and reduces potential for free radical production and the subsequent oxidative damage to cell membranes and DNA.
Copper accumulation in the liver and other organs can occur in ___ disease
Wilson’s
What is Wilson’s disease?
Characterized by a genetic mutation of copper metabolism.
Normal copper homeostasis is maintained via ___ excretion.
Biliary
Copper toxicity can occur with impaired ___ excretion.
Biliary
Glucose and galactose are transported from the intestinal lumen into the enterocyte via the ___.
SGLT-1
The SGLT-1 transport process requires energy provided by hydrolysis of ___ and is, therefore, called an ___ transport system.
- ATP
- Active
___ molecules of sodium are cotransported with ___ molecule of glucose or galactose.
- Two
- One
70%-100% of African Americans, Native Americans, Asian, and Mediterranean descendents are deficient of ___ enzyme.
Lactase
What is the treatment for lactose intolerance?
Low lactose diets or supplemental oral lactase improves dietary tolerance.
Fatty acids are molecules with an acidic ___ group at one end followed by a long chain of hydrogenated hydrophobic ___ atoms.
- Carboxyl
- Caron
Short chain fatty acids have ___-___ carbons
2-4
Medium chain fatty acids have ___-___ carbons
6-12
Long chain fatty acids have ___-___ carbons
14-18
Very long chain fatty acids have ___-___ carbons
20 carbons or more
Butyric acid contains ___ carbon atoms and is classified as a ___ chain fatty acid.
- 4
- Short
Lauric acid contains ___ carbon atoms is a ___ chain fatty acid.
- 12
- Medium
Stearic acid and oleic acid are ___ chain fatty acids containing ___ carbon atoms each.
- Long
- 18
Pancreatic lipase, cholesterol ester hydrolase, and phospholipase are all pancreatic enzymes involved in ___ digestion.
Fat
Enzymes that digest fat hydrolyze triglycerides, phospholipids, cholesterol esters, and fat-soluble vitamins in the ___
Duodenum
The role of bile salts in fat digestion is to act as ___.
Emulsifiers
What percentage of body weight does water constitute?
Approximately 50% to 60%
Water is the most abundant substance in the body.
What factors influence total body water (TBW)?
Weight, age, gender, and relative amount of body fat
TBW varies among individuals based on these factors.
Which body tissue is the least hydrated?
Adipose tissue
Individuals with more body fat have proportionally less TBW content.
What are the two main compartments of total body water (TBW)?
Intracellular fluid (ICF) and extracellular fluid (ECF)
TBW is distributed between these two compartments.
What percentage of total body water is contained in the transcellular fluid compartments?
Approximately 3 percent
TCF is a small component of TBW.
What proportion of total body water is contained in the intracellular fluid (ICF)?
Two-thirds
The remaining one-third is in the extracellular fluid (ECF).
What proportion of extracellular fluid (ECF) is in the intravascular space?
One-fourth
The remaining three-fourths is in the interstitial space.
Know how to calculate the total body water, ECF and ICF in liters for a patient when given just their weight in kg
Calculations for an 80 kg patient are: TBW: (80 x 0.6) = 48 L; Extracellular fluid: (1/3 x 48) = 16 L; Intravascular space: (1/4 x 16) = 4 L.
Calculation: TBW = 80 x 0.6.
Use of fiber-containing formulas can cause abdominal distention and bloating because fiber ___ and produces ___ in the gut.
- Ferments
- Gas
High doses of fiber tend to ___ gastric emptying.
Delay
In a diabetic patient, increased time to empty the stomach may result in a ___ peak in postprandial glucose concentration.
Smaller
How can complications of fiber (such as constipation, impaction and intestinal bezoar formation) be reduced?
Adequate fluid provision
