Final Review Flashcards
What are the possible effects of exposure to toxins during the pre-implantation period? Why?
- No effect, slight decrease in growth, or lethality
- As the fate of the cells has not yet been determined (pluripotent nature), providing them with great restorative capacity
- Also, there is a decreased exposure to toxins due to poorer accessibility of the conceptus (not yet attached to uterine wall)
What type of drug is Dilantin? What defects does it result in?
- Anti-epilectic drug
- Fetal hydantoin syndrome
What type of drug is Thalidomide? What defects does it result in?
- Immunomodulatory drug
- Limb and ear abnormalities
What type of drugs are antineoplastic drugs? What defects do they result in?
- Chemotherapy drug
- Congenital abnormalities
What type of drug is Diethylstilbestrol? What defects does it result in?
- Endocrine disruptor
- Uterine and cervical defects
What type of drug is Dextromethorphan? What defects does it result in?
- Cough-suppressant
- CNS abnormalities
What are the effects of excess fluoride?
Spina bifida occulta
What are the effects of iodine deficiency? What are its characteristics?
Cretinism
Which nutrient deficiencies are anti-convulsants associated with?
Folate and zinc deficiencies
What are characteristics of alcohol-related birth defects (ARBD)?
- Microcephaly
- Heart and lung malformations
- Minor physical abnormalities
Differentiate anencephaly and exencephaly.
- Anencephaly implies that the brain is exposed, due to the lack of skull
- Exencephaly implies that the brain protrudes out of the skull
What substances does the placenta synthesize for fetal use?
- Glycogen
- Lactate
- Cholesterol
What indicator is used to estimate the requirements (RDA) for carbohydrates?
Minimum amount of glucose required by the brain without depending on fat or protein as an alternative source
What indicator is used to estimate the requirements (AI) for dietary fiber?
Median intake observed to achieve the lowest risk of coronary artery disease
What are the four benefits of fiber? (4)
1) Amelioration of constipation and diverticular disease
2) Fuel for colonic cells
3) Decrease in blood glucose and lipids
4) Acting as a source of nutrient-rich low-energy foods (increases satiety and decreases obesity)
What DRI is used to estimate the requirement for magnesium? How is it established?
- RDA
- Based on total body magnesium, assessed using balance studies
What DRI is used to estimate the requirement for potassium? How is it established?
- Adequate Intake (AI)
- Based on the physiological functions of an adequate intake of potassium
What is the importance of organic anions that are associated with potassium?
- They are converted to bicarbonate after absorption
- Bicarbonate may act as a buffer to neutralize acids from the diet
What occurs if there is a deficiency in bicarbonate precursors?
The body must use another type of buffer, which is normally drawn from the bone matrix, leading to increased bone turnover
Where is potassium largely contained?
Intracellularly
What is the major function of riboflavin?
Functions as a coenzyme in various oxidation-reduction reactions, involved in several metabolic pathways and energy production
What three factors determine the requirement for riboflavin? (3)
1) Erythrocyte glutathione reductase activity coefficient
2) Concentration of riboflavin in RBCs
3) Urinary riboflavin excretion
What determines the requirement for niacin?
Urinary excretion of niacin metabolites, as an excess of niacin is methylated in the liver for excretion in urine
What DRI is used to estimate the requirement for choline? How is it established? What factor does it take into consideration?
- AI
- Assessed by serum alanine aminotransferase levels
- The prevention of liver damage
What factor determines the requirement for vitamin E?
- The correlation between hydrogen peroxide-induced erythrocyte lysis and blood a-tocopherol
- Analysis of the level of a-tocopherol that protects against hemolysis caused by hydrogen peroxide
What is the difference between tocopherols and tocotrienols?
- The side chain of tocopherols are saturated
- The side chain of tocotrienols are unsaturated
The concentration of the various forms of vitamin E in plasma are dependent on what?
Their affinity with hepatic a-tocopherol transfer protein (a-TTP)
How does the recommendation for potassium vary during pregnancy?
The AI does not change
How does the recommendation for biotin (vitamin B7) vary during pregnancy?
The AI does not change
How does the recommendation for vitamin E vary during pregnancy?
The RDA does not change
What are the two factors that increase the requirement for folate during pregnancy?
1) Single-carbon transfer reactions
2) Nucleotide synthesis (cell division)
What is the composition of foremilk? Why?
- Contains a high quantity of water and lactose
- Due to the increased hydration needs of the child
Which minerals does xanthine oxidase supply?
Iron and molybdenum
Which minerals does lactalbumin supply?
Calcium and zinc
Which mineral does glutathione peroxidase supply?
Selenium
Which minerals does alkaline phosphatase supply?
Zinc and magnesium
Why is soy milk protein not recommended for infant consumption?
- Lower bioavailability of minerals (zinc, calcium, iron), as phytic acid complexes with these minerals, which prevents their absorption
- Decreased calcium and phosphorus retention
- Decreased bone density
How does pre-term milk compare to term milk?
- Pre-term milk is higher in energy, protein, sodium and chloride
- Pre-term milk is lower in lactose
What are the effects of PCBs and dioxins in breast milk?
- May interfere with vitamin K metabolism
- Linked to the late hemorrhagic disease of the newborn
How does breast milk jaundice develop?
- As metabolites of progesterone travel to the infant’s bloodstream
- Specifically, 5B-pregnane-3a,20B-diol
- Inhibits bilirubin conjugation by glucoronyl transferase
- Jaundice occurs as bilirubin accumulates
How does the recommendation for potassium vary during lactation?
The AI increases
How does the recommendation for biotin vary during lactation?
The AI does not change
What are the three reasons that explain for a high blood phosphorus level during lactation? (3)
1) Increase in bone resorption
2) Decrease in blood PTH, increasing serum inorganic phosphate concentration
3) Decrease in urinary excretion
What factor is the basis of the additional manganese requirements during lactation?
- It is based on the AI
- There is no evidence of manganese deficiency in North America
- The AI is based on the median intake of the healthy population
What are risks associated with the introduction of solid foods too late?
- Growth faltering
- A decrease in immune protection
- Feeding aversion
- Undernutrition (exclusive breastfeeding may become inadequate)
What are internal factors that influence eating behaviour?
- Physiological needs and characteristics
- Body image
- Self-concept
- Personal values and beliefs
- Food preferences and meanings
- Psychosocial development
- Health
How does a decrease in nutrient and energy intake cause hormonal changes? What are their effects?
- Increase in cortisol
- Decrease in IGF-1 and leptin
- Slow down bone formation and increase bone loss
What are the four diagnostic criteria for bulimia? (4)
1) Individual is binging and purging over once per week for at least three months
2) Involves compensatory behaviours to prevent weight gain
3) Possess a distorted or ill-informed attitude regarding food and nutrition
4) Often self-evaluate according to body shape and weight, possessing a fear of gaining too much weight
What are the four diagnostic criteria for binge-eating disorder? (4)
1) Loss of control over the amount of eating
2) Marked distress over the binge episode
3) Occurs at least once per week for three months
4) Three or more of typical characteristics
What equation is used to predict the TEE for individuals aged 0 to 2 years old? How does it vary between boys and girls?
- EER = TEE + Energy Deposition
- It does not vary between sexes
How is potassium citrate related to kidney disease?
- Potassium citrate is a precursor for bicarbonate
- Acts to counteract the calcium-carbonate release, which retards kidney disease or calcium-containing kidney stones
Why is the requirement for potassium in children and adolescents based on energy intake and not weight?
Because basing the requirement on weight may lead to relatively low and potentially inadequate intake of potassium
How is the AI of vitamin K for infants aged 6 to 12 months determined?
It is extrapolated up from the AI of infants aged 0 to 6 months
When does middle adulthood occur?
50 to 69 years old
What was the purpose of the Mozaffarian (2016) study?
Combined several meta-analyses to determine the effects of certain foods on death from coronary heart disease, stroke and diabetes
Define frailty.
Frailty is a classification that includes 3 or more of the following characteristics:
- Muscle weakness
- Slow walking speed
- Exhaustion
- Low physical activity levels
- Unintentional weight loss
What increases the risk of peptic ulcer disease among the elderly? Which populations are particularly at risk?
- Decrease in stomach lining capacity to allow for the resistance to damage
- Particularly in individuals that consume aspirin and NSAIDs, such as ibuprofen
What are causes of dysphagia? (3)
- CNS changes
- Diabetic neuropathy
- Parkinson’s disease
What are the effects of a decrease in pepsin due to aging?
- Decreases proteolysis
- Results in a decreased vitamin B12 exposure to intrinsic factor
- Decreased absorption of vitamin B12
What is the effect of bacterial overgrowth of the small GI?
These bacteria compete for B-vitamins, which decreases optimal nutrient availability
Which nutrient deficiencies are related to lactose intolerance?
- Vitamin A
- Vitamin D
- Vitamin B2
- Protein
What is the effect of the decrease in function of the liver AND kidney?
- Accumulation of drug metabolites
- May trigger a type III hypersensitivity response
How do antibiotics affect nutrient metabolism?
- Damage to the GI tract
- Destroying intestinal mucosa, villi and microvilli, as well as brush-border enzymes
- Reduces nutrient absorption
How do anti-inflammatory drugs affect nutrient metabolism? (3)
1) Inhibit lactase
2) Directly damage the gut
3) Decrease fat and micronutrient absorption
Which nutrient do loop diuretics affect?
Increase the renal excretion of thiamine
Which nutrients do thiazide diuretics affect?
- Increase the excretion of potassium and magnesium
- Reduce the excretion of calcium
Which nutrients do potassium-sparing diuretics affect?
Increase the excretion of sodium, chloride and calcium
What are the three factors that place men at a decreased risk for developing osteoporosis? (3)
1) Their larger skeleton
2) Bone loss starting later and slower in men
3) The lack of rapid hormonal changes in men
How does the vitamin D requirement vary in the elderly? Why?
- The requirements are increased
- The absorption decreases, likely due to a decreased number of vitamin D receptors
What are the dietary recommendations of vitamin D based on?
The amount of vitamin D to maintain blood levels of calcitriol associated with optimal bone health
What is the effect of vitamin A on folate metabolism?
Decreases 5-methyl-tetrahydrofolate reductase capacity
Differentiate IUGR and SGA.
- IUGR: rate of fetal growth is below the 10th percentile
- SGA: does not take in-utero growth into consideration (below the 10th percentile)
- IUGR is the likely cause of SGA
Name 5 reasons why breastfeeding is nutritionally superior to formula or cow’s milk.
- Increased calcium to phosphorus ratio
- High taurine
- Low methionine, high cysteine
- Low phenylalanine, low tyrosine
- High whey to protein ratio
- High non-protein nitrogen
Name three examples of growth factors present in breast milk.
- Polyamines
- Prostaglandins
- Insulin, thyroxine and cortisol
What is the composition of colustrum?
- High protein and minerals
- Low in energy, fat, and lactose
