Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NUTR 207 > Midterm 2 Section 3 > Flashcards

Midterm 2 Section 3 Flashcards

1
Q

micronutrients definition

A

needed in small (mg/microgram) amounts in the diet

metabolically essential nutrients (not synthesized, perform specific functions, deficiency will result without intake)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why do metals need to be bound?

A

they are toxic when free

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

where/how are minerals synthesized?

A

in the sun or in nuclear reactors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

major minerals
minerals in 60kg person

A

Ca, P, K, S, Na, Cl, Mg
Ca - 1150g, P - 600g, K - 210g, S - 150g, Na - 90g, Cl - 90g, Mg - 30g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Trace minerals
trace minerals in 60kg person

A

Fe, Zn, Cu, Mn, I, Se
Fe - 2.4g, Zn - 2g, Cu - .09, Mn/I/Se - .02g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

electrolyte minerals
Na-K balance, where in cells

A

K, Na, Cl, Mg
K inside cells, Na outside cells (tears taste salty)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

vitamins
vitamers

A

essential organic micronutrients
different forms of vitamin with different functions and conversion between forms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

B vitamins function
examples of functions B1-B6 (no B4)

A

function as coenzymes in intermediary metabolism
B1 (thiamine) - TTP (thymidine triphosphate) for pyruvate decarboxylation
B2 (riboflavin) - FAD, FMN
B3 (Niacin) - NAD, NADP
B5 (pantothenic acid) - acetyl coA
B6 (pyroxidine, RDA based on protein intake) - PLP in transamination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

types of bone

A

cortical bone - compact bone that makes up the outer surface, and 80% of all bone

trabecular bone - spongy scaffolding bone that makes up 20% of bone and supports cortical bone
examples of trabecular bone: ends of long bones and vertebrae, metabolically active including RBC formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

bone resorption
bone formation
osteoblasts produce

A

surface of bone is broken down by osteoclasts

osteoblasts synthesize new bone in resorption pits

osteoblasts produce collagen component of bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

osteoporosis
prevalence stats in Canada

A

degradation of mostly trabecular bone
vertebrae lose bone mass and compress
bones become susceptible to fracture

prevalence: 30% of women, 20% of men

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

screening for osteoporosis

A

DEXA scan pre and post menopause as a lot of bone loss happens during this time (20%)
osteoporosis is a pediatric disease
DEXA is low dose radiation and non-invasive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

osteopenia vs osteoporosis
T score means

A

of standard deviations below the mean established for young, healthy population

osteopenia: bone mineral density -1 to -2.5 T score
osteoporosis: bone mineral density >-2.5 T score

number of standard deviations below the mean for young, healthy person

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

who is most at risk for osteoporosis and why?

A

women, because 20% bone mass loss during menopause due to decreased estrogen
men have greater bone mass, so bones have more of a buffer
hereditary factors (polygenic, some people absorb less calcium) and lifestyle
caucasians and asians at higher risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

bone health team

A

players: osteoblasts, osteoclasts, collagen protein, Ca, P, Mg, F
coaches: vitamin D, parathyroid hormone and calcitonin
assistants: vitamins A, C and K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

acute functions of Ca

A

muscle contraction, nerve impulse transmission, blood clotting, immune function, blood pressure moderation

all acute functions are Ca as an ion in solution

must be maintained in precise homeostasis, physiological not diet based

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

chronic functions of Ca

A

mineral of bones and teeth
maintains bone turnover

low blood calcium robs bones of calcium to maintain blood homeostasis
causes stunting in children and osteoporosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

tetany

A

when blood Ca is low, causes muscle tremors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what causes rigor mortis?

A

When someone dies, ions are no longer pumped, Ca binds myosin and causes muscle contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

low blood calcium pathway

A

low blood calcium triggers parathyroid gland releases PTH (parathyroid hormone) which targets the kidneys and bones to release Ca into the blood

Kidneys activate calcitriol

Calcitriol signals kidneys to reabsorb more Ca from urine, increase Ca release from bone into blood, and increase absorption of Ca in the SI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

high blood calcium pathway

A

high blood calcium triggers thyroid gland to produce calcitonin

Calcitonin signals osteoblasts to reuptake calcium into the bones and build bone

22
Q

why is the RDA difficult to set for Ca?

why is the RDA for pregnant and lactating women the same as the adult RDA?

A
  • genetics affect peak bone density
  • dietary intake doesn’t affect the short term affects as much
  • pregnant women’s RDA is still 1000mg because hormone changes during pregnancy increase bioavailability during pregnancy and lactation
23
Q

percent of people that meet the RDA for calcium

A

90% of people consume 1000mg or less
10% consume the RDA

24
Q

Good sources of Ca

A

milk, yogurt, cheddar, tofu set with Ca, sardines
bok choy and broccoli are ok sources but well absorbed

25
Q

Calcium absorption is increased by
Calcium absorption is decreased by

A

anabolic hormones, gastric acid, vitamin D, low phosphate intake

aging, low stomach acid, vitamin D deficiency, high phosphate intake, high insoluble fiber intake, high phytate/oxalate intake

26
Q

bioavailability definition

A

degree to which a particular nutrient from a food source can be utilized

27
Q

Foods that decrease Ca bioavailability
why is spinach a poor source of Ca?

A

insoluble fiber binds cations
phytates: legumes, nuts and cereals
oxalates: spinach, beets, celery, eggplant, okra, berries, nuts, tea and cocoa

spinach is high in Ca but also high in oxalates, so only 5% bioavailability, whereas broccoli is 50% bioavailable

28
Q

who should take a Ca supplement?

type of supplement recommended

A

those at risk for low Ca intake like lactose intolerance, vegan or milk allergy
amino acid chelates ($$), Ca-based antacids, calcium citrate/gluconate/malate/carbonate, Ca chews

dolomite/bone meal not recommended due to contamination
multi-minerals can decrease absorption

29
Q

UL for Ca
side effects of toxicity

A

UL is 2500mg
milk alkali syndrome - metabolic alkalosis and renal failure
compromised iron and other mineral status
kidney stones
vitamin D toxicity and increased serum Ca if also supplementing vitamin D
contaminants from bone meal supplements

30
Q

Vitamin D synthesis

A

cholecalciferol synthesized from cholesterol from 10-15 minutes of summer sun on hands and face (UVB rays)

decreases with age, dark skin, latitude and winter

31
Q

Foods high in vitamin D

A

fatty fish, egg yolks, liver, fortified milk

32
Q

Vitamin D pathway

A

Provitamin 7-dehydrocholesterol made in the liver from cholesterol
In the skin, ultraviolet light converts 7-dehydrocholesterol into previtamin D3, which is then converted into D3
D3 (calciferol animal food sources), D2 (ergo calciferol, plant sources) from diet
In the liver D3 is hydroxylated into 25-hydroxy vitamin D3 (calcidiol)
In the kidneys D3 is hydroxylated again into 1,25-dihydroxy vitamin D3 (calcitriol) which is the active form

33
Q

which form of vitamin D can be stored?

A

calcidiol (the one made in the liver)

34
Q

Functions of vitamin D

A

required for calcium and phosphorus absorption
regulates blood Ca
stimulates osteoclasts
stimulates bone calcification
immunity and cell differentiation
*see calcium pathway

35
Q

vitamin D hormone and vitamin functions

A

hormone: travels in the blood to be activated in the liver and kidneys, acts on target tissues bone, kidney and intestines, increases Ca availability for bone mineralization and remodeling

vitamin: it is essential in the diet, with deficiency symptoms develop, it performs a specific function, we can’t synthesize as much as we need

36
Q

RDA vitamin D

A

assumes inadequate sun exposure
15ug/day or 600 IU per day under 70 years old
Above 70 is 20ug/800 IU

37
Q

vitamin D toxicity side effects

A

cannot occur from skin synthesis, only excess supplements/fish oil
hypercalcemia - high blood calcium
leads to calcification of soft tissues, disability and death can occur
UL is 100ug/day (4000 IU)

38
Q

reasons for high vitamin D deficiency in Canada

A

winter, reliance on fortification, pregnant milk restricted intake, sunscreen recommendations

39
Q

Osteomalacia

A

vitamin D deficiency in adults, intake below 2.5 ug/day
leads to decreased Ca absorption, loss of bone matrix and defective mineralization
decreased bone remodeling and softening of bone
bone pain and hip fracture risk

40
Q

Rickets

A

vitamin D deficiency in children
growing bones don’t mineralize properly
softening of bones leads to bowed legs, stunting and teeth problems
prevalence decreased with milk fortification, increasing again due to strictly breastfed babies

41
Q

Why should babies receive vitamin D supplementation while breastfeeding?

A

transfer in milk is regulated so it won’t improve child’s uptake if the mother supplements

42
Q

Phosphorus function in bone

A

with Ca forms hydroxyapatite mineral of bone
high intake decreases Ca uptake due to competition
typical intake is higher than RDA

43
Q

Magnesium function in bone

A

bone structure and regulation of mineralization
vitamin D metabolism
ATP synthesis
other: blood clotting, muscle contraction (opposite of Ca), blood pressure regulation

44
Q

vitamin K function in bone

A

co-enzyme for post-translational modification of bone proteins
deficiency results in poorly bound minerals

45
Q

vitamin A function in bone

A

bone remodeling
osteoclast activity

46
Q

vitamin C function in bone

A

cofactor for collagen synthesis (organic matrix)

47
Q

best way to prevent osteoporosis

A

maximizing peak bone mass increases time it takes to get below fracture risk threshold

48
Q

rate of bone loss per year after 20s to 30s
how to increase peak bone mass

A

1-2% per year, with increased losses during menopause for women
diet and exercise before the age of 20
after 20, diet, exercise and drugs can slow decline but can’t flatten it

49
Q

risk factors for osteoporosis
protective factors for osteoporosis

A

older age, low BMI, caucasian, asian or hispanic, cigarettes, excessive alcohol, glucocorticoids, anticonvulsants, high P, Na and protein intake

younger age, high BMI, African American, weight bearing exercise, diuretics, estrogen therapy, good lifetime diet

50
Q

how do smoking and alcohol increase risk of osteoporosis?

A

smoking - associated with low BMI, early menopause, low postmenopausal estrogen, decreased blood flow to bone

alcohol - increased Ca excretion, associated with lower dairy intake, toxic to osteoblasts

NUTR 207 (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions