Calcium Flashcards

1
Q

____ IS THE MOST ABUNDANT MINERAL IN THE BODY

A

CALCIUM!

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2
Q

about 99% of calcium in the body is found

A

in the bone and teeth

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3
Q

sources

A
dairy
seafood
veggies
figs
black strap molasses
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4
Q

_____ is the most potent inhibitor of calcium absorption and is found at high concentration in spincach and rhybabrb

A

oxalate (oxalic acid)

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5
Q

calcium is present in foods as relatively insoluble _____

A

salts

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6
Q

calcium can be solubilized at an _____pH

A

acidic

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7
Q

absorption of calcium occurs primarily in the SI and

A

two routes

  1. duo and prox jeju
  2. jeju and ile
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8
Q
  1. absorption through the duodenum and proximal jejunum
A
cellular
active transport (req ATP)
saturable
involves calcium binding protein
stimulated by 1,25OH and low Ca levels
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9
Q
  1. absorption through the jejunum and ileum
A
paracellular
passive diffusion- requires no energy
unsaturable
requires no carrier
stim- when high [ ] of Ca intracell and in lumen
stim by FOS
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10
Q

factors that enhance calcium absorption

A
growth pregnancy lactation
vitamin d
simple sugars
protein
food
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11
Q

factors that inhibit calcium absorption

A
oxalate
phytate
fiber
other divalent cations and minerals
fal maldigestion
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12
Q

Calcium is transported across the cytoplasm of the enterocyte bound to

A

CBP

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13
Q

calcium is transported from enterocyte into extracellular fluid by

A

Ca/Na ATPase

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14
Q

calcium is transported in the blood in three forms

A

free
proteins (albumin)
sulfate, phosphate, citrate

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15
Q

calcium levels in the___ and ___ must be maintained within a very narrow concentration range for normal physiological functioning

A

blood and extracellular fluid

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16
Q

extracellular calcium concentration or regulated by

A

PTH
calcitriol
calcitonin

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17
Q

___ plasma calcium levels stimulate PTH secretion and inhibit calcitonin secretion

A

low

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18
Q

PTH and calcitriol _____ plasma calcium

A

increase

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19
Q

PTH increases renal synth of calcitriol from ___

A

25-OH vit d

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20
Q

PTH and calcitriol increases renal tubular reabsorption of

A

calcium

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21
Q

calcitriol enhances intestinal ____absorption

A

calcium

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22
Q

PTH and calcitriol stimulate _____ activity

A

osteoclast

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23
Q

high plasma calcium levels stimulate ____ secretion, which _____ serum calcium levels

A

calcitonin, lower

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24
Q

calcitonin secretion inhibits _____activity which stimulates osteoblasts

A

osteoclasts

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25
Q

calcitonin inhibits ____ production which decreases calcium absorption and increases calcium excretion in the urine

A

calcitriol

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26
Q

Serum calcium

A

incr PTH
incr calcitriol
decr calcitonin

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27
Q

bone calcium

A

decr PTH
dec calcitriol
incr calcionin

28
Q

renal calcium reabsorption

A

incre PTH
incr calcitriol
decr calcitonin

29
Q

intestinal calcium absorption

A

no effect on PTH
incr calcitriol
no effect on calcitonin

30
Q

low free calcium concentration are maintained within the ____

A

cytoplasm

31
Q

calcium is needed in higher concentrations where

A

in the cells to carry out fxns

32
Q

cell activation by ___, ___ or ___ results in increased calcium entering the cell by diffusion or by the opening of calcium channels

A

depolarization
neurotransmitters
hormones

33
Q

calcium is a major structural element in ___ and ___

A

bone and teeth

34
Q

the mineral component of bone consists mainly of___

A

hydroxyapatite

35
Q

_____ begin remodeling by dissolving or resorbing bone

A

osteoclats

36
Q

_____ synthesize new bone to replace the bone that was resorbed

A

osteoblasts

37
Q

during normal growth, bone formation_____ bone resportion

A

exceeds

38
Q

_______ may result when bone resorption chronically exceeds formation

A

osteoporosis

39
Q

functions of calcium

A

bone mineralization
nerve conduction
muscle contraction
coagulation

40
Q

calcium entering the neuron triggers the release of _____ signalling muscle contraction

A

acetyl choline

41
Q

when mm fiber receives nerve impulse to contract, calcium channels in the cell membrane _____ to allow a small number of calcium ions into the muscle cell

A

open

42
Q

the binding of calcium is required for the activation of several ______dependent clotting factors in the coagulation cascade

A

vitamin k

43
Q

most of the calcium in the blood is filtered and reabsorbed by the ____

A

kidney

44
Q

calcium is primarily excreted from the body in the

A

urine and feces (also perspiration a bit)

45
Q

Deficiency of calcium results in

A

hypocalcemia

osteoporosis

46
Q

T or F calcium deficiency is most common in women over the age of 12, and the elderly

A

true

47
Q

hypocalcemia usually implies____ and is rarely due to low dietary calcim intake

A

parathyroid function

48
Q

other causes of hypocalcemia

A

chronic kidney failure
vitamin d deficiency
low blood magnesium
(usually caused by alcoholism)

49
Q

symptoms of hypocalcemia

A

tetany and muscle spasm, muscle pain ad parashtesias

50
Q

low seruum calcium levels cause what

A

muscle spasms

51
Q

why does low serum calcium levels cause muscle spasm

A

because the permeability of neuronal membranes to sodium ions increases, causing a progressive depolarization, which increases the possibility of generating action potentials

52
Q

tests for hypocalcemia

A

chvosteks sign

trousseaus sign

53
Q

what is chvosteks sign

A

abnormal spasm of facial muscle elicited by a light taps on the cheek

54
Q

what is trousseaus sign

A

the wrist and metacarpophalangeal joints flex, the DIP and PIP joints extend and the fingers adduct

55
Q

how do you elicit a trousseaus sign

A

a blood pressure cuff is placed around the arm and inflated for three minutes. this will occlude the artery and in absence of flow the patients hypocalcemia and neuromuscular irritability will induce spasm

56
Q

what is osteoporosis

A

increase bone fragility and fracture risk

57
Q

chronically ___ calcium intake may result in a failure to attain optimal bone mass

A

low

58
Q

once peak bone mass is acheived, inadequate __ intake may contribute to osteoporosis

A

calcium

59
Q

clinical indications for calcium supplementation

A

osteoporosis

kidney stones

60
Q

_____resulting from the over consumption of calcium from FOOD has never been reported

A

hypercalcemia

61
Q

hypercalcemia has been reported with consumption of large quantities of ___-

A

calcium supplements

62
Q

symptoms of mild hypercalcemia include

A
loss of appetite
n/v
constipation
abd pain
dry mouth, thirst
freq urination
63
Q

sever hypercalcemia may result in

A

confusion
delerium
coma
death

64
Q

increase dietary calcium has been associated with a _____ risk of kidney stones

A

decreased

65
Q

high calcium may decrease the absorption of

A

non heme iron

zinc

66
Q

high calcium intake may decrease tissue levels of

A

mg

67
Q

high __ intake can increase calcium excretion in the urine

A

sodium