exam 2: regulation of plasma calcium and phosphate Flashcards

1
Q

85% of the body’s PHOSPHATE is stored in _______, 14-15% in _____ and less than 1% in the _____

A

bones
cells
EC fluid

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2
Q

only .1% of total body calcium is in the ________. 1% is in _____ and ____ and the rest is store in _________

A

EC fluid
1% in cells
rest in bones

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3
Q

too low of calcium=

A

neuronal hyper-excitability (tetany)

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4
Q

too high of calcium=

A

neuronal depresion

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5
Q

control points for calcium and phosphate:

A
  1. absorption
  2. excretion
  3. temporary storage
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6
Q

control points for calcium and phosphate: (regulation)
1. absorption=
2. excretion=
3. temporary storage=

A
  1. absorption= via intestines
  2. excretion= via urine (both ca and phos) (feces ca only)
  3. temporary storage= via bones (hydroxyapatite)
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7
Q

carpal spasm due to

A

HYPOcalcemia

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8
Q

3 principle hormones that regulate plasma calcium and phosphate:

A
  1. parathyroid hormone (PTH)
  2. calcitriol
  3. calcitonin
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9
Q

PTH:

A

increases Ca
decreases phosphate

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10
Q

calcitriol:

A

increases ca
increases phosphate

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11
Q

calcitonin:

A

decreases ca
decreases PTH

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12
Q

what hormone is the primary hormone that enhances intestinal absorption of calcium and it also causes absorption of phosphate

A

calcitriol (vitamin D3)

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13
Q

releases Ca from bone, enhances renal reabsorption of calcium (kindeys), increases intestinal absorption of calcium (indirectly)= increase vitamin D production

A

PTH

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14
Q

in addition to PTH, bone resoprtion is stimulated by

A

cortisol and T3

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15
Q

how does PTH indirectly increase intestinal absorption of calcium

A

increasing vitamin D production

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16
Q

what two things stimulate bone matrix RESORPTION which INCREASEs plasma calcium

A

vitamin D3 aka calcitrol and parathyroid hormone PTH

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17
Q

excess vitamin D’s main effect is ___ ______ of calcium and phosphate

A

gut absorption

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18
Q

build bone matrix:
break down bone matrix:

A

build: osteoblasts
break down: osteoclasts

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19
Q

what binds to osteoclasts and activates them?

increase of these produced by osteoblasts and it lets them break down the hydroxyatite to increase plasma calcium and phosphate

A

RANKL

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20
Q

occurs when imbalance between bone formation and resoprtion

A

osteoporosis

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21
Q

risk factors for osteoporisis

A

vitamin D deficiency
inadequate calcium intake
estrogen deficiency
smoking
alcohol
reduced activity

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22
Q

lot of other things that activate osteoblasts that break down calcium (bone breakdown) break down hydroxyapatite

A

corticosteriods (cortisol)
prolactin
vitamin D3

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23
Q

calcitonin stimulates bone matrix ________ and inhibits ________= ____ in plasma calcium

A

deposition
inhibits osteoclasts
decrease in plasma calcium

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24
Q

vitamin D3 and PTH stimulate bone matrix____

A

resorption

25
Q

with calcitonin, there is increased production of:

which binds to RANKL so RANKL cannot bind to osteoclasts= apoptotic osteoclast

what does this:

A

increased production of OPG
estrogen, calcotonin

26
Q

treatments for osteoprosis

A

excerise
physical therapy
estrogen
calcium
vitamin D
bisphosphonates

27
Q

4 pea sized glands on POSTERIOR surface of thyroid gland

A

parathyroid glands and hormone

28
Q

PTH is secreted by:

A

chief cells

29
Q

PTH
increases ______ by
increasing _______,
decreasing __________,
and increasing _________-

A

increases: plasma calcium

by
increasing= intestinal absorption (indirectly by increasing vitamin D levels)
decreasing= renal excretion
increasing= bone resorption

30
Q

PTH decreases _________ by
increasing ________-

A

PTH decreases phosphate by increasing renal secretion/excretion and decreasing renal reabsorption

31
Q

decrease ECF ca2+ concentration would cause an ______ of PTH secretion hypertrophy of parathyroid gland due to=
pregnancy, rickets, lactation

A

increase rate of PTH secretion

32
Q

increase ECF Ca2+ concentration would lead to _____ activity of parathyroid gland and _____ size of parathyroid gland

A

decrease activity of parathyroid gland decrease size of it

33
Q

what would be the cause of increase ECF Ca2+ concentrations:

A

increased vitamin D intake
excess quanitities of calcium in the diet
bone resorption caused by factors other than PTH

34
Q

what would cause decrease ECF Ca2+ concentrations

A

pregnancy
rickets
lactation

35
Q

what indirectly increases intestinal calcium absorption in the intestines

A

vitamin D

36
Q

increase of PTH with kidney:
phosphate:

A

increase PTH

decrease in phosphate reabsorption
increase of phosphate renal secretion

leads to decrease in plasma phosphate

37
Q

increase of PTH with kidney.
calcium:

A

increase PTH

increase in calcium reabsorption
decrease in calcium renal secretion

leads to increase in plasma calcium (calcium back to normal levels)

38
Q

increase in PTH with bone:

A

leads to increase bone resorption
leads to increase in plasma calcium

39
Q

vitamin D3 can be stored in the ___ for several months

A

liver

40
Q

what activations the enzyme in the kidney that makes calcitriol

A

PTH

41
Q

what 3 things are necesary in making active form of vitamin D3

A

skin
liver
kidney

42
Q

the active form of vitamin D3 (calcitriol) increases the intestinal absorption of _____ in the intestines epithelium

A

calcium and phosphate

43
Q

main effect of vitamin D or calcitriol is:

A

absorption of Ca and Phosphate via intestines

44
Q

however, vitamin d or calcitriol by some effect can reduce excretion of:

by what:

and it can also lead to:

A

Calcium or phosphate by the kidneys

lead to bone deposition (indirectly by increasing level of calcium in the blood)

45
Q

what is not a major controller of Ca2+ in humans

A

calcitonin

46
Q

calcitonin is a peptide hormone secreted by

A

parafollicular cells (C cells) by the thyroid gland

47
Q

this is released in response to elevated levels of free plasma Ca

A

calcitonin

48
Q

calcitonin lowers plasma Ca by decreasing activity of:

A

osteoclasts this decreasing bone resorption (so bone deposition)

49
Q

excess PTH secretion due to parathyroid gland tumor

A

primary hyperparathyroidism

50
Q

Thyroid hormone produced in highest concentrations

A

T4

51
Q

thyroid hormone produces most of target cells actions of thyroid hormone

A

T3

52
Q

primary hyperparathyroidism causes extreme osteoclastic activity in bones causes:

A

cystic bone disease
(extreme bone break down)

53
Q

primary hyperparathyroidism.

  1. hypercalcemia leads to:
  2. low phophate due to:
  3. muscle weakness and easy fatigability
  4. osteoblastic activity also increased leading to high section of:
A
  1. hypercalcemia leads to: polyuria
  2. low phophate due to: increase renal excretion
  3. muscle weakness and easy fatigability
  4. osteoblastic activity also increased leading to high section of: ALP (alkaline phosphatase)
54
Q

high PTH levels occur as compensation for HYPOCALCEMIA not due to primary abnormality of parathyroid glands

A

secondary hyperparathyroidism

55
Q

hypercalcemia:
hypocalcemia:

A

hypercalcemia: primary hyperparathyroidism
hypocalcemia: secondary hyperparathyroidism

56
Q

causes of hypocalcemia: (secondary hyperparathyroidism-high PTH levels)

A

vitamin D deficiency
and
chronic renal disease- cannot synthesize Vitamin D3

57
Q

what leads to rickets in children and osteomalacia in adults and high PTH

A

vitamin D defiency

58
Q

less common
-results from accidental surgical parathyroid gland removal
-DECREASES CA levels

A

primary hypoparathyroidism

59
Q

hypocalcemia increases membrane Na permeability leading to neurmuscular excitability and muscle spasms and:

A

tetany (carpal spasm)