LEC5 - CALCIUM Flashcards
this electrolyte is present almost exclusively only in plasma
CALCIUM
It is the fifth most common element and the most prevalent
cation (extracellular) in the human body
CALCIUM
Majority of the calcium in the body is stored in the ___ 99%, few in the circulation 1%
bone
Ca2+ was essential for ___ contraction
myocardial
the electrolyte that is important in skeletal mineralization
CALCIUM
Neural transmission (involve in activities like
maintenance of compounds within the cell)
calcium
calcium is maximally absorbed in what part of GIT
duodenum at acidic pH
symptoms of severe hypocalcemia will appear when the total calcium is lower than
<7.5 mg/dl
it is involved in glandular synthesis and regulation of exocrine and endocrine glands vice versa (concentration of electrolytes is also being regulated by endocrine glands )
calcium
it preserves the cell membrane’s integrity and permeability particularly in terms of sodium and potassium exchange
calcium
it avoids cell destruction during the sodium and potassium exchange
calcium
what are the 3 hormones that affect calcium
parathyroid hormone, vitamin D, and calcitonin
calcitonin is secreted by what gland
thyroid gland
a hypocalcemic hormone as it inhibits PTH and VITAMIN D3
calcitonin
inhibits bone resorption and promotes urinary excretion
calcitonin
PTH is secreted by the
parathyroid gland
if the calcium level is balanced, do parathyroid gland will release PTH?
nope, it is only released if there’s an imbalance in calcium
PTH acts on 2 organs what are they
bones and kidney
what will happen to the PTH in bone
PTH stimulates the osteoclastic activity which in turn releases calcium ions and hydrogen phosphate
bone building cells
osteoblast
bone destroying cells
osteoclast
in regulation of calcium, specifically in the kidney, PTH promotes :
absorption of calcium
excretion of hydrogen phosphate
activation of renal 1-alpha-hydroxylase
relationship of calcium and PTH
directly
relationship of calcium and hydrogen phosphate
inversely proportional
inactive form of vitamin D that acts upon on instestine and kidney
circulating 25 OH vit D
how vitamin D works on intestine in regulation of Ca2+
vit D promotes intestinal absorption of calcium and hydrogen phosphate
how vitamin D works on kidney in regulation of Ca2+
Vitamin D promotes renal reabsorption of calcium and hydrogen phosphate
how vitamin D helps in calcium regulation
helps in reabsorption of calcium in intestine and kidney as well as the hydrogen phosphate
PTH secretion in blood is stimulated by a decrease in
ionized Ca2+, and conversely, PTH secretion is stopped by
an increase in ionized Ca2+.
correct?
yep
define ionized calcium
a free form calcium - no derivatives, just calcium alone, no compound added
is a sensitive and specific marker for calcium disorders
ionized calcium
PTH activates a process known as ____, in which activated osteoclasts break down
bone and subsequently release Ca2+ into the ECF
bone resorption
In the kidneys, PTH conserves Ca2+ by increasing
tubular reabsorption of Ca2+ ions.
correct?
correct
Vitamin D3, a _____, is obtained from the diet or exposure of skin to sunlight.
cholecalciferol
derivative of vitamin D
cholesterol - that is why Vitamin D3 is classified as a cholecalciferol
vitamin D3, a cholecalciferol
diet or exposure of skin to sunlight
vitamin D3 will be converted into ____
25 hydroxycholecalciferol: inactive ((25-OH-D3)
the vitamin D3 that was been converted into 25-OH-D3 will then be hydroxylated in the kidney to form
1,25-dihydroxycholecalciferol (1,25-[OH]2-D3)
active form
a form of vitamin D which will inititiate the absorption of calcium in the intestine
1,25-dihydroxycholecalciferol (1,25-[OH]2-D3)
an organ that regulates electrolytes
kidney
organ where the calcium is synthesized
liver
About ____% of Ca2+ in the body is part of bone
99
The remaining ___% of calcium is mostly in the blood and other
ECF
1
Free or ionized form (____%) circulates only as calcium
50
travels without any binding components “__”
Ionized calcium
calcium Bound to plasma protein (_____%) Albumin
40%
calcium
Complex form (___%) Bound to another anion electrolytes
such as bicarbonate, citrate or lactate
10
Increased calcium levels are seen in:
o Periods of rapid growth in children (Bone formation
and growth period)
o Pregnancy
o Lactation
Decreased calcium level is seen in
o Old age – brittle bones, geriatric stage
major stimulus of calcium absorption
Vitamin D
Increased calcium absorption happening in intestine
o Vitamin D (major stimulus of calcium absorption)
o Growth hormone
o Increased dietary protein
Decreased calcium absorption in intestine
o Formation of insoluble salts with phosphorus
o Phytic acid
o Dietary oxalate
o Fatty acids
o Cortisol
Increased urinary calcium excretion in kidney
o Hypercalcemia
o Phosphate deprivation
o Acidosis
o Glucocorticoid
Diminished urinary calcium excretion - kidney
o PTH
o Certain diuretics
o Vitamin D
It is a condition characterized by an increased serum
calcium level
HYPERCALCEMIA
__ is the main cause of
hypercalcemia
Primary hyperparathyroidism
HYPERCALCEMIA is associated with what symptoms
anorexia, nausea, vomiting,
constipation, hypotonia, depression & coma
if mild type of hypercalcemia, will there be some symptoms?
none, asymp
Moderate or severe Ca2+ elevations include
neurologic, GI,
and renal symptoms.
Neurologic symptoms for hypercalcemia may include
mild drowsiness or
weakness, depression, lethargy, and coma.
GI symptoms for hypercalcemia may include
constipation, nausea, vomiting,
anorexia, and peptic ulcer disease.
Hypercalcemia may cause renal symptoms of
.
nephrolithiasis and nephrocalcinosis
Hypercalciuria can result in what type of diabetes, which causes polyuria that results in hypovolemia
nephrogenic diabetes insipidus,
_____ can also cause symptoms of digitalis
toxicity.
Hypercalcemia
increased hydrogen ion, the body will ____ calcium
excrete
hypocalcemia is can be considered only as hypo if the Calcium is being below _______mmol/L
1.88
Severe hypocalcemia will eventually lead to ___
tetany
Severe hypocalcemia will eventually lead to tetany which is caused by what bacteria
clostridium tetani
hypocalcemia There can be what symptoms
neuromuscular irritability and cardiac
irregularities
primary hypoparathyroidism of hypocalcemia is primarily caused by
glandular aplasia, destruction, or removal of parathyroid hormone ghland
PTH gland has an actual production of hormone however the PTH produced are not working or responsing
pseudohypoparathyroidism
increase activity of intestinal lipase in pancreas causing intestinal binding of calcium
hypocalcemia - acute pancreatitis
as with major crush injury and muscle
damage, may cause hypocalcemia as a result of increased
PO4– release from cells, which bind to Ca2+ ions
Rhabdomyolysis
a method of calcium determination
Spectrophotometric analysis with the metallochromic
indicators
total calcium
the indicator for calcium that uses _____
which is more common and uses 8-hydroxyquinoline in
order to prevent the possible interference cause by magnesium
Orthocresolphthalein complexon
in total calcium,
___ are most widely
used indicators – colorimetric method
Arsenazo III
a total calcium method
with
ethylene diamine tetra acetic acid (EDTA) or ethylene
glycol tetra acetic acid (EGTA).
Titration of fluorescent calcium complex
considered as the reference method as calcium is
known to be a stable compound
Atomic Absorption Spectrophotometry (AAS)
why do Atomic Absorption Spectrophotometry (AAS) is not used anymore in calcium determination
expensive
(Redox Titration Method) of calcium
clark and collip method
methods for total calcium
Spectrophotometric (Orthocresolphthalein complexone (CPC and Arsenazo III)
Titration of fluorescent calcium complex
Atomic Absorption Spectrophotometry (AAS)
Clark and Collip Method (redox titration method)
method for ionized calcium and is most common in electrolyte analysise
ISE - Ion selective electrode
Ion-Selective Electrode (ISE) - membrane used is the __
electric cellophane membrane
Uses electrode same as with other
ISE method where the membrane of the
electrode binds with calcium ion ( electric Cellophane
membrane)
Ion-Selective Electrode (ISE) for Calcium
REFERENCE INTERVAL for calcium
Plasma/Serum:
o 8.8-10.3 mg/dL (2.20-2.58 mmol/L) total Calcium in adults
o 4.6-5.3 mg/dL (1.16-1.32 mmol/L) ionized
Calcium in adults
Urine:
o 300 mg/day (7.9 mmol/day) in normal adults
o 24h
the major net loss of calcium
urinary excretion
preferred anticoagulant for calcium
calcium titrated heparin
decreased pH of the reagent for calcium determination will result in __
liberation of calcium from albumin
prolonged contact of serum with cell clot will cause ___ to calcium
false decrease
prolonged tourniquet will cause ___ calcium
increase
relationship of plasma protein to calcium concentration
directly proportional, a decrease in plasma protein will cause a decrease in calcium level as well, kasi remember may protein bound na calcium for about 40%??
if di mo maalala, recall ka gurl
reference method for calcium determination
AAS - atomic absorption spectriphotometry
in colorimetric method for total calcium, we have 2 methods under, state the difference when it comes to pH of the solution/reagent
ortho-cresolpthalein complexone = alkaline ph
Mg interferes
arzenazo III dye = acidic solution
Mg does not interfere
citrate and hemolyzed sample interfere
causes of hypercalcemia
CHIMPS:
cancer
hyperthyroidism
Iatrogenic causes
Multiple myeloma
Hyperparathyroidism
Sarcoidosis
causes of hypocalcemia
CHARD
calcitonin
hypoparathyroidism
alkalosis
renal failure
D vitamin deficit
why acidosis causes hypercalcemia
acidosis promotes leaching of calcium from bones,
hydrogen ions which displace calcium from proteins, nafe-free ang calcium na pagala gala
why alkalosis causes hypocalcemia
alkalosis causes plasma proteins to have a negative charge that in turn binds more ionized calcium, konti nlanag pagala gala kaya hypocalcemia
alkalosis promotes deposition of calcium in bones
main cause of hypercalcemia
primary hyperparathyroidism
relationship of estrogen in Vitamin D
reduces formation of active Vitamin D
kaya ang buntis mataas ang calcium, kasi mataas ang estrogen nila
so kapag deficient, wala di maaactivate si vitamin D, no absorption of calcium
