Electrolytes: Calcium

Question 1

________
-_____ is found in bone and teeth, _____ in blood
-Exists in blood in 3 forms:
*______________ - unbound and free, physiologically active as _____ of total calcium
*_____________ - bound to anions (____, _____, _____), ______ of total calcium
*________________ - bound to protein (________), _____ of total calcium
-involved in blood coagulation, ezyme activity, excitability of skeletal and cardiac muscle, and maintenance of BP.
-calcium is absorbed in ________ at ______ pH
-___________ decrease in albumin causes a _________ decrease in total calcium
-calcium levels are altered by blood pH
-_________ - lowers/decreases
-_________ - increases
-hormones:____, _______, ________,
-_________ - low serum calcium, high serum phosphorus
-_________ - low serum calcium, increased calcium and phosphorus in stool
-has a ___________________ relationship with phosphate

Answer 1

Calcium
99%, 1%
Free calcium, 45%
Complexed calcium, (bicarbonate, phosphate, lactate) 15%
Protein bound calcium (albumin) 40%
ileum, acidic
1g/dL, 0.8mg/dL
alkalosis
acidosis
PTH, calcitonin, Vit. D
Low PTH
Low Vit. D
inverse/reciprocal

Question 2

Functions of Calcium
* Contributor to structure of ______ and ______
* __________ - factor ____
* For proper ______________________
* __________ of enzymes
* ___________________________

Regulation
* __________________
-increase calcium in blood
-______________________ - mobilizes calcium from the bone
*________________
-decrease
-__________ - inhibits PTH and Vit D3
* ___________________
-__________ - increase calcium in intestines

Answer 2

bone and teeth
Coagualtion IV
contraction of heart muscles
Activator
Neurotransmission regulator

Bone resorption
PTH
Bone deposition
calcitonin
Intestinal resorption
vit D3

Question 3

Factors Affecting Plasma Calcium Levels
1. ___________________________
-increases intestinal absorption of calcium
-increases mobilization of calcium from bones
-increases reabsorption in kidneys
2. ____________________________
-conserves calcium by increasing reabsorption in kidneys
-increases by mobilizing bone calcium
-activates bone resorption
-suppresses urinary loss of calcium
-stimulates conversion of inactive Vit D to active D3
3. ______________
-thyroid hormone secreted by _______________ of thyroid gland
-inhibits PTH and Vit D3 - hypocalcemic hormone
-inhibits bone resorption
-promotes urinary excretion of calcium

Answer 3

1,25 Dihydroxycholecalciferol [1,25-(OH)2-D3)
Parathyroid Hormone (PTH)
Calcitonin
parafollicular C cells

Question 4

__________________________ - most common parathyroid hormone mediated hypercalcemia
_______________________- most common non-parathyroid hormone mediated hypercalcemia

Answer 4

Primary hyperparathyroidism
Malignancy associated

Question 5

Specimen Considerations and Patient Preparation
* _____,______,____________ sample may be used
* ______________, Do not use ______
* 24-hour urine calcium –> acidified using __________
o ______ HCL per ______ urine (__:____)
* Acids that are subject to interference with magnesium –> removed by adding ___________________

Answer 5

serum, plasma, 24-hour urine
Lithium heparin, EDTA
6M HCl
1mL:100 mL
8-hydroxyquinoline

Question 6

Methodologies
* _____________________ (___________________)
-calcium chelator
-produces a __________ complex at ________nm
-_________________ binds to magnesium which may interfere
-_______ - to reduce turbidity of lipemic serum and increase intensity of calcium dye complex
-_______ - decrease absorbance of blank

• Asenazo III (______________)
• __________
• __________________
• _______________________________________
  -calcium compounds in a flame dissociates into free calcium atoms
  -free atoms absorb light of a characteristic wavelength
  -__________- used to bind phosphate and cause falsely low result
• _________________________
• _______________________________
  -classic methods that measures ____________ as the end product
  -critical points:
  -_________ calcium oxalate ppt
  -_________ of oxalic acid with potassium manganese at _______
• ___________________________________
  -precipitation of calcium with chlororanilic acid
• __________________
  -done by removing calcium by EDTA

Answer 6

Orthocresolphthalein complexone (Hitachi and Dimension)
-reddish, 570-578 nm
-8-hydroxyquinoline
-urea
-ethanol

• Asenazo III (Vitro and Synchron)
• Alizarin
• Methylthymol blue
• Atomic absorption spectromphotometry
  -lanthanum
• Ion-selective electrode
• Clark Collip precipitation method
  -oxalic acid
  -critical points:
  -washing
  -titration at 70°C
• Ferro Ham chloroanilic acid precipitation method
• Compleximetric

Question 7

Values to Remember
Reference Values
* Total Calcium
o Child: __________________
o Adult: __________________

• Ionized Calcium
  o Child: __________________
  o Adult: __________________
• 24-hour Urine
  o ___________________

Conversion Factor
* mg/dL to mmol/L = _____

Answer 7

2.20-2.70 mmol/L
2.15-2.50 mmol/L

1.20-1.38 mmol/L
1.16-1.32 mmol/L

2.50-7.50 mmol/day

0.25