Electrolytes: Part 2 (Calcium & Phosphate) Flashcards
(168 cards)
1
Q
Most abundant cation in the body
A
Calcium
2
Q
Calcium is present almost exclusively in ______ (____________________________)
A
plasma
(Extracellular Fluid Ca2+)
3
Q
Distribution
___ - Bones
___ - Blood (plasma) and other ECF
A
99%
1%
4
Q
Blood Ca2+ (intravascular) is
______________ higher than other ECF
(interstitial)
A
5,000-10,000
5
Q
Absorption:__________ (________)
A
duodenum
acidic pH
6
Q
Enumerate the functions of Calcium
A
- Blood coagulation (especially ionized Ca2+ ),
enzyme activity - Skeletal and Cardiac muscle excitability
- Maintenance of Blood pressure
7
Q
Forms of Calcium
A
- Ionized Calcium/Free Calcium
- Protein-bound Calcium
- Complexed with anions
8
Q
How many percent is Ionized Calcium/Free Calcium?
A
50%
9
Q
How many percent is Protein-bound Calcium
A
40%
10
Q
How many percent is Complexed with anions?
A
10%
11
Q
Sensitive and specific marker for calcium
disorders
A
Ionized Calcium/Free Calcium
12
Q
Ionized Calcium/Free Calcium is not effected by ________ level
A
Albumin
13
Q
T/F: Ionized Calcium/Free Calcium is pH independent
A
FALSE; pH dependent
14
Q
________ pH: Ca2+ will be displaced from
albumin ((high/low)) free Ca2+)
A
Acidic
high
15
Q
_________ pH: Ca2+ binds with albumin ((high/low))
free Ca2+)
A
Alkaline
low
16
Q
Most active form and most abundant
A
Ionized Calcium/Free Calcium
17
Q
Freely circulating calcium:
A
Ionized Calcium/Free Calcium
18
Q
T/F: Ionized Calcium/Free Calcium is NOT bound to any substances
A
T
19
Q
T/F: Ionized Calcium/Free Calcium circulates as calcium itself
A
T
20
Q
Bound to _________; therefore, affected by __________
levels
A
Protein-bound Calcium
albumin
21
Q
↓Albumin = (low/high) Protein + Ca2+ affecting total Ca2+
A
low
22
Q
2nd most abundant
A
Protein-bound Calcium (40%)
23
Q
Example of Complexed with anions
A
● HCO3-, citrate, lactate
24
Q
Among the forms of calcium, only the __________ and _________________ are measured
A
Total Calcium
Ionized Calcium
25
Total Ca2+ = ___________ + Protein-bound +
Complexed with Anions
Ionized
26
only measures itself
Ionized Ca2+
27
REGULATION of Calcium
1. Hypercalcemic
2. Hypocalcemic
28
subs. that can ↑ Ca2+ levels
Hypercalcemic
29
enumerate the hypercalcemic substances
A. 1,25-Dihydroxycholecalciferol [1,25-(OH)2-D3]
B. Parathyroid Hormone (PTH)
30
1,25-Dihydroxycholecalciferol increases the _____________________, _________________ of Ca2+
intestinal absorption
renal reabsorption
31
Increased mobilization of Ca2+ from bones by
promoting bone __________ process.
1,25-Dihydroxycholecalciferol [1,25-(OH)2-D3]
resorption
32
Secreted by parathyroid gland
Parathyroid Hormone
33
Conserved Ca2+ by increasing ____________
Parathyroid Hormone
renal reabsorption
34
Increases level by mobilizing bone Ca2+
Parathyroid Hormone
35
How does Parathyroid Hormone increases level by mobilizing bone Ca2+
By activating bone resorption process
36
PTH activates ___________ (bone
macrophage) which destroys bone
tissues in which ____ of Ca2+ are found.
Therefore, it will liberate Ca2+ = (inc/dec) Ca2+
osteoclasts
99%
icn
37
Suppresses urinary loss of Ca2+
Parathyroid Hormone
38
Stimulates activation of inactive Vit. D
(______________) to active Vit. D3 (________)
Parathyroid Hormone
cholecalciferol
kidneys
39
Activation through the process of
______________ (addition of OH- in the liver on
the ____________ position) =_____________________
○ still inactive
hydroxylation
25th
25-hydroxycholecalciferol
40
Next hydroxylation happens in the ___________ on
the ______________ =
1,25-Dihydroxycholecalciferol (______________)
kidney
1st position
activated Vit. D3
41
subs. that can ↓ Ca2+ levels
Hypocalcemic
42
Enumerate hypocalcemic substance
A. Calcitonin
43
Secreted by the ____________________ of thyroid
glands
Calcitonin
parafollicular C cells
44
Inhibitor of ____ and ______
PTH
Vit. D3
45
Inhibits bone resorption
Calcitonin
46
bone destruction by osteoclast
bone resorption
47
Promotes urinary excretion of Ca2+
Calcitonin
48
Symptoms are usually neuromuscular excitability
(represent as tetany)
HYPOCALCEMIA
49
tetany is represented by:
muscle spasms,
paresthesia
50
What is pamamanhid
Paresthesia
51
HYPOCALCEMIA Only occurs: If Total Ca2+ _____ mmol/L (____mg/dL)
<1.88
<7.5
52
HYPOCALCEMIA 2 signs
Chvostek’s Sign
Trousseau's Sign
53
contraction of facial
muscles in response to tap
Chvostek’s Sign
54
uses BP cuff
Trousseau's Sign
55
BP cuff (inflated at _________ above the patient’s ____________ for 3-5 minutes)
20 mmHg
systolic
56
Trousseau's sign
Shows ______/___________ spasm
carpal/Carpopedal
57
Causes of Hypocalcemia
● Hypoparathyroidism
● Vitamin D deficiency
● Malabsorption
● Alkalosis
● Acute pancreatitis
● Hypomagnesemia
● Hypermagnesemia
● Hypoalbuminemia
58
hypercalcemic
Hypoparathyroidism
59
hypercalcemia
Vitamin D deficiency
60
alkaline in the blood; the calcium will
(bind/lyse) to albumin
Alkalosis
bind
61
In Alkalosis
(low/high) Ionized Ca2+
(low/high)Total Ca2+
low
high
62
_____ (secreted by pancreas) will enhance
intestinal binding of Ca2+
Acute pancreatitis
Lipase
63
↓Mg2+
Hypomagnesemia
64
Inhibits parathyroid hormone (PTH) secretion
Hypomagnesemia
65
Impairment of parathyroid hormone action
Hypomagnesemia
66
Vitamin __ resistance
Hypomagnesemia
D
67
↑Mg2+
Hypermagnesemia
68
Inhibits parathyroid hormone secretion
Hypermagnesemia
69
↓Albumin
Hypoalbuminemia
70
T/F: Hypoalbuminemia/ Ionized calcium is not affected. Only affects total calcium.
T
71
For every ↓1 g/dL ALB = ↓___mmol/L TC or
___ mg/dL TC
0.2
0.8
72
Causes of Hypercalcemia
● Hyperparathyroidism
● Hyperthyroidism
● Benign Familial Hypocalciuria
● Malignancy
● Acidosis
● Increased Vitamin D
● Thiazide diuretics
● Prolonged immobilization
73
main cause of hypercalcemia
Hyperparathyroidism
74
PTH excess
Hyperparathyroidism
75
mainly affect ionized Ca+ levels
Hyperparathyroidism
76
can also affect parathyroid glands because
of ______________
Hyperthyroidism
proximity
77
___________ does not have Ca+ (remains in the
blood)
Benign Familial Hypocalciuria
Urine
78
↑Ca+ (separates/adhere) with albumin
Acidosis
separates
79
↑ionized Ca+ , (inc/dec) total Ca+
Acidosis
↓
80
↑bone resorption
Prolonged immobilization
81
Specimun used in the laboratory analysis of Calcium
Serum
Heparinzed plasma
Timed urine sample
82
What type of heparinized plasma is acceptable in Calcium laboratory analysis
Lithium heparin
83
Never use EDTA or oxalates as they
__________ causing false decrease
chelate Ca2+
84
Timed-urine sample must be __________
must be acidified
85
How to acidify urine sample:
Addition of ________ of ___________ per
________ of urine
1mL
6 mol/L HCl
100 mL
86
Considerations/Variables for Ionized Ca2+:
1. Sample must be collected anaerobically
(must not be exposed to air)
2. Use dry heparin anticoagulant (if plasma)
87
air exposure of blood causes the
release of _____
CO2
88
_______ blood = Ca2+ binds with
___________ = false (inc/dec) in ionized calcium
alkaline
albumin
↓
89
Alternative in Laboratory Analysis of Calcium Considerations
Serum tubes collected using
ETS
90
Clotted and centrifuge for ___ minutes
at RT
10
91
Laboratory methods for Calcium
A. Precipitation and Redox Titration
B. Ortho-Cresolpthalein Complexone Dyes
C. EDTA Titration Method
D. Ion Selective Electrode
E. Atomic Absorption Spectrophotometry
F. Flame Emission Photometry
92
2 types of Precipitation and Redox Titration
1. Clark Collip Precipitation
2. Ferro Ham Chloranilic Acid Precipitation
93
Clark Collip Precipitation End Product:
Oxalic acid
94
Clark Collip Precipitation End Product color:
Purple color
95
Ferro Ham Chloranilic Acid Precipitation end product:
Chloranilic acid
96
Ferro Ham Chloranilic Acid Precipitation end product end color
Purple color
97
Colorimetric method
Ortho-Cresolpthalein Complexone Dyes
98
Interference of Ortho-Cresolpthalein Complexone Dyes
Mg2+
99
the interference Mg2+ causes false (inc/dec)
Increase
100
Mg2+ inhibitor/chelators is added
(__________________)
8-hydroxyquinoline
101
Dye in Ortho-Cresolpthalein Complexone Dyes
Arzeno III
102
EDTA Titration Method example
Bachara, Dawer and Sobel
103
Liquid membrane
Ion Selective Electrode
104
reference method for calcium
Atomic Absorption Spectrophotometry
105
Almost all phosphorus are combined with O2
forming __________
phosphate
106
Predominant intracellular anion
Phosphate
107
● PO4 is inversely related to _______
Ca2+
108
Phosphate distribution
→ ____ - bones
→ ____- soft tissues
→ ____ - plasma
80%
20%
<1%
109
Adsorption in phosphates
Jejunum (in diet)
110
Function of Phosphates
→ Insulin-mediated glucose entry in the cell
→ DNA and RNA structures
→ Energy reservoir
→ Promotes hemoglobin affinity to oxygen
→ Coenzyme
111
Process present in Insulin-mediated glucose entry in the cell
phosphorylation
112
Phosphates present in DNA and RNA structures
phosphodiesters
113
Phosphates present in Energy reservoir
Adenosine triphosphate (ATP)
114
Phosphate present in Promotes hemoglobin affinity to oxygen
2,3-Biphosphoglyceric acid
115
Phosphates present in Coenzyme
phosphoric/pyrophosphoric acid
116
Total phosphate in blood:
12 mg/dL
117
Phosphates may exist as
Organic Phosphate
Inorganic Phosphate
118
Organic phosphate how much
8-9 mg/dL
119
Inorganic phosphate how much
3-4 mg/dL
120
principal intracellular anion
Organic Phosphate
121
part of blood buffer
Inorganic phosphate
122
can maintain blood pH
Inorganic phosphate
123
the ONLY type measured in the
laboratory
Inorganic phosphate
124
Forms of Phosphorus
→ Free/Unbound
→ Complexed with ions
→ Protein-bound
125
Percent of free/unbound phosphorus
55%
126
Percent of phosphorus complexed with ions
35%
127
Percent of protein-bound phosphorus
10%
128
Regulation of phosphate:
A. Parathyroid hormone
B. Vitamin D
C. Growth hormone
129
(↓PO4-)
Parathyroid hormone
130
(↑PO4-)
Vitamin D
Growth hormone
131
Decreases phosphate by renal excretion
Parathyroid hormone
132
Increases _______________ and ______________ absorption of phosphate
Vitamin D
Intestinal and Renal
133
Increased phosphate renal reabsorption
Growth hormone
134
Decreased plasma phosphate concentration
HYPOPHOSPHATEMIA
135
Very critical for a patient
HYPOPHOSPHATEMIA
136
why is HYPOPHOSPHATEMIA very critical for a patient?
ATP relies on phosphate
137
(low/high) PO4- may lead to ATP depletion
low
138
Severe hypophosphatemia
<1.0 mg/dL
139
Causes of Hyphophosphatemia
1. Alcoholism
2. Vitamin D Deficiency
3. Renal Tubular Acidosis
4. Hyperparathyroidism
5. Rickets
6. Fanconi Syndrome
7. Transcellular shift
140
most common of hypophosphatemia
Alcoholism
141
Alcoholism
→ most common of hypophosphatemia bec. it
impairs absorption of phosphate in the
_________
intestine
142
CAUSES
↑PO4-
Vitamin D Deficiency
143
CAUSES
PTH (inc/dec)PO4- (by inc. renal excretion)
dec
144
major cause of hypophosphatemia
Transcellular shift
145
PO4- in the blood that enters the cell = (inc/dec) PO4- in plasma
Transcellular shift
dec
146
at risk are patients with Acute/Chronic Renal
Failure
HYPERPHOSPHATEMIA
147
Causes of HYPERPHOSPHATEMIA
1. Renal Disease
2. Hypoparathyroidism
3. Excess Vitamin D
4. Acromegaly
5. Lymphoblastic Leukemia
148
Leading cause of Hyperphosphatemia
Renal Disease
149
increased GH that (inc/dec) PO4-
Acromegaly
inc
150
_____________ (immature lymphocytes) have
_____ more phosphate compared to
lymphocytes
Lymphoblastic Leukemia
lymphoblasts
4x
151
Specimen used in the laboratory analysis of Phosphate
Serum
Heparinized plasma
24hr urine
152
Variables in the laboratory analysis of phosphates
Hemolysis
Circadian Rhythm
Other anticoagulants
153
Hemolysis in laboratory analysis of phosphates causes false (inc/dec)
Increase
154
Hemolysis is false increase due to higher phosphate in ____ compared to _______
RBC
plasma
155
natural changes that occurs in the body within 24 hrs
Circadian Rhythm
156
_______ - highest phosphate
Late morning
157
__________ - lowest phosphate
Evening
158
Other anticoagulants that is a variable in the laboratory analysis of Phosphates that may interfere with the methods
EDTA
Citrate,
Oxalate
159
Laboratory method for phosphates
1. Fiske Subbarow Method (aka Ammonium
Molybdate Method)
160
Most commonly used method for measuring
inorganic phosphate
Fiske Subbarow Method (aka Ammonium
Molybdate Method)
161
Principle:
Phosphorus + ammonium molybdate --> __________________________________ (340 nm)
ammonium phosphomolybdate
162
Principle
ammonium phosphomolybdate + pictol -->>>> _____________________ (600 nm)
molybdenum blue
163
colorless end product ; measured at
340 nm
Ammonium phosphomolybdate:
164
what region is Ammonium phosphomolybdate:
UV region
165
most accurate method
Ammonium phosphomolybdate
166
Alternative method: If UV spectro is not
available, ______ can be added
reducing agent
167
The addition of RA, will facilitate the
formation of __________________
measured at 600 nm (_______ region)
molybdenum blue
visible
168
Disadvantage:
___________ pH = reduction of molybdenum blue (false (inc/dec)))
Alkaline
decrease
