Electrolytes Part 2 (Magnesium & Bicarbonate) Flashcards
(86 cards)
1
Q
Intracellular cation
A
MAGNESIUM
2
Q
2nd most abundant cation in the CELL
A
MAGNESIUM
3
Q
What is the 1st abundant cation in the CELL
A
Potassium
4
Q
4th most abundant cation
A
MAGNESIUM
5
Q
Rank Na, K, Ca, and Mg based on their abundance as a cation
1st - ____
2nd - ___
3rd - ___
4th - ____
A
1st - Na+
2nd - Ca2+
3rd - K+
4th - Mg2+
6
Q
How many magnesium are distributed in the bones?
A
53%
7
Q
How many magnesium are distributed in the muscles?
A
46%
8
Q
How many magnesium are distributed in the serum and RBC?
A
1%
9
Q
What are the Functions of Magnesium
A
-Maintenance of DNA, RNA, and Ribosomes structures
-CHO, CHONs and Lipid synthesis
-Neuromuscular transmission
-Enzyme cofactor (Activator)
-Regulated movement of K+ across myocardium
10
Q
Reference values of Magnesium
A
1.26-2.10 mg/dL
11
Q
What are the three forms of magnesium
A
- Free Mg2+ (Ionized form)
- Protein-bound Mg2+
- Ion-complexed Mg2+
12
Q
Free Mg2+ form
A
Ionized form
13
Q
Free Mg2+ (Ionized form) %?
A
55%
14
Q
physiologically active form of magnesium
A
Free Mg2+ (Ionized form)
15
Q
Protein-bound Mg2+ %?
A
30%
16
Q
Example of Protein-bound Mg2+
A
Albumin
17
Q
Ion-complexed Mg2+ %?
A
15%
18
Q
Example of Ion-complexed Mg2+
A
PO4- , citrate
19
Q
Three regulators of Magnesium
A
- Kidneys
- Parathyroid Hormone
- Aldosterone and Thyroxine (T4)
20
Q
principal regulator of magnesium
A
kidney
21
Q
Renal Threshold in kidney (Mg)
A
0.60-0.85 mmol/L
22
Q
reabsorbs 25-30% of filtered ionized Mg2+
A
PCT
23
Q
PCT reabsorbs ___ of filtered ionized Mg2+
A
25-30%
24
Q
reabsorbs 50-60% of filtered Mg2+
A
Ascending Loop of Henle
25
Ascending Loop of Henle reabsorbs ____ of filtered Mg2+
50-60%
26
reabsorbs 2-5% of filtered Mg2+
DCT
27
DCT reabsorbs ___ of filtered Mg2
2-5%
28
↑Mg2+ by increasing renal and intestinal reabsorption of Mg2+
Parathyroid Hormone
29
↓Mg2+ by increasing renal excretion of Mg2+
Aldosterone and Thyroxine (T4)
30
↓plasma Mg2+
HYPOMAGNESEMIA
31
Causes of hypomagnesemia
-Diarrhea and Pancreatitis
-Malabsorption
-Hyperparathyroidism
-Renal Loss
-Diabetes Mellitus
-Malnutrition
32
T/F: PTH causes excretion of Mg2+
T; PTH = ↑Ca2+ = causes excretion of Mg2+
33
↑plasma Mg2+
HYPERMAGNESEMIA
34
less frequent than hypomagnesemia
HYPERMAGNESEMIA
35
Causes of hypermagnesemia
Renal Failure
Antacids
Dehydration
Bone Cancer
Endocrine Disorder
Addison’s Disease
36
most common cause of HYPERMAGNESEMIA
Renal Failure
37
Specimen used in magnesium
Serum
Heparinized Plasma (Lithium heparin)
Urine
38
In magnesium, when using ____ as a specimen, it must be ____ with _____ to prevent ____ of Mg2+
Urine
acidified
Hydrochloric acid (HCl)
ppt
39
Variables in Mg
Hemolysis
Anticoagulants
40
T/F Hemolysis causes false decrease in Mg
F; false increase
41
Example of Anticoagulants that are considered variable in Mg
EDTA, oxalates, citrates
42
Why anticoagulants EDTA, oxalates, citrates considered as variables?
bec they bind Mg2+ causing false decrease
43
3 lab methods under Mg
Colorimetric Method
Dye-Lake Method
Atomic Absorption Spectrophotometry
44
4 examples of colorimetric method in Mg
Calmagite Method
Formazan Dye Method
Methylthymol Blue Method
O-cresolphthalein complexone
45
(+) reddish-violet complex (532 nm)
Calmagite Method
46
Calmagite Method forms what complex and measured at what wavelength
(+) reddish-violet complex
532 nm)
47
(+) blue-colored complex
Formazan Dye Method
48
formazan Dye Method complex and wavelegth
(+) blue-colored complex (660 nm)
49
(+) colored complex
Methylthymol Blue Method
50
Methylthymol Blue Method complex and wavelength
(+) colored complex (600 nm)
51
also used for calcium measurement
O-cresolphthalein complexone
52
O-cresolphthalein complexone measured at what wavelength
570 nm
53
Uses Titan Yellow Dye
Dye-Lake Method
54
Dye-Lake Method aka
Clayton Yellow or Thiazole Yellow
55
Dye-Lake Method: end product and wavelength
Yellow-colored complex
(570-590 nm)
56
2nd most abundant anion in the ECF or plasma
BICARBONATE
57
Function of Bicarbonate
-major component of blood buffering system (Bicarbonate-Carbonic Acid Buffer)
-90% of total CO2 in the blood at physiologic pH
-Buffers excess hydrogen ion by combining with acid
58
BICARBONATE FUNX
____ of total CO2 in the blood at physiologic pH
90%
59
When bicarbonate reach the ___ it will be split into ___ and ___ and will be eliminated by ____
LUNGS
H,O
CO2
EXHALING
60
Reference Values of bicarbonate
23-29 mmol/L (venous serum/plasma)
61
REGULATIONS:
Kidney
____: 85% HCO3- ____
DCT: _____ HCO3- _____
PCT; reabsorbed
15%; reabsorbed
62
REGULATIONS:
Kidney
PCT: ____ HCO3- reabsorbed
DCT: ____ HCO3- reabsorbed
85%
15%
63
Both PCT and DCT reabsorbs bicarbonate as ____
CO2
64
pH imbalance
Metabolic Acidosis
Metabolic Alkalosis
65
decreased plasma bicarbonate
Metabolic Acidosis:
66
HCO3- combines with H+ in the kidneys to produce CO2 which is exhaled by the lungs
Metabolic Acidosis:
67
increased plasma bicarbonate
Metabolic Alkalosis:
68
Usually seen in vomiting (loss of chloride from stomach)
Metabolic Alkalosis:
69
Specimen used in bicarbonate
Serum
Heparinized plasma
70
T/F: Specimen should be collected aerobically
F; anaerobically
71
The sample in Mg must always be capped. To prevent _____
CO2 escape
72
If sample is left uncapped = ______ in the bicarbonate
6 mmol/L per hour decrease
73
laboratory methods under bicarbonate
Enzymatic Method
Ion Selective Electrode
74
T/F The Enzymatic Method in bicarbonate is coupled enzyme
T
75
2enzymes under enzymatic method in bicarbonate
Phosphoenolpyruvate carboxylase
Malate dehydrogenase
76
membrane specific to ISE method in bicarbonate
Severinghaus electrode
77
Formula that doctors use to measure the difference between unmeasured cations and unmeasured anions
ANION GAP (AG)
78
Calculated by the concentration difference of measured cations (Na+, K+) and measured anions (Cl- , HCO3- )
ANION GAP (AG)
79
ANION GAP (AG) is Calculated by the concentration difference of measured cations (___, __) and measured anions (___ , ____ )
(Na+, K+)
(Cl- , HCO3- )
80
Measures increase in one or more unmeasured anions
ANION GAP (AG)
81
ANION GAP (AG) Measures increase in ___ or ____ unmeasured ___
one
more
anions
82
Used as quality control measure for analyzer
ANION GAP (AG)
83
Ref. range when using this formula
AG = Na – (Cl + HCO,)
7-16 mmol/L
84
Ref. range when using this formula
AG = (Na + K) – (Cl + HCO,)
10-20 mmol/L
85
What is the formula used if the reference range is
7-16 mmol/L
AG = Na – (Cl + HCO,)
86
What is the formula used if the reference range is
10-20 mmol/L
AG = (Na + K) – (Cl + HCO,)
