Introduction to electrolyte balance DSA

Question 1

Normal K+ range

Answer 1

3.5-5 mEq/L

Question 2

How much K+ in the body?

Answer 2

3500 mEq K+

Question 3

K+ distribution in 70 kg human
IC
EC

Answer 3

IC - 98%
-> 80% muscle cells
-> 20% other cells
EC - 2%

Question 4

Hypokalemia level and causes (4)

Answer 4

[K+] < 3.7
Vomiting/diarrhea
Insulin excess
Deficiency
Alkalosis

Question 5

Hyperkalemia level and causes (2)

Answer 5

[K+] > 5.2
Excessive intake
Shifts from ICF to ECF

Question 6

Pseudohyperkalemia and cause (1)

Answer 6

Artificially high [K+] due to lysis of RBCs while blood is drawn.
Erythrocyte lysis.

Question 7

What is hypokalemia’s effect on RMP

Answer 7

Shifts more negative (decreases)

Question 8

What is hyperkalemia’s effect on RMP

Answer 8

Shifts closer to threshold (increases)

Question 9

Hyperpolarization leads to:

Answer 9

Bradycardia

Question 10

Hypopolarization leads to:

Answer 10

Tachycardia

Question 11

Ca++ daily needs

Answer 11

About 1000 mg/day

Question 12

Which groups are at highest risk for for Ca++ deficiency? (4)

Answer 12

Adolescents
Post menopausal women
Vegeterians
Lactose intolerant

Question 13

Hypocalcemia’s impact on neuromuscular excitability

Answer 13

Increases neuromuscular excitability

Question 14

Hypercalcemia’s impact on neuromuscular excitability

Answer 14

Decreased neuromuscular excitability

Question 15

What regulates Ca++ levels? (3)

Answer 15

PTH
Calcitrol
Calcitonin

Question 16

Daily required intake of Phosphorus

Answer 16

About 1500 mg phosphorus

Question 17

Where does Phosphate exists in the body (3)

Answer 17

85% bone
14% cells
1% serum

Question 18

4 regulators of phosphate metabolism

Answer 18

Dietary phosphate intake/absorption.
Calcitriol (increases resorption form bone and intestines)
PTH (resorption from bone and indirectly acivates intestinal absorption via calcitriol production).
Renal tubular reabsorption of phosphorus.

Question 19

Mg++ overview

Answer 19

50% in bone
49% in ICF
1% in ECF
Associated w/ migraine, depression, epilepsy, arrhythmias, etc.