Regulation of K, Ca, PO, Mg - McCormick

Question 1

Normal range of potassium?

Answer 1

3.5 - 5 mEq/l

Question 2

Extracellular K effects?

Answer 2

Resting membrane potential and excitability of muscle and nerve tissue

Question 3

How does low K effect resting membrane potential?

Answer 3

It is lower, so it takes more work to get it to threshold

High - potential is higher than normal

Question 4

Low K effects on EKG?

Answer 4

Low T wave

High U wave

Question 5

High K effects on EKG?

Answer 5

High T wave

Prolonged PR interval

Question 6

What is a huge list of things that can move K from ICF to ECF?

Answer 6

Hypokalemia
Acidemia
Hyperosmolality
Ischemia - cell damage
Heavy exercise

Question 7

List of things that can move K from ECF to ICF?

Answer 7

Hyperkalemia
Alkemia
B-adrenergic agonists
Insulin

Question 8

What cell exerts physiological control over potassium concentration?

Answer 8

Principal cells in collecting duct

Question 9

5 Factors affect K secretion in CD?

Answer 9

Extracellular K conc
Na reabsorption - negative luminal voltage attracts K
Luminal fluid flow rate - dilution of secreted K
Extracellular pH - K and H exchange across cell membranes
Aldosterone - K secretion in CD