Physio: Kidney Solute Processing: Potassium, Calcium, Magnesium Flashcards Preview

Week 2 > Physio: Kidney Solute Processing: Potassium, Calcium, Magnesium > Flashcards

Flashcards in Physio: Kidney Solute Processing: Potassium, Calcium, Magnesium Deck (12):
1

Majority of the total body K+ is freely dissolved in the ___________

Cytosol of tissue cells

2

____________ constitutes the major osmotic component of the intracellular fluid

K+

3

Hypokalemia

When K+ (plasma) < 3.5 mEq/L

4

Hyperkalemia

When K+ (plasma) > 5 mEq/L

5

Significant hypokalemia causes sustained _________________

Depolarization

Whereas, hyperkalemia may hyper or hypo-polarize cells

Both lead to muscle and cardiac disturbances

6

Healthy K+ balance....

Excrete K+ in response to diet and withholding excretion when K+ is depleted

7

Moment to moment K+ regulation....

Muscle buffers K+(ECF) by taking up or releasing K+

This protects the ECF from large swings in K+ concentration

8

What hormones regulate K+?

insulin and epinephrine

9

Potassium is freely filtered into bowman's space....

65% of the filtered load is reabsorbed
Via the paracellular route
Driven by water reabsorption which concentrates K+

Flux is unregulated and varies with how much Na+/H20 is reabsorbed

10

Henle's loop reabsorbs approximately ________% of the filtered loads of K+

25%

The ascending limbs of Henle (both thin and thick) reabsorb K+

11

Bartter Syndrome (Type 3)

Mutations directly or indirectly involving the NKCC2

Symptomology similar to people on loop diuretics

12

What is the determinant of excitability of nerve and muscle, especially the heart?

K+