Flashcards in Physio: Kidney Solute Processing: Potassium, Calcium, Magnesium Deck (12):
Majority of the total body K+ is freely dissolved in the ___________
Cytosol of tissue cells
____________ constitutes the major osmotic component of the intracellular fluid
When K+ (plasma) < 3.5 mEq/L
When K+ (plasma) > 5 mEq/L
Significant hypokalemia causes sustained _________________
Whereas, hyperkalemia may hyper or hypo-polarize cells
Both lead to muscle and cardiac disturbances
Healthy K+ balance....
Excrete K+ in response to diet and withholding excretion when K+ is depleted
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
What hormones regulate K+?
insulin and epinephrine
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
Henle's loop reabsorbs approximately ________% of the filtered loads of K+
The ascending limbs of Henle (both thin and thick) reabsorb K+
Bartter Syndrome (Type 3)
Mutations directly or indirectly involving the NKCC2
Symptomology similar to people on loop diuretics