Renal Physiology Lecture 2: Potassium Balance

Question 1

Function of potassium

Answer 1

• Protects resting membrane potential and normal cellular function
• Particularly important for excitable cells
  
  • Heart, neurons, skeletal muscle

Question 2

Hypokalemia

Answer 2

lower than normal potassium level in your bloodstream

• Muscle weakness, dysfunction of respiratory & cardiac muscle

Question 3

Hyperkalemia

Answer 3

a potassium level in your blood that’s higher than normal

• Initial increase in excitability followed by depression due to impaired repolarization
  
  • i.e cardiac arrhythmia

Question 4

How do kidneys contribute to K balance?

Answer 4

Question 5

What can fluctuate K levels?

Answer 5

renal or GI dysfunction

Question 6

What can diuretic drugs cause?

Answer 6

excessive K loss in urine

Question 7

Aldosterone effect on K

Answer 7

regulate K balance

• High K stimulates release from adrenal cortex
• Acts at distal tubule to stimulate NA-K-ATPase
  
  • enhance K excretion