Kidney function Flashcards
What are 6 functions of kidneys?
- Ion balance
- Osmotic balance
- Blood pressure
- pH balance
- Excretion of nitrogenous waste and other toxins
- Hormone production
What is the primary osmotically active ion in the extracellular fluid?
Sodium
What is hyperatremia?
Na+ concentration is too high in ECF
What is hypoatremia?
Na+ concentration is too low in ECF
What is hyperkalemia?
K+ concentration is too high in ICF
What is hypokalemia?
K+ concentration is too low in ICF
What is the primary osmotically active ion in the intracellular fluid?
K+
How do kidneys regulate the osmotic balance?
They regulate the volume and concentration of urine produced, which regulates the osmotic balance of the blood by excreting or retaining salts and water
How do kidneys regulate the blood pressure?
They regulate the blood volume, which regulates the pressure by extension
How do kidneys regulate the pH balance of the blood?
They can retain or excrete H+ or HCO3 into the urine, which changes the pH. Both NH3 creates acids or bases and urea production uses up bicarbonate, which creates an imbalance that needs to be fixed
What does it mean when the U/P ratio = 1?
Urine is isosmotic relative to the blood, so water and solutes are secreted in relation to the plasma concentrations and the osmotic pressure of the blood isn’t affected
What does it mean when the U/P ratio < 1?
Urine is hyposmotic relative to the blood. More water will be secreted and salts will be retained
What does it mean when the U/P ratio > 1?
Urine is hyperosmotic relative to the blood. More salts will be secreted and water will be retained
What is the U/P ratio of marine teleost urine?
U/P > 1. The urine is hyperosmotic because of the high concentration of divalent atoms
What is the U/P ratio of freshwater teleost urine?
U/P < 1. The urine is hyposmotic because the fish is retaining salts
