Renal System 2 Flashcards
7 functions of the kidneys?
- Regulation of water and electrolyte balance
- Regulation of arterial pressure
- Excretion of metabolic waste products
- Regulation blood pH
- Regulation of erythrocyte production
- Regulation of hormone production
- Regulating blood glucose levels
Symptoms when things go wrong in the kidneys?
Swelling High blood pressure Shortness of breath Fatigue Nausea
Are the kidneys linked to homeostasis?
Yes (eg blood pressure, water and electrolyte balance, pH, waste product removal
Describe osmosis?
The movement of water through a selectively permeable membrane from an area of lower solute concentration (high water concentration) to an area of higher solute concentration (low water concentration)
What is osmotic pressure?
The pressure required to prevent net water movement (aka applied pressure)
What is osmolarity?
A measure of the osmotic pressure exerted by a solution across a perfect semi-permeable membrane compared to pure water
What is osmolarity dependent on?
The number of particles in solution (but independent of the nature of the particles)- is basically concentration
What is hyperosmotic?
A solution with a higher osmolarity than another (300mm NaCl vs 300mm urea)
What is an isosmotic solution?
Two solutions with the same osmolarity (150mm/NaCl vs 300mm urea)
What is hyposmotic?
A solution with a lower osmolarity than another (150mm urea vs 150mm NaCl)
What does tonicity take into account?
The concentration of a solute and the ability of the particle to cross a semi-permeable membrane (NaCl- low permeability)
What is hypertonicity?
When a solution with a higher POsm than another, and water will leave causing shrinkage
What is isotonicity?
Two solutions with the same POsm, so no net water movement
What is hypotonicity?
A solution with a lower POsm than another. Water will move into the cell causing swelling
What are the mechanisms of dehydration?
- Excessive loss of water from ECF
- ECF osmotic pressure rises
- Cells lose water to ECF by osmosis, cells shrink