Renal physiology L1 Flashcards
What are the functions of the kidney?
-Regulation of water and electrolyte balance
-Regulation of blood volume & pressure
-maintenance of blood osmolarity
- Excretion of metabolic waste products (e.g. urea and creatinine) or foreign chemicals (e.g.
pesticides, drugs, or food additives) from the body
-Regulation of blood pH (e.g. via regulation of H+ and HCO3-)
-Regulation of erythrocyte production
-Regulation of hormone production e.g. calcitriol (vitamin D)
-Regulating blood glucose levels
What are the functions of the kidney?
-Regulation of water and electrolyte balance
-Regulation of blood volume & pressure
-maintenance of blood osmolarity
- Excretion of metabolic waste products (e.g. urea and creatinine) or foreign chemicals (e.g.
pesticides, drugs, or food additives) from the body
-Regulation of blood pH (e.g. via regulation of H+ and HCO3-)
-Regulation of erythrocyte production
-Regulation of hormone production e.g. calcitriol (vitamin D)
-Regulating blood glucose levels
osmolality vs osmolarity
osmolality- the measure of the osmols(Osm) of solute per kilogram of solvent (osmol/kg or Osm/kg)
osmolarity- the number of osmoles of solute per liter(L) of solution( osmol/L or Osm/L)
what is the plasma osmolarity?
~ 300 mOsmol/L
how does dialysis work?
One needle will slowly remove the blood and transfer it to a machine called a dialyzer or dialysis machine. The dialysis machine is made up of a series of membranes that act as filters and a special liquid called dialysate. The membranes filter waste products from your blood, which are passed into the dialysate fluid.
the solution has high solute concentration so water moves across
tonicity
takes into account the concentration of the solutes and the ability of the particles to cross a semi-permeable membrane.
the effect that a solution has on the cell
Hypertonic, Isotonic, Hypotonic solution
what is the effect on dehydration ( loss of water) on the cell?
ECF osmolarity increases ECF osmotic pressure rises, which draws water out of the cell-> cell shrinks
what is the effect of excess hydration?
ECF osmolarity decreases, ECF osmotic pressure falls-> water moves into the cell
how much of total body weight does water make up in females and males?
female ~50 % body weight
males ~ 60% body weight
Infant ~ 65-75%
how much of body fluids do intracellular fluid (ICF) and ECF account for?
ICF- 2/3 of the body’s fluids
ECF- 1/3 of the body’s fluids
~20% of extracellular fluid is blood plasma
~80% of ECF is interstitial fluid(between cells)
Body fluid compartment for a 70 kg male
60% fluid= 42L
2/3 ICF= 28 L
1/3 ECF= 14 L
(20% plasma= 2.8L)
(80% interstitial= 11.2 L)
how much plasma is in the blood?
~55%
Thus is 2.8 L of plasma then 5 L of blood
why maintaining osmolarity is so important?
-setting the membrane potential
-generating electrical activity in nerve and muscle
-the initiation of muscle contraction
-providing the energy for the uptake of nutrients and the expulsion of waste products
-generation of intracellular signaling cascades
-Cells need to be at the right osmolarity to function properly
what are the major sources of water intake?
-metabolism ( 8%)
-foods(28%)
-beverages( 64%)
what are the major sources of water output?
feces- 4 %
lungs 12 %
Skin 24%
urine 60%
what is the concentration gradient for K+, Na+, and Cl-?
