Tubular Transport Flashcards
Glomerular filtration rate (GFR) is the sum of ______ and driven by ______
- filtration rates of all functioning nephrons per unit of time
- driven by Starling forces
What is creatine used to measure?
GFR because it’s not reabsorbed or secreted
GFR is used to determine…
health of kidney function
- decrease in GFR = increase in kidney disease progression
Hydrostatic pressure of glomerular capillaries (Pgc) is usually at what mmHg?
58 mmHg
- outward force that moves fluid from glomerular capillaries to Bowman’s capsule
Hydrostatic pressure of glomerular capillaries (Pgc) is maintained high by…
- large diameter of afferent arterioles
- small diameter of efferent arterioles
What is the main force that affects GFR?
Hydrostatic pressure of glomerular capillaries (Pgc)
What happens if there is an increase in hydrostatic pressure of glomerular capillaries (Pgc)?
- decrease in afferent arteriole resistance
- increase in efferent arteriole resistance and renal arteriolar pressure
Hydrostatic pressure of fluids in Bowman’s capsule (Pb) is usually at what mmHg?
15 mmHg
- inward force that opposes filtration
Hydrostatic pressure of fluids in Bowman’s capsule (Pb) increases when…
nephron is obstructed
- makes sense since it opposes filtration
Colloid osmotic pressure of glomerular capillary proteins (PIgc) is usually at what mmHg?
30 mmHg
- inward force that opposes filtration
Colloid osmotic pressure of Bowman’s capsule is usually at…
zero
How do disease states affect intrinsic permeability and glomerular SA available (k)?
decrease K because there is a decreased SA
What can increase intrinsic permeability and glomerular SA available (k)?
drugs that dilate afferent arteriole
GFR is a function of…
filtration pressure and filtration coefficient of the filtration membrane over time
How can you measure GFR indirectly?
by measuring renal clearance, which is the volume of plasma cleared of a given substance by kidney over time