Equations/Values- Exam 3 Flashcards
Filtration Fraction
GFR/RBF
Filtration
GFR x [Plasma]
Excretion
Filtration - Reabsorption + Secretion
Plasma Osmolarity
(2.1) x (Plasma sodium concentration)
What percent of PAH in RBF is removed?
90%
Net force for reabsorption
10 mmHg
Pc
13 mmHg
“Pi”c
32 mmHg
Pif
6 mmHg
“Pi”if
15 mmHg
Normal reabsorption rate
124 mls/min
Filtration coefficient
Reabsorption rate/ Net force
constant under most conditions
ADH MOA
V2 receptors, increases cAMP, activates protein kinases, moves aquaporin-2
Chronic Increased ADH
Stimulates formation of aquaporin-2 molecules
Low SNS stimulation
alpha-receptors on epithelial cells
decreses sodium/water excretion
Stimulates renin -> Angiotensin II
Clearance equation
Cs = Us x V / Ps Us= urine solute concentartion v= urine flow Ps = plasma solute concentration
Also, Urinary Excretion/Plasma concentration
Urinary Excretion
Us x V
How to estimate GFR? (if freely filtered)
= to urinary excretion
What does a 4 fold increase in creatinine mean?
GFR is 1/4 normal
How to estimate RPF (if freely filtered?
= Cs
How to calculate RPF from PAH clearance?
PAH Clearance/ 0.9
Total Blood Flow equation
Plasma Flow / (1-HCT)
Acidosis causes what to K+ secretion?
Decreases K+ secretion
inhibits Na/K pump
Prolonged acidosis causes what to K+ secretion?
Increases K+ secretion
Decreased sodium reabsorption, increased tubular flow
Salt H20 g/mol
58.5
Inuline estimates what
Water absoprtion
Inulin of 3 means what
1/3 in tubule
Absorption
Filtered Load- Excretion
Secretion
Excretion - Filtered load
