9th Evals 2018 - Renal Flashcards
GFR formula
GFR = Kf x ( Pg - Pb - Pig + Pib)
Kf
glomerular filtration coefficient
Pb
Bowman’s Capsule hydrostatic pressure
Pg
glomerular capillary hydrostatic pressure
Pi g
glomerular capillary colloid osmotic pressure
Ap
systemic arterial pressure
Re
efferent arteriolar resistance
Ra
afferent arteriolar resistance
decrease Re. due to constriction or dilation?
constriction
increase Ra
constriction
effect on GFR.
decrease in Kf
decrease in GFR
effect on GFR.
increase in Pb
decrease in GFR
effect on GFR.
decrease in Pg
decrease in GFR
effect on GFR.
decrease in Ap
decrease in Pg = decrease in GFR
effect on GFR.
decrease in Re
decrease in Pg = decrease in GFR
effect on GFR.
increase in Ra
decrease in Pg = decrease in GFR
At plasma concentration of glucose higher than occur at transport maximum (Tm), the
excretion rate of glucose increases with increasing plasma glucose concentrations
main driving force for water reabsorption by the proximal tubule epithelium
active reabsorption of sodium
site of major autoregulatory control in so far as GFR and renal plasma flow:
afferent arteriole
with autoregulation, fluctuations in systemic mean arterial pressure within range of 80 to 180 mmHg will result in
no significant change in either renal plasma flow or GFR
An increase in delivery of NaCl to the distal nephron is expected to decrease GFR because of the operation of
Tubuloglomerular feedback
renal clearance (of substance X)
The volume of plasma passing through the kidneys that has been totally cleared of Substance X in a given period of time
For a substance which is reabsorbed with a transport maximum (Tm), once this Tm is exceeded, the excretion of the substance
Parallels the rate of filtration of the substance
freely filtered;
not reabsorbed;
not secreted;
not metabolized by kidneys;
clearance=
equal to the GFR
freely filtered;
not reabsorbed;
SECRETED;
clearance=
GREATER THAN THE GFR
- Given a normal GFR of 125 ml/min, which of the following substances is being reabsorbed given their respective clearance rates?
a. Substance A with a clearance rate of 500ml/min b. Substance B with a clearance rate of 250ml/min
c. Substance C with a clearance rate of 125 ml/min
d. Substance D with a clearance rate of 75ml/min
D
.Tubular secretion is a process that
a. Is important in the regulation of Na+ balance
b. Is important in the regulation of plasma H+ concentration
c. Always occurs by active transport
d. Referstothemovementofsubstancesfromthetubularlumentothe
peritubular capillaries
B