+ h 2 co 3 atp lumen h + 3na + carbonic anhydrase early proximal tubule h 2 o + hco 3 - h 2 co 3...
TRANSCRIPT
+
H2CO3
ATP
Lumen
H+
3Na+
Carbonic anhydrase
Early Proximal tubule
H2O
+ HCO3
-
H2CO3 Carbonic anhydrase
CO2 H2O
HCO3- +
+
Na+
Glucose 2K+
Na+
H+
Base-
Cl-
(65 -80)
K+ H2O Cl-
Blood vessel
Na+ Na+ Na+ Na+
Na+ Na+ Na+ Na+ Na+
Na+ Na+ Na+
Na+ Na+ Na+ Na+
CO2
HCO3- H+
+
H2CO3
ATP
Lumen
H+
Na+
Carbonic anhydrase
Early Proximal tubule
H2O
+ HCO3
-
H2CO3 Carbonic anhydrase
CO2 H2O
HCO3- +
+
Na+
Glucose K+
Na+
H+
Base-
Cl-
(65 -80)
K+ H2O Cl-
Blood vessel
Na+ Na+ Na+ Na+ Na+
Na+ Na+ Na+ Na+ Na+
Na+ Na+ Na+ Na+ Na+
Na+ Na+ Na+ Na+ Na+
CO2
HCO3- H+
Glucose titration curve
600
400
200
800
2000
400
600
800
Glucose
Glucose Excreted
Glucose Reabsorbed
GFR = 125mL/min
Glucose Filtered
[Glucose] plasma (mg/dL
K = RPT
TmG = 375mg/min
Glu
cose
flux
(mg/
min
)
Splay
Splay
Changes in % of renal filtrate
Proximal tubule Loop of Henle Distal tubule Collecting tubule
Fraction remaining in tubular fluid
Na+
Water
Urea
D
A
C
B
0.02
0.50
0.20
0.10
0.05
1.0
5.0
10.0
20
50
100
2.0
Changes in % of renal filtrate
Proximal tubule Loop of Henle Distal tubule Collecting tubule
Fraction remaining in tubular fluid
Na+
GlucoseWater
Urea
Inulin
Creatinine
F
D
A
C
B
E
Case 1A 75-year-old man is brought to the emergency department
because of diarrhea and vomiting for the last 24 hours. The patient lives at home with his son, and his son states that his father has been unable to take in much fluid since his symptoms began. On examination, his mucous membranes are dry and his blood pressure is 90/60 mm Hg.
What changes do you expect in the renal plasma flow (RPF) of
this patient?Would there be any change in his glomerular filtration rate
(GFR)?What impact would this patient physiological state have on his
filtration fraction?
RPF GFR FF
• A 27-year-old woman is being monitored in the intensive care unit after she sustained head trauma in a motor vehicle accident 3 days ago. She has undergone computed tomographic imaging of her head, which revealed cerebral swelling but no evidence of hemorrhage or brain herniation. The patient has been in critical but stable condition. The nurse calls the physician because the patient has developed hypernatremia and has had a significant increase in dilute urine output. The findings are confirmed, and it is determined that the patient has central diabetes insipidus as a result of the head trauma.
• • How are antidiuretic hormone (ADH) levels affected in patients with this
condition?• What is the effect of high ADH on the late distal tubule and collecting ducts?• How does free-water clearance change in the presence of ADH?
Solute reabsorption at PCT
Cl-
+
H2CO3
ATP
Lumen
H+
Na+
Carbonic anhydrase
Early Proximal tubule
H2O
+ HCO3
-
H2CO3 Carbonic anhydrase
CO2 H2O
HCO3- +
+
Na+
Glucose K+
Na+
H+
Base-
Cl-
(65 -80)
K+ H2O Cl-
Blood vessel
Na+ Na+ Na+ Na+ Na+
Na+ Na+ Na+ Na+ Na+
Na+ Na+ Na+ Na+ Na+
Na+ Na+ Na+ Na+ Na+
CO2
HCO3- H+
ATP
Lumen
Na+
Thick ascending loop of Henle
Na+
K+
Ca2+
(15 - 20)
CA2+
Na+
Cl-
Cl-
Blood vessel
Na+ Na+ Na+
Na+ Na+ Na+
2Cl-
Na+
K+
Na+ K+
K+ K+ K+ K+ K+ K+
K+
K+
Cl- Cl-
Cl-
Cl-
Cl-
Cl-
Cl-
Cl- Cl-
Cl-
Ca2+ Ca2+
Ca2+
Ca2+
Ca2+
Ca2+
Ca2+
Na+ Na+ Na+ Na+
ATP
Lumen
Na+
Early distal convoluted tubule
K+
Ca2+
K+
Cl-
2Cl-
Na+
K+
K+
Mg 2+ ,
Cl-
Diffusion down the electrochemical gradient
Loop diuretics 5%
Blood vessel
ATP
Lumen
Na+
Collecting Duct
K+
Cl-
Na+
K+
H20
K+ sparing diuretics
5 - 7%
V2 ADH
Principal Cell
Intercalated cell
R
Water channel molecules
Blood vessel
Aldosterone
H2OH2O H2O H2O
H2OH2O H2O H2O
H2O H2O H2O
Na+ Na+
Na+ Na+ Na+ Na+ K+ K+
K+
ATP
Lumen
Na+
Collecting Duct
K+
Ca2+
Cl-
Na+
K+
H20
Mg 2+ ,
K+ sparing diuretics
5 - 7%
V2 ADH
Principal Cell
Intercalated cell
ATP
H+
HCO3-
Cl-
R
Water channel molecules
Blood vessel
K+
Aldosterone
H2OH2O H2O H2O
H2OH2O H2O H2O
H2O H2O H2O
Na+ Na+
Na+ Na+ Na+ Na+ K+ K+
K+
Glucose titration curve
600
400
200
800
2000
400
600
800
Glucose
Glucose Excreted
Glucose Reabsorbed
GFR = 125mL/min
Glucose Filtered
[Glucose] plasma (mg/dL
K = RPT
TmG = 375 mg/min
Glu
cose
flux
(mg/
min
)
CA
K
I
H
F