Fizjologia nerek i dróg
moczowych

Dariusz Nowak

Renal Functions—20% C.O.

1. Excretion of Waste Products
2. Fluid Balance
3. Regulation of Hemodynamics
4. Mineral metabolism

Stężenie moczu



Izoosmotyczny- stężenie równe

stężeniu osocza krwi



Stężony – stężenie > stężenia
osocza krwi



Rozcieńczony – mocz mniej
stężony niż osocze



Co jest prawidłowe ?

Spójrzmy na
nefron

Juxtaglomerular Apparatus

Renal Hemodynamics—Basic
Mechanism



Glomerular filtration rate(GFR)
=permeability(hydraulic-oncotic)



Renal Blood Flow(RBF)



Vasoconstriction—AngII and NO

GFR and RBF

Increased Afferent

arteriole resistance

Decreases both GFR

and RBF

Increasing Efferent
arteriole resistance

Increases GFR
decreases RBF

Regulation of GFR



Neural—Beta1 receptor



Tubuloglomerular Feedback



Hormones— e.g. AngII(E>A),
endothelin factor, vasopressin, ANP,
PTH, NO

Clinical Assessment of GFR



Inulin—Perfect, too expensive



Creatinine—overestimates
GFRsecreted



Urea—antidiuresis absorbed by
medullary collecting duct(30-40% of
GFR)

Renin-angiotensin-
aldosterone System



Sodium



ECF Volume



Potassium



Blood pressure

Renin-
Angiotensin
System

Countercurrent Exchange

Regulation of Potassium



98% intracellular



Kidney excretes 90% of dietary
intake



Secretion by distal nephron primary
mechanism.



70% reabsorbed by PCT, 90% by
distal nephron

Factors Regulating Potassium



Principal cells of CCT activated by
aldosterone.



11B hydroxysteroid dehydrogenase
tissue specific enzyme



Secretion is stimulated by alkalosis

Calcium



Most common divalent ion in body



Intestine, bone, and renal regulation



Filterable calcium increases with
acidemia



2% of daily intake secreted in urine