Regarding excretion of Na+:
a. Not dependent on aldosterone.
b. Major share of GF osmolarity with associated ions.
c. It passively diffuses in proximal tubules.
d. In distal tubules it is exchanged for K+
e. Coupled with K+
b. Na+ excretion is influenced by mineralocorticoids (mainly aldosterone):↑ reabsorption. The GF is isoosmolar with plasma i.e. Na is the major electrolyte. 90% of Na is actively (not passively) reabsorbed in the PCT. K is excreted from DCT in exchange with Na (not the reverse and not coupled with it).
a. Not dependent on aldosterone.
b. Major share of GF osmolarity with associated ions.
c. It passively diffuses in proximal tubules.
d. In distal tubules it is exchanged for K+
e. Coupled with K+
b. Na+ excretion is influenced by mineralocorticoids (mainly aldosterone):↑ reabsorption. The GF is isoosmolar with plasma i.e. Na is the major electrolyte. 90% of Na is actively (not passively) reabsorbed in the PCT. K is excreted from DCT in exchange with Na (not the reverse and not coupled with it).