Changes

* In cases of increased K⁺

* In cases of increased K⁺

* Increased sodium pump activity increases the amount of K⁺ in cells to reduce plasa K⁺

* Increased Na⁺ / K⁺ ATPase pump activity increases the amount of K⁺ in cells to reduce plasa K⁺

* Generally not excreted

* Generally not excreted

* However if plasma K⁺ is still high aldosterone is stimulated

* However if plasma K⁺ is still high aldosterone is stimulated

* Causes pottassium secretion

* Causes pottassium secretion

** Pottassium via apical leak channels in the principal cells

** Pottassium leaves via apical leak channels  

* Very tightly regulated system

* Very tightly regulated system

** Allows large increase in K⁺ to have a miniscule effect on plasma K⁺

** Allows large increase in K⁺ to have a miniscule effect on plasma K⁺