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Essential Ion and Compound Balance and Homeostasis - Anatomy & Physiology (view source)
Revision as of 15:12, 4 September 2008
, 15:12, 4 September 2008→Acid Base
In a situation of increased H<sup>+</sup> levels the body is said to be in a state of acidosis and the kidneys stop excreting HCO<sub>3</sub><sup>-</sup> and the tubular cells produce more bicarbonate. This results in more H<sup>+</sup> being buffered and the pH increases back to normal
In a situation of increased H<sup>+</sup> levels the body is said to be in a state of acidosis and the kidneys stop excreting HCO<sub>3</sub><sup>-</sup> and the tubular cells produce more bicarbonate. This results in more H<sup>+</sup> being buffered and the pH increases back to normal
===Buffers of H<sup>+</sup> in Urine===
[[Image:buffereg1ap.jpg|right|thumb|200px|<small><center>The HPO<sub>4</sub><sup>-</sup>Buffer System</center></small>]]
* Weak acids are filtered and act as buffers
* Ability depends upon pKa<sup>+</sup> and concentration
* Once all the bicarbonate has been reabsorbed the secreted H<sup>+</sup> combine with these instead.
* The H<sup>+</sup> ion is then excreted
=====The Role of Ammonium in the Proximal Tubule=====
[[Image:ammoniumproxitubap.jpg|right|thumb|200px|<small><center>The Role of Ammonium in the Proximal Tubule</center></small>]]
* The body is able to excrete H<sup>+</sup> as ammonium NH<sub>4</sub><sup>+</sup>. This is very useful as:
* It adds flexibility to renal acid base regulation and can help regulate NH<sub>4</sub><sup>+</sup>
* It is ionised, fat insoluble and trapped therefore is excreted
* It is easily replaced so is quite a good method
* Under physiological control
=====The Role of Ammonium in the Collecting Ducts=====
[[Image:ammoniumcollductap.jpg|right|thumb|200px|<small><center>The Role of Ammonium in the Collecting Duct</center></small>]]
* Very different mechanism
* No bicarbonate produced
* See diagram
==Calcium==
==Calcium==