Difference between revisions of "Phosphorus"
| Line 1: | Line 1: | ||
==Overview== | ==Overview== | ||
| − | Phosphorus is the third most | + | Phosphorus is the third most abundant intracellular ion: |
1. Potassium | 1. Potassium | ||
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==Homeostasis== | ==Homeostasis== | ||
| − | Serum concentrations of phosphorus are maintained by dietary sources. It is absorbed across the intestine via '' | + | Serum concentrations of phosphorus are maintained by dietary sources. It is absorbed across the intestine via ''passive diffusion'' and ''[[Calcium#Calcitriol (Active Vitamin D3)|vitamin D]] mediated active transport''. Phosphorus is excreted in the urine or saliva (particularly in ruminants). |
===Hormonal Regulation=== | ===Hormonal Regulation=== | ||
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[[Calcium#Calcitriol (Active Vitamin D3)|'''Calcitriol''']] | [[Calcium#Calcitriol (Active Vitamin D3)|'''Calcitriol''']] | ||
| − | Calcitriol increases phosphorus | + | Calcitriol increases phosphorus absorption from the intestines. |
==Pathology== | ==Pathology== | ||
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[[Category:Endocrine System - Anatomy & Physiology]] | [[Category:Endocrine System - Anatomy & Physiology]] | ||
[[Category:Electrolytes]] | [[Category:Electrolytes]] | ||
| − | [[Category: | + | [[Category:A&P Done]] |
Revision as of 18:59, 7 January 2011
Overview
Phosphorus is the third most abundant intracellular ion:
1. Potassium
2. Magnesium
3. Phosphorus (as Phosphate)
Within the body it is found as Phosphate ions, or Phosphate within bone. The majority (~95%) is combined with Calcium in bone, forming Hydroxyapatite. Less than 1% is found in the extracelullar fluid.
Homeostasis
Serum concentrations of phosphorus are maintained by dietary sources. It is absorbed across the intestine via passive diffusion and vitamin D mediated active transport. Phosphorus is excreted in the urine or saliva (particularly in ruminants).
Hormonal Regulation
PTH mobilises phosphorus from bone, acting to increase the plasma concentration of P. It increases phosphorus loss in the urine and saliva, so ultimately, PTH acts to remove phosphorus from the body entirely.
Calcitriol increases phosphorus absorption from the intestines.
Pathology
Diseases relating to phosphorus homeostasis include:
1. Primary and Secondary Hyperparathyroidism
3. Hypophosphatemia
Links
Click here for the phosphorus homeostasis flashcards.