Difference between revisions of "Phosphorus"
Jump to navigation
Jump to search
Line 1: | Line 1: | ||
− | == | + | ==Overview== |
Phosphorus is the third most abundent intracellular ion: | Phosphorus is the third most abundent intracellular ion: | ||
− | |||
− | |||
− | |||
− | Within the body it is found as Phosphate ions or Phosphate within bone. | + | 1. Potassium |
− | The majority (~95%) is combined with Calcium in bone, forming Hydroxyapatite. Less than 1% is found in the extracelullar fluid. | + | 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== | ==Homeostasis== |
Revision as of 16:32, 5 January 2011
Overview
Phosphorus is the third most abundent 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
- Mobilises phosphorus from bone, acting to increase plasma concentration of P
- Increases phosphorus loss in the urine and saliva, acting to decrease plasma concentration
So ultimately, PTH acts to remove phosphorus from the body entirely.
- Increases phosphorus absorbtion from the intestines
Pathology
Diseases relating to phosphorus homeostasis include:
- Primary and Secondary Hyperparathyroidism
- Hyperphosphataemia
- Hypophosphatemia