Changes

==Phosphorus==

==Overview==

Phosphorus is the third most abundent intracellular ion:  

Phosphorus is the third most abundant intracellular ion:  

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.

 

 

 

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==

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''.

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).

 

Phosphorus is excreted in the urine or saliva (particularly in ruminants).

===Hormonal Regulation===

===Hormonal Regulation===

[[Calcium#Parathyroid Hormone (PTH)|'''PTH''']]

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.

*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.

[[Calcium#Calcitriol (Active Vitamin D3)|'''Calcitriol''']]

[[Calcium#Calcitriol (Active Vitamin D3)|'''Calcitriol''']]

*Increases phosphorus absorbtion from the intestines

 

Calcitriol increases phosphorus absorption from the intestines.

==Pathology==

==Pathology==

Diseases relating to phosphorus homeostasis include:

Diseases relating to phosphorus homeostasis include:

*[[Bones Metabolic - Pathology#Primary hyperparathyroidism |Primary and Secondary Hyperparathyroidism]]

1. [[Hyperparathyroidism |Primary and Secondary Hyperparathyroidism]]

*[[Kidney Renal Failure - Pathology#Uraemia |Hyperphosphataemia]]

 

*Hypophosphatemia

2. Hyperphosphataemia

 

3. Hypophosphatemia

[[Category:Endocrine System - Anatomy & Physiology]]

[[Category:Endocrine System - Anatomy & Physiology]]

[[Category:Electrolytes]]

[[Category:Electrolytes]]

[[Category:To Do - A&P]]

[[Category:A&P Done]]

[[Category:Minerals]]