Changes

==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 absorbtion from the intestines.

==Pathology==

==Pathology==