Capsular hydrostatic pressure (CHP) is a back-pressure that opposes filtration. As the filtrate is forced into the capsular space, it meets 2 forms of resistance: the wall of the capsule and the fluid that has already filled the renal tubule.
This pressure drives fluid out of the capillary (i.e., filtration), and is highest at the arteriolar end of the capillary and lowest at the venular end.
Horses sleep while standing, unless it is necessary for them to get REM sleep. The amount of REM sleep needed is not much, so they will spend most of their time when sleeping, standing.
