To achieve homeostasis, which 3 pressures need to be functioning?
Briefly explain Hydrostatic VS Osmotic pressures.
Osmotic (pull force), Oncotic (aka COP), and hydrostatic pressure (BP push force).
Hydrostatic pressure is caused by the flow of blood through vessels; it is the "push" force from within on the vessel walls.
Osmotic pressure is the pressure exerted on the vessel from the OUTSIDE (pull force) by the interstitial fluid. At the arteriole (closer to the heart) end of a vessel, hydrostatic pressure is greater than osmotic pressure, so fluid from the vessel leaks out. Thus, as you approach the venus end of that vessel, since fluid leaked out of the vessel before (and because you are farther away from the heart), the osmotic pressure is now greater than the hydrostatic pressure, so most of the fluid is pulled back into the vessel (intravascular space).