Osmotic pressure?

[nr6unhH]

Can someone elaborate on osmotic pressure for me?
i've been searching and i really dont grasp the concept.

What exactly does osmotic pressure measure? What impact does it have? like increase/decrease of osmotic pressure in capillary. (sequences of events that occur)

difference b/t osmotic pressure and hydrostatic pressure?

thanks!

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[Isoprop]

Osmotic pressure is the pressure to stop osmosis from happening. The classic example is a U-tube separated by a semiperm membrane at the halfway point in the bottom. If you add solute to one side, it will take pressure to stop water from the other side to move in.

Hydrostatic pressure is good ol' "water pressure." It's pressure due to depth or because of a pump.

A good example to get the concepts cleared is to think of the nephron at the bowman's space and the glomerulus (making up the renal corpuscle). the heart will cause higher hydrostatic pressure in the glomerulus. This causes a movement of water from high hydrostatic pressure to low hydrostatic pressure. At the same time, blood as a lot of solutes (proteins) while the fluid in the Bowman's space is low in solutes. So the glomerulus has high osmotic pressure and the Bowman's space has low osmotic pressure. Water will move from B.S. to the glomerulus. Since the difference in hydrostatic pressure is greater than the difference in osmotic pressure, we see a net movement of water into the nephron.

Another good example would be capillaries and the accumulation of lymph fluid.