Here's why:
* Filtration is a passive process where fluids and small solutes move from an area of high pressure to an area of low pressure.
* Blood pressure provides the driving force for filtration in the body.
* The kidneys are a prime example of filtration. Blood pressure pushes fluid and small molecules (like waste products) from the capillaries into the nephrons, where filtration occurs.
While other transport mechanisms exist (like diffusion, osmosis, active transport), these rely on other factors like concentration gradients or energy expenditure. Filtration is uniquely dependent on blood pressure.
