Final answer:
Glomerular filtration is the process in the formation of urine that decreases with lower blood pressure and increases with higher blood pressure, as it's directly dependent on the hydrostatic pressure of the blood in the glomerulus.
Step-by-step explanation:
The process of urine formation that decreases when the blood pressure decreases, and increases when the blood pressure increases, is known as glomerular filtration. This process occurs in the glomerulus of the kidney and is influenced by the hydrostatic pressure exerted by the blood within the glomerular capillaries. When blood pressure drops, this pressure also drops, leading to a decrease in glomerular filtration rate (GFR). Conversely, when blood pressure rises, hydrostatic pressure in the glomerulus increases, resulting in an increased GFR. Glomerular filtration is the first step in urine formation, and changes in blood pressure affect it directly due to its reliance on the hydrostatic pressure of the blood.